ESP DESCRIPTION

DESCRIPTION      The ABS electronic anti-lock braking system regulates the braking pressure transmitted to the wheels, preventing them from losing grip whatever the tyre and road conditions. The ABS system is linked to the ESP (Electronic Stability Program) system which controls the stability of the vehicle and intervenes, if necessary, on the drive torque, braking the wheels in a differentiated manner: if grip is lost the ABS helps to return the vehicle to the correct path. The ABS control unit, in the most comprehensive version, as well as the ESP function, also implements the A.S.R. (Anti Slip Regulation), Hill Holder, H.B.A. (Hydraulic Brake Assist) and M.S.R. (engine brake torque regulation during downshifting). The ESP system intervenes on the engine and on the brakes, producing a stabilising torque when the ABS sensors detect conditions that could cause the vehicle to slip. A flashing warning light in the instrument cluster signals that the system has intervened and notifies the driver that the car is in critical grip and stability conditions. ATTENTION: For correct operation of the ESP and ASR systems it is vital that the tyres are the same make and the same type on all wheels and that they are in perfect condition and, above all, the recommended type, make and size. The ESP system has a specific sensor in addition to those for the ABS: a yaw control unit detects vehicle rotation about the vertical axis and side acceleration (centrifugal force). It also uses steering sensor signals from the electric steering control unit supplied via the CAN. A longitudinal acceleration sensor is also provided with the Hill Holder function which is incorporated into the same yaw control unit. The ESP system also uses the information from the pressure sensor which measures pressure in the hydraulic circuit: this sensor is built into the hydraulic control unit. The H.B.A. system aids the driver in emergency braking situations when the brake pedal is activated quickly and in poor load maintenance conditions. The system intervenes when the pressure gradient exceeds a certain level (fast application of brake pedal - emergency braking). This multiplies the braking pressure at the wheels applied by the driver, thereby producing the maximum deceleration that can be achieved. NOTE: Following sharp braking which causes considerable deceleration, the Body Computer receives the vehicle speed signal from the ABS control unit and activates the hazard warning lights. When this deceleration value goes below a pre-set level, the hazard function is automatically deactivated

See: DIRECTION INDICATORS / HAZARD WARNING LIGHTS (Container)

The ESP system is always combined with the ASR system.

The ASR system increases the active safety and stability of the vehicle, controlling the slipping of the drive wheels: if transmission of excessive power causes slip, the system cuts in with the co-operation of the engine management control unit, to reduce engine power output. If, on the other hand, slip is detected at one wheel only, the system cuts in to brake only the slipping wheel by means of the wheel's modulating solenoid valve.

The ASR is automatically activated whenever the engine is started: the system can be switched off using the "ASR OFF" button located in the panel controls in the centre of the dashboard. When the system is off, an LED in the button and a warning light in the control panel come on simultaneously. The ESP function, on the other hand, is automatically activated each time the engine is started up and cannot be turned off.

The MSR system (engine drive regulator) is an integral part of the ASR, which intervenes if there is a sudden change to a lower gear, by supplying torque to the engine, thereby preventing excessive drive at the drive wheels which, especially in poor grip conditions, could lead to a loss of vehicle stability.

The Hill Holder system is designed to assist the driver when setting off on an incline. In effect, the HH is capable of automatically providing sufficient braking torque to keep the vehicle stationary until the clutch is fully released and the engine torque is sufficient to start the vehicle comfortably.

The HH is automatically activated when the brake pedal is depressed, in conjunction with the following conditions: vehicle speed equal to zero, gradient more than 2% and clutch pedal pressed.

The moment the brake pedal is released, with all other conditions being equal, the Hill Holder keeps the braking system pressurised for 2 seconds to allow the driver to move his/her foot from the brake pedal to the accelerator pedal without the vehicle slipping backwards and without using the parking brake.

When 2 seconds have elapsed the system is automatically deactivated and gradually releases the braking pressure without any departure having taken place. During this release stage you may hear a typical mechanical brake release noise. This indicates that the car is about to move.

The HH is not activated when reverse gear is engaged.

If there are any faults in the ESP / ASR system it will automatically disengage. The relevant warning light will come on in the instrument cluster and a message will be shown on the display. At the same time, the Hill Holder device fault will activate the relevant warning light.

The direct battery supply lines for the control unit (pump and solenoid valves) are protected by two dedicated fuses located in the engine compartment junction unit. The ignition-operated power supply is protected in the same way by a dedicated fuse.

