Antilock Brake System and Traction Control System Buick Rendezvous I

Fastener Tightening Specifications

Fastener Tightening Specifications

Scheme 1

Scheme 2

Scheme 3

Scheme 4

Scheme 5

Scheme 6

ABS Connector End Views

Electronic Brake Control Module (EBCM) Connector End Connector Part Information 15326390 30-Way F GT 150 280 SEALED 4.0 5.8 (BLK) Pin Wire Color Circuit No. Function 1 - - Not Used 2 BRN 882 Right Rear Wheel Speed Sensor Signal 3 WHT 883 Right Rear Wheel Speed Sensor Low Reference 4 DK GRN 872 Right Front Wheel Speed Sensor Signal 5 TAN 833 Right Front Wheel Speed Sensor Low Reference 6 WHT 17 Stop Lamp Switch Signal 7 - - Not Used 8 PNK 1039 Ignition 1 Voltage 9 TAN/BLK 464 Delivered Torque Signal 10 - - Not Used 11 WHT 121 Engine Speed Signal (W/NW9) 12 BLK/WHT 251 Ground 13 RED 1442 Battery Positive Voltage 14 ORN 1740 Battery Positive Voltage 15 BLK/WHT 251 Ground 16-19 - - Not Used 20 LT BLU 830 Left Front Wheel Speed Sensor Signal 21 YEL 873 Left Front Wheel Speed Sensor Low Reference 22 BLK 884 Left Rear Wheel Speed Sensor Signal 23 RED 885 Left Rear Wheel Speed Sensor Low Reference 24 - - Not Used 25 LT BLU 1122 ABS/TCS Class 2 Serial Data 26 - - Not Used 27 ORN/BLK 463 Requested Torque Signal 28-30 - - Not Used

I/P Switch Assembly Connector End - C1 (Pontiac) Connector Part Information 12162455 8-Way F 280 Series (NAT) Pin Wire Color Circuit No. Function A GRY 8 Instrument Panel Lamp Supply Voltage B BLK 150 Ground C WHT/BLK 1221 Lift Gate Release Switch Signal D BRN/WHT 1571 Traction Control Switch Signal E-H - - Not Used

Wheel Speed Sensor Connector End - LF Connector Part Information 12052644 2-Way F Metri-Pack 150 Series Sealed (WHT) Pin Wire Color Circuit No. Function A YEL 873 Left Front Wheel Speed Sensor Low Reference B LT BLU 830 Left Front Wheel Speed Sensor Signal

Wheel Speed Sensor Connector End - LR Connector Part Information 12052644 2-Way F Metri-Pack 150 Series Sealed (WHT) Pin Wire Color Circuit No. Function A WHT 883 Right Rear Wheel Speed Sensor Low Reference B BLK 882 Right Rear Wheel Speed Sensor Signal

Wheel Speed Sensor Connector End - RF Connector Part Information 12052644 2-Way F Metri-Pack 150 Series Sealed (WHT) Pin Wire Color Circuit No. Function A DK GRN 872 Right Front Wheel Speed Sensor Signal B TAN 833 Right Front Wheel Speed Sensor Low Reference

Wheel Speed Sensor Connector End - RR Connector Part Information 12052644 2-Way F Metri-Pack 150 Series Sealed (WHT) Pin Wire Color Circuit No. Function A WHT 883 Right Rear Wheel Speed Sensor Low Reference B BLK 882 Right Rear Wheel Speed Sensor Signal

Diagnostic Starting Point - Antilock Brake System

Begin the system diagnosis with Diagnostic System Check - ABS . The Diagnostic System Check will provide the following information

1. The identification of the control modules which command the system
2. The ability of the control modules to communicate through the serial data circuit
3. The identification of any stored diagnostic trouble codes (DTCs) and their status

The use of the Diagnostic System Check will identify the correct procedure for diagnosing the system and where the procedure is located.

Circuit Description

The ABS Diagnostic System Check is an organized approach to identify problems associated with the EBCM. This check must be the starting point for any EBCM complaint, and will direct you to the next logical step in diagnosing the complaint. The EBCM is a very reliable component and is not likely the cause of the malfunction. Most system complaints are linked to faulty wiring, connectors, and occasionally to components. Understanding the ABS system and using the tables correctly will reduce diagnostic time and prevent unnecessary parts replacement.

Diagnostic System Check - ABS

Scan Tool Output Controls

Scan Tool Output Controls

Scan Tool Data List

The EBCM Scan Tool Data Lists contain all the antilock brake system related parameters that are available on the scan tool. The parameters in the list are arranged in alphabetical order. The column, 'Data List,' indicates the location of the parameter within the scan tool menu selections.

Use the EBCM Scan Tool Data Lists as directed by a diagnostic table or in order to supplement the diagnostic procedures. Begin all the diagnostic procedures with the ABS Diagnostic Starting Point. Use the EBCM Scan Tool Data Lists only after the following is determined

1. There is no published DTC procedure nor published symptom procedure for the customer concern. or
2. The DTC or symptom diagnostic procedure indicated by the diagnostic system check does not resolve the customer concern.

The Typical Data Values are obtained from a properly operating vehicle under the conditions specified in the first row of the Scan Tool Data List table. Comparison of the parameter values from the suspect vehicle with the Typical Data Values may reveal the source of the customer concern.

The ID Information menu is located on the EBCM main screen.

EBCM Scan Tool Data List

Data Display/Definitions

The Scan Tool Data Display/Definitions contains a brief description of all the ABS/ TCS/VSES data parameters. The menus available depend on the number and type of system on the vehicle and are listed below in alphanumeric order.