DIAGNOSIS -THE STARTER DONT WORK

NOTE:  When the key is turned to the ON position, the instruments light up but the starter motor does not turn.   Test results 1 STARTER MOTOR CONNECTIONS CHECK All OK Problems encountered Operation Check the connections between battery, ignition switch and starter motor See: STARTING AND RECHARING (Container) Move on to Step 2 Connections not correct Restore correct wiring See: STARTING AND RECHARING (Container) 2 IGNITION SWITCH CHECK All OK Problems encountered Operation Check the condition of the ignition switch and that it is working properly by carrying out See: IGNITION SWITCH EFFICIENCY CHECK (Info) Move on to Step 3 Ignition switch fault Replace the ignition switch See: IGNITION SWITCH ASSEMBLY - R+R (Info) 3 STARTER MOTOR CHECK All OK Problems encountered Operation Check the condition of the starter motor and that it is working properly See: STARTING AND RECHARING (Container) End of diagnosis Fault in the starter motor Replace the starter motor See: STARTER MOTOR - R.R. (Info)

Diagnostic steps of diesel temperature

Turbo Common rail injection   STEP CHECKS TO BE CARRIED OUT SOLUTION IF CHECK NOT OK 1 At operating temperature, with the engine idling and all the electrical supplies disabled, a value of between 10 and 80°C should be read. The test may be considered concluded. Proceed to Step 2 2 Turn the ignition key to the STOP position. Disconnect the wiring harness connector from connector A of the engine management control unit. Turn the key to the IGNITION-ON position. Measure the voltage between Pin 13 (wiring side) of the control unit See: ENGINE MANAGEMENT CONTROL UNIT (Container) and Ground, ensuring that it is less than 0.3 V. Proceed to Step 4 Proceed to Step 3 3 Turn the ignition key to the STOP position. Measure the resistance between Pin 13 (wiring side) of the control unit See: ENGINE MANAGEMENT CONTROL UNIT (Container) and Ground, ensuring that it is greater than 500 kOhm Proceed to Step 4 4 Disconnect the wiring harness connector from the fuel temperature sensor. Measure the resistance between Pin 13 (wiring side) of the control unit See: ENGINE MANAGEMENT CONTROL UNIT (Container) and Pin 1 (wiring side) of the sensor See: FUEL TEMPERATURE AND WATER IN FUEL FILTER SENSOR (Container) ensuring that it is less than 5 Ohm Restore, or if necessary replace, the electric wiring between the engine management control unit and the resistor See: DIESEL ENGINES ELECTRONIC MANAGEMENT (Container) 5 Measure the resistance between Pin 61 (wiring side) of the control unit See: ENGINE MANAGEMENT CONTROL UNIT (Container) and Pin 2 (wiring side) of the sensor See: FUEL TEMPERATURE AND WATER IN FUEL FILTER SENSOR (Container) ensuring that it is less than 5 Ohm Restore, or if necessary replace, the electric wiring between the engine management control unit and the sensor See: DIESEL ENGINES ELECTRONIC MANAGEMENT (Container) 6 Replace the sensor See: FUEL FILTER ASSEMBLY - R.R. OR REPLACE (Info) and ensure that the fault has been resolved Restore the original resistor and replace the engine management control unit See: DIESEL ELECTRONIC INJECTION CONTROL UNIT - R.R (Info)

Injection system controle

VARIABLE VALVE TIMING CHECK

STEP	CHECKS TO BE CARRIED OUT	SOLUTION IF CHECK NOT OK
1	Checking the variable camshaft timing system Disconnect the connector of the variable camshaft timing solenoid valve. Start up the engine. Connect the solenoid valve terminals to the battery for a few seconds. Check that there is a considerable variation in the idling speed.	Replace the solenoid valve of the variable camshaft timing system See: PHASE TRANSFORMER ELECTROMAGNET - R.R. (Info) Replace the variable camshaft timing system unit See: PHASE TRANSFORMER ON CAMSHAFT IN CYLINDER HEAD - R.R. (Info)

DIAGNOSIS AND TESTING

The brake system operates by transferring effort applied to the brake pedal by the driver to the brakes at each wheel. The braking effort is distributed to each wheel, using a hydraulic system. The system is assisted using a vacuum brake booster that reduces pedal effort and increases hydraulic pressure. The parking brake operates on the rear wheels and is applied using a hand operated control. Inspection and Verification NOTE: Before carrying out any diagnosis, make sure that the brake system warning indicator is functional. Verify the customer concern. Visually inspect for obvious signs of mechanical or electrical damage. Visual Inspection Chart Mechanical Electrical Tire pressure(s) Wheels and tires Fluid leak(s) Electrical connector(s) Wiring harness(s) Switch(es) If an obvious cause for an observed or reported concern is found, correct the case (if possible) before proceeding to the next step. If the cause if not visually evident, verify the symptom and refer to the Symptom Chart. Road Test Carry out a road test to compare actual vehicle braking performance with the performance standards expected by the driver. The ability of the test driver to make valid comparisons and detect performance deficiencies will depend on experience. The driver should have a thorough knowledge of the brake system operation and accepted general performance guidelines to make good comparisons and detect performance concerns. An experienced technician will always establish a route that will be used for all brake diagnosis road tests. The road selected will be reasonably smooth and level. Gravel or bumpy roads are not suitable because the surface does not allow the tires to grip the road equally. Crowned roads should be avoided because of the large amount of weight shifted to the low set of wheels on this type of road. Once the route is established and consistently used, the road surface variable can be eliminated from the test results. Before a road test, get a complete description of the customer concerns or suspected condition. From the description, the technician will be able to match possible causes with symptoms. Certain components will be identified as possible sources while others will be eliminated by the evidence. More importantly, the customer description can reveal unsafe conditions which should be checked or corrected before a road test. The description will also help form the basic approach to the road test by narrowing the concern to specific components, vehicle speed or conditions. Begin the road test with a general brake performance check. Using the description of the concern, test the brakes at different vehicle speeds using both light and heavy pedal pressure. Determine if the concern is in the front or rear braking system. First use the foot brake and then the parking brake. If the condition (i.e. pull, vibration, pulsation) occurs only on operation of the parking brake, the concern is in the rear brake system. If the condition occurs when the foot brake is depressed, the concern is in the front brake system. Avoid locking the brakes and sliding the tires. This condition will not indicate brake efficiency. A heavily braked but turning wheel will stop the vehicle in a shorter distance than locked wheels. If the concern becomes evident during this check, make sure it fits the description given before the road test. If the concern is not evident, attempt to duplicate the condition using the information from the description. If a concern exists, use the Brake System Symptom Chart in order to isolate it to a specific sub-system and condition description. From this description, a list of possible sources can be used to further narrow the cause to a specific component or condition. Symptom Possible Sources Action Brakes pull or drift * Worn or damaged brake shoes or brake pads and linings. * INSTALL new brake shoes or brake pads. REFER to: Brake Pads (206-03 Front Disc Brake, Removal and Installation), Brake Pads (206-04 Rear Disc Brake, Removal and Installation). * Abnormal wear or distortion of front brake disc(s). * INSTALL a new front brake disc. REFER to: Brake Disc (206-03 Front Disc Brake, Removal and Installation). * Incorrect rear brake adjustment. * ADJUST the parking brake cable. REFER to: Parking Brake Cable Adjustment (206-05 Parking Brake and Actuation, General Procedures). * Incorrect wheel alignment adjustment. * ADJUST the wheel alignment. REFER to: (204-00 Suspension System - General Information) Front Toe Adjustment (General Procedures), Rear Toe Adjustment (General Procedures). * Incorrect wheel bearing preload adjustment. * ADJUST or INSTALL a new wheel bearing. REFER to: Wheel Hub (204-01 Front Suspension, Removal and Installation). * Grease or fluid on the brake shoes or brake pads; glazed linings. * INSTALL new brake shoes or brake pads. REFER to: Brake Pads (206-03 Front Disc Brake, Removal and Installation), Brake Pads (206-04 Rear Disc Brake, Removal and Installation). * Stuck