1. ABS DATA
2. TCS DATA

Diagnostic Trouble Code (DTC) List

Diagnostic Trouble Code (DTC) List

Diagnostic Test Drive

When servicing vehicles, the vehicle antilock brake and traction control system, test drives will be necessary to allow all tests to be run, and all system functions to be enabled and exercised. A test drive may also be required to duplicate specific DTCs covered in this section. The diagnostic system check (including test drive) should be run when vehicle repairs are complete in order to verify the repair.

The diagnostic test drive will vary for ABS/TCS problems.

1. Read the Diagnostic Aids and the Conditions for Setting the DTC.
2. Reconnect any previously disconnected components.
3. Start the engine.
4. Drive the vehicle under the following conditions for at least 10 minutes. At no times should any unlawful or unsafe maneuvers be performed. Highway driving. Rough roads. Verify customers concern and duplicate driving conditions. With the engine still running use the scan tool and check for any DTCs. If any DTCs are set, perform the appropriate DTC table.

History Data

Enhanced diagnostic information is found in the History Data function of the scan tool. Enhanced diagnostic information provides the service technician with specific malfunction occurrence information.

The scan tool will display the last 3 DTCs to occur, one at a time. The DTC with the most recent occurrence will be displayed first. Each DTC will include the following

1. The number of drive cycles since the DTC last occurred.
2. The number of occurrences for the DTC since the scan tool DTC information was last cleared.

The most recent DTC will also display various data parameters with values from the time of the DTC occurrence.

Diagnostic Strategy

In difficult diagnostic situations use the above information to identify malfunction occurrence trends. Ask question such as the following

1. Did the malfunction only occur once over a large number of drive cycles, indicating an unusual condition present when it occurred?
2. Does the malfunction occur infrequently over a large number of drive cycles, indicating that special diagnostic techniques may be required to identify the source of the malfunction?

A malfunction that occurs more frequently increases the odds of finding the cause of the malfunction.

Use the information in order to determine if a DTC is intermittent. Use the information in order to determine if the DTC has not set for long periods of time due to weather changes or a repair prior to this visit.

The traction control switch is a momentary switch. The signal circuit of the traction control switch is grounded when the driver presses the traction control switch. The traction control system will change state from traction on to traction off or from traction off to traction on each time the traction control switch is pressed.

Conditions for Running the DTC

1. The battery voltage is between 9.0 volts and 16.0 volts.
2. The park brake is not applied.

Conditions for Setting the DTC

1. The signal circuit voltage of the traction control switch is no more than 2.0 volts.
2. All of the above conditions are present for greater than 60 seconds.

Action Taken When the DTC Sets

If equipped, the following actions occur

1. The BCM stores DTC B2747 in memory.
2. The traction control switch input is ignored until the fault is no longer current.

Conditions for Clearing the DTC

1. A current DTC B2747 will clear if the BCM no longer detects a short to ground for longer than 60 seconds.
2. A history DTC B2747 will clear after 100 consecutive ignition cycles if the condition for the malfunction is no longer present.
3. A scan tool may be used to clear the DTC.

Diagnostic Aids

Check for a traction control switch that may be sticking in the pressed position. For an intermittent condition refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

Test Description

The numbers below refer to the step numbers on the diagnostic table.

1. 2: This step verifies that the fault is present.
2. 3: This step tests for a shorted switch.

DTC B2747

As the wheel spins, the wheel speed sensor produces an AC signal. The electronic brake control module (EBCM) uses the frequency of the AC signal to calculate the wheel speed.

C0035 C0040 C0045 C0050

The ignition is ON.

C0036 C0041 C0046 C0051

1. Vehicle speed is over 40 km/h (25 mph).
2. The brake pedal is not pressed.
3. The ABS is not active.

One of the following conditions exists for 0.02 seconds

1. A short to voltage - in the wheel speed sensor signal circuit.
2. An open - in the wheel speed sensor signal circuit.

All of the following conditions exists for 0.01 seconds

1. The suspect wheel speed equals zero.
2. The other wheel speeds are greater than 40 km/h (25 mph) for 0.01 seconds.
3. The suspect wheel equals zero during drive off, and the other wheels are greater than 18 km/h (11 mph).
4. A short to ground - the wheel speed sensor signal circuit is shorted to ground.
5. A deviation of two wheel speeds at either side of the vehicle greater than 6 km/h (4 mph), or at the front axle greater than 10 km/h (6 mph) for a time period of 10 to 20 seconds.

If equipped, the following actions occur

1. The EBCM disables the ABS/TCS for the duration of the ignition cycle.
2. A DTC malfunction will set.
3. The ANTI-LOCK indicator turns ON.
4. The TRAC Off indicator turns ON.
5. The Red BRAKE Warning indicator could turn on.
6. The AWD disable indicator could turn on if equipped.

1. The condition for the DTC is no longer present and the DTC is cleared with a scan tool.
2. The electronic brake control module (EBCM) automatically clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles.

If the customer comments that the ABS indicator is ON only during moist environmental conditions (rain, snow, vehicle wash, etc.), inspect the wheel speed sensor wiring for signs of water intrusion. If the DTC is not current, clear all DTCs and simulate the effects of water intrusion by using the following procedure

1. Spray the suspected area with a 5 percent saltwater solution. To create a 5 percent saltwater solution, add 2 teaspoons of salt to 354 ml (12 oz) of water.
2. Test drive the vehicle over various road surfaces (bumps, turns, etc.) above 40 km/h (25 mph) for at least 30 seconds.
3. If the DTC returns, replace the suspected wheel speed sensor or repair the wheel speed sensor wiring.
4. Rinse the area thoroughly when completed.

Under the following conditions, 2 Wheel Speed Sensor Input is 0 DTCs are set

1. The 2 suspect wheel speeds equal zero for 10-20 seconds.
2. The other wheel speeds are greater than 16 km/h (10 mph).
3. The other wheel speeds are within 11 km/h (7 mph) of each other.

Diagnose each wheel speed sensor individually.

A possible cause of this DTC is electrical noise on the wheel speed sensor harness wiring. Electrical noise could result from the wheel speed sensor wires being routed too close to high energy ignition system components, such as spark plug wires.

The numbers below refer to the step numbers on the diagnostic table.

1. 3: This step tests the wheel speed sensor for the proper resistance value.
2. 4: This step ensures that the wheel speed sensor generates the proper voltage.

DTC C0035-C0051

The inlet and outlet valve solenoid circuits are supplied with battery power when the ignition is in the ON position. The EBCM controls the valve functions by grounding the circuit when necessary.

1. The DTC can set anytime the ignition switch is in the ON position.
2. The DTC can set when the vehicle speed is greater then 6 km/h (4 mph) and the brake pedal is not applied.
3. The DTC can set when the vehicle speed is greater then 15 km/h (9 mph) and the brake pedal is applied.

The DTC will set when the EBCM detects one of the following internal to the EBCM only

1. An open in the solenoid coil or circuit.
2. A short to ground in the solenoid coil or circuit.
3. A short to voltage in the solenoid coil or circuit.

If equipped, the following actions occur

1. The EBCM disables the ABS/TCS/DRP for the duration of the ignition cycle.
2. A malfunction DTC will set.
3. The ANTI-LOCK indicator turns ON.
4. The TRAC Off indicator turns ON.
5. The Red BRAKE Warning indicator could turn on.

1. The condition for the DTC is no longer present and the DTC is cleared with a scan tool.
2. The electronic brake control module (EBCM) automatically clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles.

The solenoid valve circuit and the solenoid coil are internal to the EBCM. No part of the solenoid circuit is diagnosable external to the EBCM. The DTC sets when there is a malfunction in the solenoid circuit internal to the EBCM only.

The numbers below refer to step numbers on the Diagnostic Table.

1. 2: This step determines if the DTC is current.

DTC C0060-C0095

The pump motor is an integral part of the BPMV, while the pump motor relay is integral to the EBCM. The pump motor relay is not engaged during normal system operation. When ABS or TCS operation is required the EBCM activates the pump motor relay and battery power is provided to the pump motor.

1. The ignition switch is in the ON position.
2. Initialization is complete.

1. Pump motor voltage is not present 60 milliseconds after activation of the pump motor relay.
2. Pump motor voltage is present for more than 2.5 seconds with no activation of the pump motor relay.
3. Pump motor voltage is not present for 40 milliseconds after the pump motor relay is commanded off.

If equipped, the following actions occur

1. The EBCM disables the ABS/TCS for the duration of the ignition cycle.
2. A malfunction DTC will set.
3. The ANTI-LOCK indicator turns ON.
4. The TRAC Off indicator turns ON.
5. The Red BRAKE Warning indicator could turn on.

1. The condition for the DTC is no longer present and the DTC is cleared with a scan tool.
2. The electronic brake control module (EBCM) automatically clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles.

1. It is very important that a thorough inspection of the wiring and connectors be performed. Failure to carefully and fully inspect wiring and connectors may result in misdiagnosis, causing part replacement with reappearance of the malfunction.
2. Thoroughly inspect any circuitry that may be causing the complaint for the following conditions: Backed out terminals Improper mating Broken locks Improperly formed or damaged terminals Poor terminal-to-wiring connections Physical damage to the wiring harness
3. The following conditions may cause an intermittent malfunction: A poor connection Rubbed-through wire insulation A broken wire inside the insulation
4. If an intermittent malfunction exists refer to «Testing for Intermittent Conditions and Poor Connections»(/buick/rendezvous/i-2001-2007/remont/body-electrical/#wiring-systems-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor) in Wiring Systems.

The number below refers to the step number on the diagnostic table.

1. 3: Tests the pump motor circuits of the BPMV for a short to the housing of the BPMV. The wiring from the BPMV to the EBCM should not be repaired.

DTC C0110

The solenoid valve relay supplies power to the solenoid valve coils in the EBCM. The solenoid valve relay, located in the EBCM, is activated whenever the ignition switch is in the RUN position and no faults are present. The solenoid valve relay remains engaged until the ignition is turned OFF or a failure is detected.

The ignition switch is in the ON position.

1. DTC C0121 will set anytime the solenoid valve relay is commanded on and the EBCM does not see battery voltage at the solenoid valves.
2. DTC C0121 will set anytime the EBCM commands the solenoid valve relay off and battery voltage is still present at the solenoid valves.

If equipped, the following actions occur

1. The EBCM disables the ABS/TCS/DRP for the duration of the ignition cycle.
2. A malfunction DTC is set.
3. The ANTI-LOCK indicator turns ON.
4. The TRAC Off indicator turns ON.
5. The Red BRAKE Warning indicator could turn on.

1. The condition for the DTC is no longer present and the DTC is cleared with a scan tool.
2. The electronic brake control module (EBCM) automatically clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles.

1. It is very important that a thorough inspection of the wiring and connectors be performed. Failure to carefully and fully inspect wiring and connectors may result in misdiagnosis, causing part replacement with reappearance of the malfunction.
2. Thoroughly inspect any circuitry that may be causing the complaint for the following conditions: Backed out terminals Improper mating Broken locks Improperly formed or damaged terminals Poor terminal-to-wiring connections Physical damage to the wiring harness
3. The following conditions may cause an intermittent malfunction: A poor connection Rubbed-through wire insulation A broken wire inside the insulation
4. If an intermittent malfunction exists, refer to «Testing for Intermittent Conditions and Poor Connections»(/buick/rendezvous/i-2001-2007/remont/body-electrical/#wiring-systems-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor) in Wiring Systems.
5. The solenoid valve relay is an integral part of the EBCM and is not serviced separately.