or seized wheel cylinders or brake calipers. * INSTALL a new wheel cylinder or brake caliper. REFER to: Brake Caliper (206-03 Front Disc Brake, Removal and Installation), Brake Caliper (206-04 Rear Disc Brake, Removal and Installation). The red brake warning indicator is always on * Low brake fluid level. * FILL the reservoir. CHECK the brake and clutch system for leaks including brake fluid in the brake booster. * Leaking brake master cylinder primary piston cup. * INSTALL a new brake master cylinder. REFER to: (206-06 Hydraulic Brake Actuation) Brake Master Cylinder - Vehicles With: LHD FWD (Removal and Installation), Brake Master Cylinder - Vehicles With: LHD FWD (Removal and Installation). * Parking brake control not fully released. * FREE UP and ADJUST the parking brake cable. REFER to: Parking Brake Cable Adjustment (206-05 Parking Brake and Actuation, General Procedures). INSTALL new components as necessary. * Malfunctioning anti-lock braking system (ABS). * REFER to: Anti-Lock Control (206-09A Anti-Lock Control, Diagnosis and Testing). * Shorted indicator circuit. * REFER to: Instrument Panel Cluster (IPC) (413-01 Instrument Panel Cluster (IPC), Diagnosis and Testing). Vibration when the brakes are applied * Grease or fluid on the brake shoes or brake pads; glazed linings. * INSTALL new brake shoes or brake pads. REFER to: Brake Pads (206-03 Front Disc Brake, Removal and Installation), Brake Pads (206-04 Rear Disc Brake, Removal and Installation). * Worn or damaged brake shoes or brake pads. * INSTALL new brake shoes or brake pads. REFER to: Brake Pads (206-03 Front Disc Brake, Removal and Installation), Brake Pads (206-04 Rear Disc Brake, Removal and Installation). * Loose caliper mounting bolt(s). * TIGHTEN the caliper mounting bolt(s). * Damaged brake drum contact surface. * INSTALL a new brake drum. * Excessive brake disc thickness variation or brake disc runout. * REFER to: Brake Disc Runout Check (206-00 Brake System - General Information, General Procedures). * Wheels and tires. * CHECK the tires. BALANCE or INSTALL new tires as necessary. REFER to: Wheels and Tires (204-04 Wheels and Tires, Diagnosis and Testing). * Loose or missing wheel hub bolts. * TIGHTEN or INSTALL new wheel hub bolts as necessary. * Worn or damaged brake drums or brake discs. * INSTALL new brake drums or brake discs. REFER to: Brake Disc (206-03 Front Disc Brake, Removal and Installation), Brake Disc (206-04 Rear Disc Brake, Removal and Installation). Pedal goes down fast * Low brake fluid level. * FILL the reservoir. CHECK the brake and clutch system for leaks including brake fluid in the brake booster. * Leak in the hydraulic system. * REPAIR the leak. CHECK the entire hydraulic system. FILL and BLEED the brake system. REFER to: (206-00 Brake System - General Information) Brake System Bleeding (General Procedures), Brake System Pressure Bleeding (General Procedures). * Air in the system. * CHECK for leaks. BLEED the brake system. REFER to: (206-00 Brake System - General Information) Brake System Bleeding (General Procedures), Brake System Pressure Bleeding (General Procedures). * Brake disc “brake knock back” (Brake pads push the brake caliper piston back into the brake caliper. Caused by excessive brake disc lateral runout or loose wheel bearings.) * CARRY OUT a brake disc runout check. REFER to: Brake Disc Runout Check (206-00 Brake System - General Information, General Procedures). * Worn brake shoes or brake pads. * INSTALL new brake shoes or brake pads. REFER to: Brake Pads (206-03 Front Disc Brake, Removal and Installation), Brake Pads (206-04 Rear Disc Brake, Removal and Installation). * Worn brake master cylinder piston cups or scored cylinder bore. * GO to Pinpoint Test A. * Hydraulic control unit (HCU). * REFER to: Anti-Lock Control (206-09A Anti-Lock Control, Diagnosis and Testing). Pedal eases down slowly * Air in the system. * BLEED the brake system. REFER to: (206-00 Brake System - General Information) Brake System Bleeding (General Procedures), Brake System Pressure Bleeding (General Procedures). * Malfunctioning brake master cylinder. * Low engine vacuum (stationary). * GO to Pinpoint Test B. Pedal is low or feels spongy * Worn brake shoes or brake pads. * INSTALL new brake shoes or brake pads. REFER to: Brake Pads (206-03 Front Disc Brake, Removal and Installation), Brake Pads (206-04 Rear Disc Brake, Removal and Installation). * Air in the system. * CHECK for leaks. BLEED the brake system. REFER to: (206-00 Brake System - General Information) Brake System Bleeding (General Procedures), Brake System Pressure Bleeding (General Procedures). * Brake master cylinder. * CARRY OUT the Brake Master Cylinder - Bypass Condition Test in this procedure. Brake lockup during light brake pedal force * Glazed or worn brake shoes or brake pads. * INSTALL new brake shoes or brake pads. REFER to: Brake Pads (206-03 Front Disc Brake, Removal and Installation), Brake Pads (206-04 Rear Disc Brake, Removal and Installation). * Hydraulic