The number below refers to step number on the Diagnostic Table.

1. 2: This step determines if the DTC is current.

DTC C0121

The isolation and prime valve solenoid circuits are supplied with battery power when the ignition is in the ON position. The EBCM controls the valve functions by grounding the circuit when necessary.

1. The ignition switch is in the ON position.
2. The DTC can be set after system initialization.

The DTC will set when the EBCM detects one of the following internal to the EBCM only

1. An open in the solenoid coil or circuit.
2. A short to ground in the solenoid coil or circuit.
3. A short to voltage in the solenoid coil or circuit.

If equipped, the following actions occur

1. The EBCM disables the ABS/TCS/DRP for the duration of the ignition cycle.
2. A malfunction DTC is set.
3. The ANTI-LOCK indicator turns ON.
4. The TRAC Off indicator turns ON.
5. The Red BRAKE Warning indicator could turn on.

1. Condition for DTC is no longer present and scan tool clear DTC function is used.
2. 100 ignition cycles pass with no DTC(s) detected.

The solenoid valve circuit and the solenoid coil are internal to the EBCM. No part of the solenoid circuit is diagnosable external to the EBCM. The DTC sets when there is a malfunction in the solenoid circuit internal to the EBCM only.

The numbers below refer to step numbers on the Diagnostic Table.

1. 2: This step determines if the DTC is current.

DTC C0141-C0156

The Stoplamp Switch is a normally open switch, when the brake pedal is depressed the EBCM will sense battery voltage. This allows the EBCM to determine the state of the brake lamps. The EBCM sources 5 volts on the stop lamp switch signal circuit when the stop lamp switch is inactive. The voltage is supplied a ground path through the stop lamp bulbs.

The ignition switch is ON.

1. EBCM detects open in the brake signal circuit.
2. Both brake lamps are faulty.
3. The stoplamp switch input voltage is between 6.6 and 9 volts for 0.5 second.

If equipped, the following actions occur

1. A malfunction DTC will set.
2. The EBCM stores this information-only DTC for as long as the condition is present.
3. The ABS remains functional.
4. The ABS indicator remains OFF.

1. The condition for the DTC is no longer present and the DTC is cleared with a scan tool.
2. The electronic brake control module (EBCM) automatically clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles.

1. It is very important that a thorough inspection of the wiring and connectors be performed. Failure to carefully and fully inspect wiring and connectors may result in misdiagnosis, causing part replacement with reappearance of the malfunction.
2. Thoroughly inspect any circuitry that may be causing the complaint for the following conditions: Backed out terminals Improper mating Broken locks Improperly formed or damaged terminals Poor terminal-to-wiring connections Physical damage to the wiring harness
3. Possible causes of this DTC are the following conditions: A signal circuit of the stop lamp switch is open The stop lamp switch is misadjusted Verify proper stop lamp switch operation using the data list of the scan tool. As the brake is applied, the data list displays the stop lamp switch ON within 2.54 cm (1 in) of travel All brake lamps are open All brake lamp grounds are open Circuit has a wiring problem, terminal corrosion, or poor connections Loose or corroded EBCM ground
4. If an intermittent malfunction exists refer to «Testing for Intermittent Conditions and Poor Connections»(/buick/rendezvous/i-2001-2007/remont/body-electrical/#wiring-systems-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor) in Wiring Systems.

The numbers below refer to the step numbers on the diagnostic table.

1. 3: This DTC detects an open stop lamp switch signal circuit from the stop lamp side of the splice pack to the EBCM.
2. 4: The EBCM sources 5 volts on the stop lamp switch signal circuit. This small voltage has a ground path through the stop lamp bulbs. This DTC sets if the path to ground is open.

DTC C0161

The RPM signal circuit provides the EBCM with an indication of engine RPM to help determine TCS control methods and rates when a TCS event takes place.

1. The ignition switch is ON and the engine running.
2. After 2 seconds starting, and if there is a undervoltage condition.

The EBCM does not received an RPM input signal after 1 second, after the engine has been started.

If equipped, the following actions occur

1. A malfunction DTC is stored.
2. The TRAC OFF indicator is turned on.
3. The TCS is disabled. ABS remains functional.

1. The condition for DTC is no longer present and the scan tool Clear DTCs function is used.
2. 100 ignition cycles have passed with no DTC(s) detected.

Perform a thorough inspection of the wiring. Perform a thorough inspection of the connectors. Failure to carefully and fully inspect the wiring and the connectors may result in misdiagnosis. Misdiagnosis causes part replacement with reappearance of the malfunction.

The number(s) below refer to the step number(s) on the diagnostic table.

1. 2: If the instrument panel tachometer is working properly, the cause of the malfunction is most likely between the PCM and the EBCM, or the EBCM itself.
2. 9: At this point, the PCM is likely causing the malfunction. Refer to the OBD system check.

DTC C0236

The PCM monitors various parameters and will not allow traction control operation if any parameter falls below a specified value.

The ignition is ON.

The PCM detects a malfunction and then causes TCS shut down until the malfunction has been corrected.

If equipped, the following actions occur

1. A DTC C0240 is stored.
2. The TCS is disabled.
3. The TRAC OFF indicator is turned on.
4. If the TCS is again allowed to function, the indicator will be turned off but the DTC will be stored.