control unit (HCU). * REFER to: Anti-Lock Control (206-09A Anti-Lock Control, Diagnosis and Testing). * Brake booster. * Low engine vacuum. * GO to Pinpoint Test C. Excessive or erratic pedal travel * Worn brake shoes or brake pads. * INSTALL new brake shoes or brake pads. REFER to: Brake Pads (206-03 Front Disc Brake, Removal and Installation), Brake Pads (206-04 Rear Disc Brake, Removal and Installation). * Hydraulic control unit (HCU). * REFER to: Anti-Lock Control (206-09A Anti-Lock Control, Diagnosis and Testing). * Wheel bearings * CARRY OUT a brake disc runout check. REFER to: Brake Disc Runout Check (206-00 Brake System - General Information, General Procedures). Brake drag * Incorrectly adjusted parking brake. * ADJUST the parking brake cable. REFER to: Parking Brake Cable Adjustment (206-05 Parking Brake and Actuation, General Procedures). * Brake booster. * REFER to the Brake Booster Operation Check in this procedure. * Seized wheel cylinder or brake caliper. * INSTALL a new wheel cylinder or brake caliper. REFER to: Brake Caliper (206-03 Front Disc Brake, Removal and Installation), Brake Caliper (206-04 Rear Disc Brake, Removal and Installation). * Seized brake caliper slide pins. * INSTALL a new brake caliper. REFER to: Brake Caliper (206-03 Front Disc Brake, Removal and Installation), Brake Caliper (206-04 Rear Disc Brake, Removal and Installation). * Seized parking brake cables. * INSTALL new parking brake cables. REFER to: Parking Brake Cable (206-05 Parking Brake and Actuation, Removal and Installation). * Stoplamp switch. * VERIFY correct installation of the stoplamp switch. REFER to: Stoplamp Switch (417-01 Exterior Lighting, Removal and Installation). * Brake master cylinder. * CARRY OUT the Brake Master Cylinder - Bypass Compensator Port Test in this procedure. * Hydraulic control unit (HCU). * REFER to: Anti-Lock Control (206-09A Anti-Lock Control, Diagnosis and Testing). Excessive brake pedal effort * Worn or contaminated brake shoes or brake pads. * INSTALL new brake shoes or brake pads. REFER to: Brake Pads (206-03 Front Disc Brake, Removal and Installation), Brake Pads (206-04 Rear Disc Brake, Removal and Installation). * Malfunctioning vacuum pump (diesel). * INSTALL a new brake vacuum pump. * Disconnected or damaged brake booster vacuum pipe. * CONNECT or INSTALL a new brake booster vacuum pipe as necessary. * Brake booster. * GO to Pinpoint Test D. Brake noise * Worn or damaged brake shoes or brake pads. * INSTALL new brake shoes or brake pads. REFER to: Brake Pads (206-03 Front Disc Brake, Removal and Installation), Brake Pads (206-04 Rear Disc Brake, Removal and Installation). * Worn or damaged brake drums or brake discs. * INSTALL new brake drums or brake discs. REFER to: Brake Disc (206-03 Front Disc Brake, Removal and Installation), Brake Disc (206-04 Rear Disc Brake, Removal and Installation). * Brake booster. * GO to Pinpoint Test E. Slow or incomplete brake pedal return * Brake booster. * Seized brake pedal pivot. * GO to Pinpoint Test F. Pinpoint Tests PINPOINT TEST A : PEDAL GOES DOWN FAST TEST CONDITIONS DETAILS/RESULTS/ACTIONS A1: PRESSURIZE THE SYSTEM 1 Pump the foot brake rapidly five times. Does the brake pedal height build up and then hold? Yes CHECK parking brake adjustment and ADJUST as necessary. REFER to: Parking Brake Cable Adjustment (206-05 Parking Brake and Actuation, General Procedures). If the condition still exists. BLEED the brake system. REFER to: (206-00 Brake System - General Information) Brake System Bleeding (General Procedures), Brake System Pressure Bleeding (General Procedures). TEST the system for normal operation. No GO to A2. A2: CHECK FOR BRAKE SYSTEM LEAKS 1 Check for external brake and clutch system leaks. Refer to Brake Master Cylinder Component Test in this procedure. Are any leaks present? Yes REPAIR as necessary. ADD fluid and BLEED the brake system. REFER to: (206-00 Brake System - General Information) Brake System Bleeding (General Procedures), Brake System Pressure Bleeding (General Procedures). TEST the system for normal operation. No GO to A3. A3: PERFORM A BRAKE MASTER CYLINDER BYPASS CONDITION TEST 1 Carry out a brake master cylinder bypass Condition Test. Refer to the Brake Master Cylinder Component Test in this procedure. Was a concern found? Yes INSTALL a new brake master cylinder. REFER to: (206-06 Hydraulic Brake Actuation) Brake Master Cylinder - Vehicles With: LHD FWD (Removal and Installation), Brake Master Cylinder - Vehicles With: LHD FWD (Removal and Installation). TEST the system for normal operation. No VERIFY the customer concern. PINPOINT TEST B : PEDAL EASES DOWN SLOWLY TEST CONDITIONS DETAILS/RESULTS/ACTIONS B1: CHECK THE BRAKE PEDAL OPERATION 1 Depress the brake pedal. Does the pedal ease down slowly? Yes GO to B2. No Refer to the Brake Master Cylinder Component Test in this procedure. B2: CHECK FOR BRAKE SYSTEM LEAKS 1 Check for external brake system leaks. Are any leaks present? Yes REPAIR as necessary. ADD fluid and BLEED the brake system. REFER to: (206-00 Brake System - General Information) Brake System Bleeding (General Procedures), Brake System Pressure Bleeding (General Procedures). TEST the system for normal operation. No GO to B3. B3: PERFORM A BRAKE MASTER CYLINDER BYPASS CONDITION TEST 1 Carry out a brake master cylinder bypass Condition Test. Refer to the Brake Master Cylinder Component Test in this procedure. Was a concern found? Yes INSTALL a new brake master cylinder. REFER to: (206-06 Hydraulic Brake Actuation) Brake Master Cylinder - Vehicles With: LHD FWD (Removal and Installation), Brake Master Cylinder - Vehicles With: LHD FWD (Removal and Installation). TEST the system for normal operation. No GO to B4. B4: CHECK THE BRAKE BOOSTER CHECK VALVE 1 Disconnect the brake booster check valve vacuum hose at the manifold. 2 Blow into the hose attached to the brake booster check valve. Does air pass through the valve? Yes INSTALL a new brake booster check valve. No GO to B5. B5: CHECK THE BRAKE BOOSTER CHECK VALVE VACUUM 1 Run the engine at idle. 2 Using a suitable vacuum gauge, check the vacuum pressure. Is the vacuum pressure above 40.5 kPa (0.4 bar) with the brake booster non-operational? Yes VERIFY the customer concern. No INSTALL a new brake booster check valve vacuum hose. TEST the system for normal operation. PINPOINT TEST C : BRAKE LOCK UP DURING LIGHT BRAKE PEDAL FORCE TEST CONDITIONS DETAILS/RESULTS/ACTIONS C1: CHECK THE BRAKE BOOSTER 1 Check the brake booster push rod alignment and pedal travel. Is the push rod and pedal travel OK? Yes TEST the brake pedal application. GO to Pinpoint Test D. No INSTALL a new brake booster. REFER to: Brake Booster - Vehicles With: LHD FWD (206-07 Power Brake Actuation, Removal and Installation). TEST the system for normal operation. PINPOINT TEST D : EXCESSIVE BRAKE PEDAL EFFORT TEST CONDITIONS DETAILS/RESULTS/ACTIONS D1: CHECK BRAKE APPLICATION 1 With the engine off, apply and release the brake pedal five times to deplete all vacuum from the brake booster. Apply the brake pedal, hold with light pressure. Start the engine. Does the brake pedal hold? Yes GO to D2. No GO to D3. D2: CHECK THE BRAKE BOOSTER FOR LEAKS 1 Run the engine at approximately 1000 rpm, release the accelerator pedal and turn the engine off. Wait 90 seconds and apply the brakes. Two or more brake applications should be power assisted. Does the brake booster work? Yes VERIFY the customer concern. No GO to D4. D3: CHECK THE BRAKE PEDAL LINKAGE 1 Disconnect the actuator rod from the pedal pin and fully depress the brake pedal. Did the pedal move freely? Yes VERIFY the customer concern. No INSTALL new brake pedal bushings. TEST the system for normal operation. D4: CHECK THE BRAKE BOOSTER CHECK VALVE 1 Disconnect the brake booster check valve vacuum hose at the manifold. 2 Blow into the hose attached to the brake booster check valve. Does air pass through the valve? Yes INSTALL a new brake booster check valve. REFER to: Brake Booster - Vehicles With: LHD FWD (206-07 Power Brake Actuation, Removal and Installation). TEST the system for normal operation. No GO to D5. D5: CHECK THE BRAKE BOOSTER CHECK VALVE VACUUM 1 Run the engine at idle. 2 Using a suitable vacuum gauge, check the vacuum pressure. Is the vacuum pressure above 40.5 kPa (0.4 bar) with the brake booster non-operational? Yes GO to D6. No INSTALL a new vacuum hose and fittings. TEST the system for normal operation. D6: CHECK THE BRAKE BOOSTER 1 Check the brake booster. REFER to the Brake Booster Operation Check in this procedure. Is the brake booster OK? Yes VERIFY the customer concern. No INSTALL a new brake booster. REFER to: Brake Booster - Vehicles With: LHD FWD (206-07 Power Brake Actuation, Removal and Installation). TEST the system for normal operation. PINPOINT TEST E : BRAKE NOISE TEST CONDITIONS DETAILS/RESULTS/ACTIONS E1: CHECK FOR PEDAL NOISE 1 Run the engine at idle for 10 seconds or longer. 2 Apply the brake pedal and listen for noise. 3 Compare results with a known good system. Was a noise present? Yes GO to E2. No VERIFY the customer concern. E2: CHECK THE BRAKE BOOSTER 1 Check the brake booster push rod alignment and travel. Is the push rod and pedal travel OK? Yes BLEED the brake system. REFER to: (206-00 Brake System - General Information) Brake System Bleeding (General Procedures), Brake System Pressure Bleeding (General Procedures). TEST the system for normal operation. No INSTALL a new brake booster. REFER to: Brake Booster - Vehicles With: LHD FWD (206-07 Power Brake Actuation, Removal and Installation). TEST the system for normal operation. PINPOINT TEST F : SLOW OR INCOMPLETE BRAKE PEDAL RETURN TEST CONDITIONS DETAILS/RESULTS/ACTIONS F1: CHECK FOR BRAKE PEDAL RETURN 1 Run the engine at approximately 1200 rpm whilst making several brake applications. 2 Pull the brake pedal upwards with approximately 44.5 N (10 lbs) force. 3 Release the brake pedal and measure the distance to the floor panel and note the reading. 