1. The condition for the DTC is no longer present and the DTC is cleared with a scan tool.
2. The electronic brake control module (EBCM) automatically clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles.

The numbers below refer to the step numbers on the diagnostic table.

1. 4: This step checks if DTC C0240 resets.

DTC C0240

The EBCM and the PCM simultaneously control the traction control. The EBCM sends a Requested Torque message via a pulse width modulated (PWM) signal to the PCM. The duty cycle of the signal is used to determine how much engine torque the EBCM is requesting the PCM to deliver. Normal values are between 10 and 90 percent duty cycle. The signal should be at 90 percent when traction control is not active and at lower values during traction control activations. The PCM supplies the pull up voltage that the EBCM switches to ground to create the signal.

The ignition is ON.

The PCM diagnoses the requested torque PWM signal circuit and sends a class 2 serial data message to the EBCM indicating a fault is present. A fault exists in the circuit if the PCM detects one of the following conditions

1. The requested torque PWM signal is less than 5 percent duty cycle or greater than 95 percent duty cycle.
2. The requested torque PWM signal is not present for 10 seconds.

If equipped, the following actions occur

1. The EBCM disables the traction control system (TCS)/VSES for the duration of the ignition cycle.
2. A malfunction DTC will set.
3. The Stability OFF indicator turns ON.
4. The antilock brake system (ABS) remains functional.

1. The condition for the DTC is no longer present (the DTC is not current) and you used the scan tool Clear DTC function.
2. The EBCM automatically clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles.

The numbers below refer to the step numbers on the diagnostic table.

1. 3: Use the scan tool in order to determine if the requested torque signal has a valid duty cycle.
2. 4: Measure the requested torque signal in order to determine if the signal has a valid duty cycle.
3. 5: Measure the requested torque signal in order to determine if the signal has a valid frequency.
4. 11: This vehicle is equipped with a PCM which uses an electrically erasable programmable read only memory (EEPROM). When replacing the PCM, the replacement PCM must be programmed.

DTC C0241 or P0856

Traction Control is simultaneously controlled by the EBCM and the PCM. The PCM sends a DELIVERED TORQUE message via a Pulse Width Modulated (PWM) signal to the EBCM confirming the delivered torque level for proper Traction Control system operation. The EBCM supplies the pull up voltage.

1. The ignition switch is ON.
2. The DTC can be set after system initialization.

DTC C0244 can be set anytime when ignition voltage is present. A malfunction exists if the PWM signal is out of range or no signal is received for a period of 2 seconds.

If equipped, the following actions occur

1. A malfunction DTC is stored.
2. The TCS is disabled.
3. The TRAC OFF indicator is turned on. The ABS remains functional.

1. The condition for the DTC is no longer present and the DTC is cleared with a scan tool.
2. The electronic brake control module (EBCM) automatically clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles.

1. It is very important that a thorough inspection of the wiring and connectors be performed. Failure to carefully and fully inspect wiring and connectors may result in misdiagnosis, causing part replacement with reappearance of the malfunction.
2. If an intermittent malfunction exists refer to «Checking Aftermarket Accessories»(/buick/rendezvous/i-2001-2007/remont/body-electrical/#wiring-systems-diagnostic-information-and-procedures__checking-aftermarket-accessories) in Wiring Systems.
3. Possible causes for DTC C0244 to set: Open in the Torque Delivered Control circuit. Torque Delivered Control circuit shorted to ground or voltage. Communication frequency problem. Communication duty cycle problem. Torque Delivered Control circuit has a wiring problem, terminal corrosion, or poor connections. EBCM not receiving information from the PCM.

The numbers below refer to the step numbers on the diagnostic table.

1. 3: Use the scan tool in order to determine if the delivered torque signal has a valid duty cycle.
2. 9: This vehicle is equipped with a PCM which uses an Electrically Erasable Programmable Read Only Memory (EEPROM). When replacing the PCM, the replacement PCM must be programmed.

DTC C0244 or P1689

The speed sensors used on the front of this vehicle are multiple pole and the rear uses a single pole magnetic pickup. This sensor produces an AC signal that the EBCM uses the frequency from to calculate the wheel speed.

1. The ignition switch is ON.
2. The DTC can be set after system initialization.

1. The EBCM detects a deviation between the left and right rear wheel speeds of greater than 6 km/h (3.75 mph) at a vehicle speed of less than 100 km/h (62 mph) on vehicles equipped with TCS.
2. The EBCM detects a deviation between the left and right front wheel speeds of greater than 10 km/h (6.25 mph) at a vehicle speed of less than 100 km/h (62 mph).
3. The EBCM detects a deviation between the left and right rear wheel speeds of greater than 6 percent of the vehicle speed at greater than 100 km/h (62 mph) on vehicles equipped with TCS.
4. The EBCM detects a deviation between the left and right front wheel speeds of greater than 4 km/h plus 6 percent of the vehicle speed at greater than 100 km/h (62 mph).

This DTC will set when the EBCM cannot specifically identify which wheel speed sensor is causing the malfunction. If the EBCM can identify the specific wheel speed sensor causing the malfunction, DTC C0245 will become a history DTC, and the DTC associated with the sensor (DTC C0036, DTC C0041, DTC C0046, DTC C0051, or DTC C0056) will be set concurrent with DTC C0245.

If equipped, the following actions occur

1. A malfunction DTC stores.
2. The ABS/TCS disables.
3. The amber ABS/TCS indicator(s) turn on.
4. The Red BRAKE Warning indicator turn on.

1. The condition for the DTC is no longer present and the DTC is cleared with a scan tool.
2. The electronic brake control module (EBCM) automatically clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles.