4 Make a hard brake application. 5 Release the brake pedal and measure the distance to the floor panel and note the reading. 6 Compare the measurements. Did the brake pedal return to its original position? Yes VERIFY the customer concern. No GO to F2. F2: CHECK FOR BRAKE PEDAL BINDING 1 Check the brake pedal for free operation. Did the brake pedal operate freely? Yes INSTALL a new brake booster. REFER to: Brake Booster - Vehicles With: LHD FWD (206-07 Power Brake Actuation, Removal and Installation). TEST the system for normal operation. No INSTALL new brake pedal bushings. TEST the system for normal operation. Component Tests Hydraulic Leak Check NOTE: There is a common clutch and brake fluid reservoir, therefore it is possible that a clutch leak can lead to reduction in the reservoir level. It is possible that all evidence of fluid leakage may have washed off if the vehicle has been operated in rain or snow, as brake fluid is water-soluble. Refill the system, bleed then apply the brakes several times. Examine the system to verify that the reservoir fluid level is actually dropping. Locate and repair the external leak. If the fluid level drops and no external leak can be found, check for a brake master cylinder bore end seal leak. Brake System Check Brake Pedal Reserve Check Where a low brake pedal or the feel of a bottomed-out condition exists, check for brake pedal reserve. Operate the engine at idle with the transaxle in the NEUTRAL position. Apply the brake pedal lightly three or four times. Allow 15 seconds for the vacuum to replenish the brake booster. NOTE: This increased resistance may feel like something has bottomed out. Apply the brake pedal until it stops moving downward or an increased resistance to the pedal travel occurs. Hold the brake pedal in the applied position and raise the engine speed to approximately 2000 rpm. NOTE: The additional movement of the brake pedal is the result of the increased engine manifold vacuum which exerts more force on the brake booster during engine rundown. This means that additional stroke is available in the brake master cylinder and the brake system is not bottoming out. Release the accelerator pedal and observe that the brake pedal moves downward as the engine returns to idle speed. Brake Booster Functional Test Inspect all hoses and connections. All unused vacuum connectors should be capped. Hoses and their connections should be correctly secured and in good condition with no holes and no collapsed areas. Inspect the check valve on the brake booster for damage. Brake Booster Operation Check Check the hydraulic brake system for leaks or low fluid. With the transaxle in the NEUTRAL position, stop the engine and apply the parking brake. Apply the brake pedal several times to exhaust all the vacuum in the system. With the engine turned off and the vacuum in the system exhausted, apply the brake pedal and hold it down. Start the engine. If the vacuum system is operating, the brake pedal will tend to move downward under constant foot pressure. If no motion is felt, the vacuum booster system is not functioning. Remove the vacuum hose from the brake booster. Manifold vacuum should be available at the brake booster end of the hose with the engine at idle speed and the transaxle in the NEUTRAL position. Make sure that all unused vacuum outlets are correctly capped, hose connectors are correctly secured and vacuum hoses are in good condition. When it is established that manifold vacuum is available to the brake booster, connect the vacuum hose to the brake booster and repeat Step 3. If no downward movement of the brake pedal is felt, install a new brake booster. REFER to: Brake Booster - Vehicles With: LHD FWD (206-07 Power Brake Actuation, Removal and Installation). Operate the the engine a minimum of 10 seconds at approximately 1200 rpm. Stop the engine and let the vehicle stand for 10 minutes. Then, apply the brake pedal with approximately 89 N (20 lb) force. The pedal feel (brake application) should be the same as that noted with the engine operating. If the brake pedal feels hard (no power assist), install a new vacuum check valve and then repeat the test. If the brake pedal still feels hard, install a new brake booster. REFER to: Brake Booster - Vehicles With: LHD FWD (206-07 Power Brake Actuation, Removal and Installation). If the brake pedal movement feels spongy, bleed the brake system. REFER to: (206-00 Brake System - General Information) Brake System Bleeding (General Procedures), Brake System Pressure Bleeding (General Procedures). Brake Master Cylinder Usually, the first and strongest indicator of anything wrong with the braking system is a feeling through the brake pedal. In diagnosing the condition of the brake master cylinder, check pedal feel as evidence of a brake concern. Check for the red brake warning indicator illumination and the fluid level in the master cylinder reservoir. Normal Conditions The following conditions are considered normal and are not indications