1. It is very important that a thorough inspection of the wiring and connectors be performed. Failure to carefully and fully inspect wiring and connectors may result in misdiagnosis, causing part replacement with reappearance of the malfunction.
2. Thoroughly inspect any circuitry that may be causing the complaint for the following conditions: Backed out terminals Improper mating Broken locks Improperly formed or damaged terminals Poor terminal-to-wiring connections Physical damage to the wiring harness
3. The following conditions may cause an intermittent malfunction: A poor connection Rubbed-through wire insulation A broken wire inside the insulation
4. If the customer's comments reflect that the amber ABS/TCS indicator is on only during moist environmental conditions (rain, snow, vehicle wash), inspect all the wheel speed sensor circuitry for signs of water intrusion. If the DTC is not current, clear all DTCs and simulate the effects of water intrusion by using the following procedure: Spray the suspected area with a five percent saltwater solution. Add two teaspoons of salt to twelve ounces of water to make a five percent saltwater solution. Test drive the vehicle over various road surfaces (bumps, turns, etc.) above 40 km/h (25 mph) for at least 30 seconds. If the DTC returns, replace the suspected harness.
5. If an intermittent malfunction exists refer to «Testing for Intermittent Conditions and Poor Connections»(/buick/rendezvous/i-2001-2007/remont/body-electrical/#wiring-systems-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor) in Wiring Systems.

The numbers below refer to step numbers on the diagnostic table.

1. 2: If DTC C0245 is a history code, this step checks if a specific Wheel Speed Circuit Malfunction DTC is set concurrently with DTC C0245.
2. 7: This step checks if the wheel speed sensor harness is routed in close proximity to the spark plug wires.
3. 9: In this step, if the scan tool can record any erroneous wheel speed sensor signals, diagnose that sensor(s) first.

DTC C0245

The EBCM learns the model that it is installed in by using the Vehicle ID information (VIN) via the class 2 serial data line. Each time the vehicle is in the RUN position or the PCM communicates this information via Class 2, the EBCM internally compares the VIN information with that information stored in digits 2 through 5 of the VIN. If digit 5 of the VIN is incorrect, the EBCM will indicate a VIN information error is present.

1. The EBCM detects digit 5 of the VIN is incorrect.
2. The condition must occur when the ignition switch is first turned on.

The EBCM stores DTC C0565 in memory.

1. The EBCM recognizes digit 5 of the VIN as valid information.
2. A history DTC will clear after 100 consecutive ignition cycles if the condition for the malfunction is no longer present.

DTC C0565 is related to an internal VIN error in the EBCM. The VIN information is not removable from the EBCM.

DTC C0565

The EBCM is required to operate within a specified range of voltage to function properly. During ABS and TCS operation, there are current requirements that will cause the voltage to drop. Because of this, voltage is monitored out of ABS/TCS control to indicate a good charging system condition, and also during ABS/TCS control when voltage may drop significantly. The EBCM also monitors for high voltage conditions which could damage the EBCM.

1. The ignition switch is ON.
2. The DTC can be set after system initialization.

1. The EBCM operating voltage falls below 9.4 volts out of ABS/TCS control, or 8.8 volts during ABS/TCS control.
2. The EBCM operating voltage rises above 17.4 volts.
3. The low voltage or the high voltage is detected for more than 500 milliseconds with the vehicle speed above 6 km/h (3.6 mph).

If equipped, the following actions occur

1. A malfunction DTC is stored.
2. The ABS and the Traction Control indicators are turned on.
3. The ABS/TCS is disabled.
4. The Brake warning indicator turns on.

1. The condition for the DTC is no longer present and the DTC is cleared with a scan tool.
2. The electronic brake control module (EBCM) automatically clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles.

1. It is very important that a thorough inspection of the wiring and connectors be performed. Failure to carefully and fully inspect wiring and connectors may result in misdiagnosis, causing part replacement with reappearance of the malfunction.
2. Thoroughly inspect any circuitry that may be causing the complaint for the following conditions: Backed out terminals Improper mating Broken locks Improperly formed or damaged terminals Poor terminal-to-wiring connections Physical damage to the wiring harness
3. The following conditions may cause an intermittent malfunction: A poor connection Rubbed-through wire insulation A broken wire inside the insulation
4. If an intermittent malfunction exists, refer to «Testing for Intermittent Conditions and Poor Connections»(/buick/rendezvous/i-2001-2007/remont/body-electrical/#wiring-systems-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor) in Wiring Systems for further diagnosis.

The number(s) below refer to the step number(s) on the diagnostic table.

1. 2: This step checks if the voltage is above the maximum of the range.
2. 4: Step 4 checks if the voltage is below the minimum of the range.
3. 6: This step checks for the integrity of the ground circuit.

DTC C0896

Symptoms - Antilock Brake System

Visual/Physical Inspection

1. Inspect for aftermarket devices which could affect the operation of the antilock brake system. Refer to «Checking Aftermarket Accessories»(/buick/rendezvous/i-2001-2007/remont/body-electrical/#wiring-systems-diagnostic-information-and-procedures__checking-aftermarket-accessories) in Wiring Systems.
2. Inspect the easily accessible or visible system components for obvious damage or conditions which could cause the symptom.
3. Inspect the master cylinder reservoir for the proper fluid level.