that the brake master cylinder is in need of service. Modern brake systems are not designed to produce as hard a pedal effort as in the past. Complaints of light pedal efforts should be compared to pedal efforts of another vehicle, of the same model and year. During normal operation of the brake pedal, the fluid level in the reservoir will rise during brake pedal application and fall during release. The net fluid level (i.e., after brake pedal application and release) will remain unchanged. A trace of brake fluid will exists on the brake booster shell below the master cylinder mounting flange. This results from the normal lubricating action of the master cylinder bore end seal. The fluid level will fall with brake shoe and lining wear. Abnormal Conditions NOTE: Prior to performing any diagnosis, make sure the brake system warning indicator is functional. Changes in brake pedal feel or travel are indicators that something could be wrong with the braking system. The diagnostic procedure and techniques use brake pedal feel, warning indicator illumination and low brake fluid level as indicators in diagnosing braking system concerns. The following conditions are considered abnormal and indicate that the brake master cylinder is in need of service. The brake pedal goes down fast. This could be caused by an external or internal leak. The brake pedal eases down slowly. This could be caused by an external or internal leak. The brake pedal is low and or feels spongy. This condition may be caused by no fluid in the brake master cylinder reservoir, reservoir cap vent holes clogged or air in the hydraulic system. The brake pedal effort is excessive. This may be caused by a bind or obstruction in the pedal or linkage, clogged fluid control valve or insufficient booster vacuum. The rear brakes lock up during light pedal force. This may be caused by incorrect tire pressures, grease or fluid on the brake shoes and linings, damaged brake shoes and linings, incorrectly adjusted parking brake, or damaged or contaminated brake pressure control valves. The brake pedal effort is erratic. This condition could be caused by a brake booster malfunction, extreme caliper piston knock back or incorrectly installed brake shoes and linings. The red brake warning indicator is ON. This may be caused by low fluid level, ignition wire routing too close to the fluid level indicator assembly, or float assembly damage. Brake Master Cylinder - Compensator Port Test Inspect the master cylinder. Raise and support the vehicle. REFER to: Lifting (100-02 Jacking and Lifting, Description and Operation). Apply and release the brakes. With the brakes released, attempt to rotate each wheel and check for any brake drag. If an excessive amount of brake drag exists at multiple wheels, continue to the next step. If an excessive amount of brake drag exists at only one wheel, it indicates a possible seized brake caliper, brake wheel cylinder or parking brake component. Repair or install new components as necessary. Check the brake stoplamp switch and the brake pedal free play to verify the brake pedal is not partially applied. Loosen the brake master cylinder nuts and position the brake master cylinder away from the brake booster. With the brakes released, attempt to rotate each wheel and check for any brake drag. If the brake drag is no longer present, install a new brake booster. REFER to: Brake Booster - Vehicles With: LHD FWD (206-07 Power Brake Actuation, Removal and Installation). If the brake drag is still present, install a new master cylinder. REFER to: Brake Master Cylinder - Vehicles With: LHD FWD (206-06 Hydraulic Brake Actuation, Removal and Installation). Brake Master Cylinder - Bypass Condition Test Check the fluid in the brake master cylinder reservoir. Fill the brake master cylinder reservoir if low or empty. Observe the fluid level in the brake master cylinder reservoir. If after several brake applications, the fluid level remains the same, measure the wheel turning torque required to rotate the wheels with the brakes applied as follows: Place the transaxle in the NEUTRAL position. Raise and support the vehicle. REFER to: Lifting (100-02 Jacking and Lifting, Description and Operation). Apply the brakes with a minimum of 445 N (100 lb) and hold for approximately 15 seconds. With the brakes still applied, exert a torque on the front wheels of 10.1 Nm (75 lb ft). If either wheel rotates, install a new brake master cylinder. REFER to: Brake Booster - Vehicles With: LHD FWD (206-07 Power Brake Actuation, Removal and Installation). Non-Pressure Leaks Any empty brake master cylinder reservoir condition may be caused by two types of non-pressure external leaks. Type 1: An external leak may occur at the brake master cylinder reservoir cap because of incorrect positioning of the gasket and cap. Reposition the cap and gasket. Type 2: An external leak may occur at the brake master cylinder reservoir mounting seals. Service such a leak by installing new seals.