Intermittent

Faulty electrical connections or wiring may be the cause of intermittent conditions. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

Symptom List

Refer to a symptom diagnostic procedure from the following list in order to diagnose the symptom

1. «ABS Indicator Always On»(/buick/rendezvous/i-2001-2007/remont/anti-locktraction-control/#antilock-brake-system-and-traction-control-system)
2. «ABS Indicator Inoperative»(/buick/rendezvous/i-2001-2007/remont/anti-locktraction-control/#antilock-brake-system-and-traction-control-system)
3. «Low Traction Indicator Always On»(/buick/rendezvous/i-2001-2007/remont/anti-locktraction-control/#antilock-brake-system-and-traction-control-system)
4. «Low Traction Indicator Inoperative»(/buick/rendezvous/i-2001-2007/remont/anti-locktraction-control/#antilock-brake-system-and-traction-control-system)
5. «Traction Off Indicator Always On»(/buick/rendezvous/i-2001-2007/remont/anti-locktraction-control/#antilock-brake-system-and-traction-control-system)
6. «Traction Off Indicator Inoperative»(/buick/rendezvous/i-2001-2007/remont/anti-locktraction-control/#antilock-brake-system-and-traction-control-system)

The Instrument Panel Cluster (IPC) turns the ABS Indicator on during the IPC bulb check for approximately 3 seconds when the ignition switch is turned to the ON position. If the EBCM sets a Diagnostic Trouble Code (DTC) the EBCM sends a class 2 message to the IPC to command the ABS Indicator on.

1. It is very important that a thorough inspection of the wiring and connectors be performed. Failure to carefully and fully inspect wiring and connectors may result in misdiagnosis, causing part replacement with reappearance of the malfunction.
2. Thoroughly inspect any circuitry that may be causing the complaint for the following conditions: Backed out terminals Improper mating Broken locks Improperly formed or damaged terminals Poor terminal-to-wiring connections Physical damage to the wiring harness
3. The following conditions may cause an intermittent malfunction: A poor connection Rubbed-through wire insulation A broken wire inside the insulation
4. If an intermittent malfunction exists refer to «Inducing Intermittent Fault Conditions»(/buick/rendezvous/i-2001-2007/remont/body-electrical/#wiring-systems-diagnostic-information-and-procedures__inducing-intermittent-fault-conditions) in Wiring Systems.

The number(s) below refer to the step number(s) on the diagnostic table.

1. 2: Checks if the scan tool can turn on and off all the indicator lamps in the instrument cluster.

1. 4: Checks if the circuits going to the instrument cluster or the cluster is at fault.

ABS Indicator Always On

The Instrument Panel Cluster (IPC) turns the ABS Indicator on during the IPC bulb check for approximately 3 seconds when the ignition switch is turned to the ON position. If the EBCM sets a Diagnostic Trouble Code (DTC) the EBCM sends a class 2 message to the IPC to command the ABS Indicator on.

1. It is very important that a thorough inspection of the wiring and connectors be performed. Failure to carefully and fully inspect wiring and connectors may result in misdiagnosis, causing part replacement with reappearance of the malfunction.
2. Thoroughly inspect any circuitry that may be causing the complaint for the following conditions: Backed out terminals Improper mating Broken locks Improperly formed or damaged terminals Poor terminal-to-wiring connections Physical damage to the wiring harness
3. The following conditions may cause an intermittent malfunction: A poor connection Rubbed-through wire insulation A broken wire inside the insulation
4. If an intermittent malfunction exists refer to «Inducing Intermittent Fault Conditions»(/buick/rendezvous/i-2001-2007/remont/body-electrical/#wiring-systems-diagnostic-information-and-procedures__inducing-intermittent-fault-conditions) in Wiring Systems.

The number(s) below refer to the step number(s) on the diagnostic table.

1. 2: Checks if the scan tool can turn on and off all the indicator lamps in the instrument cluster.

1. 4: Checks if the circuits going to the instrument Cluster or the cluster is at fault.

ABS Indicator Inoperative

The Instrument Panel Cluster (IPC) turns the LOW TRAC Indicator on during the IPC bulb check for approximately 3 seconds when the ignition switch is turned to the ON position. If the EBCM sets a Diagnostic Trouble Code (DTC) the EBCM sends the IPC the command to turn the LOW TRAC Indicator on.

1. It is very important that a thorough inspection of the wiring and connectors be performed. Failure to carefully and fully inspect wiring and connectors may result in misdiagnosis, causing part replacement with reappearance of the malfunction.
2. Thoroughly inspect any circuitry that may be causing the complaint for the following conditions: Backed out terminals Improper mating Broken locks Improperly formed or damaged terminals Poor terminal-to-wiring connections Physical damage to the wiring harness
3. The following conditions may cause an intermittent malfunction: A poor connection Rubbed-through wire insulation A broken wire inside the insulation
4. If an intermittent malfunction exists refer to «Inducing Intermittent Fault Conditions»(/buick/rendezvous/i-2001-2007/remont/body-electrical/#wiring-systems-diagnostic-information-and-procedures__inducing-intermittent-fault-conditions) in Electrical Diagnosis for further diagnosis.

The number(s) below refer to the step number(s) on the diagnostic table.

1. 2: Checks if the scan tool can turn on and off all the indicator lamps in the instrument cluster.

1. 4: Checks if the circuits going to the instrument cluster or the cluster is at fault.

Low Traction Indicator Always On

The Instrument Panel Cluster (IPC) turns the LOW TRAC Indicator on during the IPC bulb check for approximately 3 seconds when the ignition switch is turned to the ON position. If the EBCM sets a Diagnostic Trouble Code (DTC) the EBCM sends the IPC the command to turn the LOW TRAC Indicator on.

1. It is very important that a thorough inspection of the wiring and connectors be performed. Failure to carefully and fully inspect wiring and connectors may result in misdiagnosis, causing part replacement with reappearance of the malfunction.
2. Thoroughly inspect any circuitry that may be causing the complaint for the following conditions: Backed out terminals Improper mating Broken locks Improperly formed or damaged terminals Poor terminal-to-wiring connections Physical damage to the wiring harness
3. The following conditions may cause an intermittent malfunction: A poor connection Rubbed-through wire insulation A broken wire inside the insulation
4. If an intermittent malfunction exists refer to «Inducing Intermittent Fault Conditions»(/buick/rendezvous/i-2001-2007/remont/body-electrical/#wiring-systems-diagnostic-information-and-procedures__inducing-intermittent-fault-conditions) in Wiring System for further diagnosis.

The number(s) below refer to the step number(s) on the diagnostic table.

1. 2: Checks if the scan tool can turn on and off all the indicator lamps in the instrument cluster.

1. 4: Checks if the circuits going to the instrument Cluster or the cluster is at fault.

Low Traction Indicator Inoperative

The TRAC OFF indicator is controlled by the instrument cluster via class 2 serial data messages from the EBCM. When the body control module (BCM) sees the traction control switch input grounded through the momentary traction control switch, it sends a class 2 message to the EBCM that tells the EBCM that the traction control switch has been pressed. The EBCM then disables traction control and sends a message to the instrument cluster to turn the TRAC OFF indicator ON. Each time the ignition is cycled from OFF to ON, the traction control system is enabled.

The following conditions will cause the TRAC OFF indicator to illuminate

1. The EBCM has disabled the TCS due to a DTC.
2. The driver manually disabling the TCS via the traction control switch.
3. The instrument cluster bulb check. When the ignition switch is turned to ON, the TRAC OFF indicator will turn on for approximately 3 seconds and then turn OFF.

1. It is very important that a thorough inspection of the wiring and connectors be performed. Failure to carefully and fully inspect wiring and connectors may result in misdiagnosis, causing part replacement with reappearance of the malfunction.
2. Thoroughly inspect any circuitry that may be causing the complaint for the following conditions: Backed out terminals Improper mating Broken locks Improperly formed or damaged terminals Poor terminal-to-wiring connections Physical damage to the wiring harness
3. The following conditions may cause an intermittent malfunction: A poor connection Rubbed-through wire insulation A broken wire inside the insulation
4. If an intermittent malfunction exists refer to «Inducing Intermittent Fault Conditions»(/buick/rendezvous/i-2001-2007/remont/body-electrical/#wiring-systems-diagnostic-information-and-procedures__inducing-intermittent-fault-conditions) in Wiring Systems for further diagnosis.

Traction Off Indicator Always On

The TRAC OFF indicator is controlled by the instrument cluster via class 2 serial data messages from the EBCM. When the body control module (BCM) sees the traction control switch input grounded through the momentary traction control switch, it sends a class 2 message to the EBCM that tells the EBCM that the traction control switch has been pressed. The EBCM then disables traction control and sends a message to the instrument cluster to turn the TRAC OFF indicator ON. Each time the ignition is cycled from OFF to ON, the traction control system is enabled.

The following conditions will cause the TRAC OFF indicator to illuminate

1. The EBCM has disabled the TCS due to a DTC.
2. The driver manually disabling the TCS via the traction control switch.
3. The instrument cluster bulb check. When the ignition switch is turned to ON, the TRAC OFF indicator will turn on for approximately 3 seconds and then turn OFF.

1. It is very important that a thorough inspection of the wiring and connectors be performed. Failure to carefully and fully inspect wiring and connectors may result in misdiagnosis, causing part replacement with reappearance of the malfunction.
2. Thoroughly inspect any circuitry that may be causing the complaint for the following conditions: Backed out terminals Improper mating Broken locks Improperly formed or damaged terminals Poor terminal-to-wiring connections Physical damage to the wiring harness
3. The following conditions may cause an intermittent malfunction: A poor connection Rubbed-through wire insulation A broken wire inside the insulation
4. If an intermittent malfunction exists refer «Inducing Intermittent Fault Conditions»(/buick/rendezvous/i-2001-2007/remont/body-electrical/#wiring-systems-diagnostic-information-and-procedures__inducing-intermittent-fault-conditions) in Wiring System for further diagnosis.

Traction Off Indicator Inoperative

ABS Automated Bleed Procedure

Note. Refer to Brake Fluid Effects on Paint and Electrical Components Notice in Cautions and Notices.

The following automated ABS bleed procedure is required when one of the following occur

1. Manual bleeding at the wheel cylinders does not achieve the desired pedal height or feel.
2. Brake Pressure Modulator Valve replacement (BPMV).
3. Extreme loss of brake fluid has occurred.
4. Air ingestion is suspected.

If none of the above conditions apply use standard bleed procedures. Refer to Hydraulic Brake System Bleeding (Manual) or Hydraulic Brake System Bleeding (Pressure) in Hydraulic Brakes.

The auto bleed procedure is used on BOSH 5.3 equipped vehicles. This procedure uses a scan tool to cycle the system solenoid valves and run the pump in order to purge the air from the secondary circuits. These secondary circuits are normally closed off, and are only opened during system initialization at vehicle start up and during ABS operation. The automated bleed procedure opens these secondary circuits and allows any air trapped inside the BPMV to flow out toward the wheel cylinders or calipers where it can be purged out of the system.

Automated Bleed Procedure

Preliminary Inspection

1. Inspect the battery for full charge, repair the battery and charging system as necessary. Refer to «Diagnostic System Check - Engine Electrical»(/buick/rendezvous/i-2001-2007/remont/charging-system/#battery-charging-system-and-starting-system) in Engine Electrical.
2. Connect a scan tool to the Data Link Connector (DLC) and select current and history DTCs. Repair any DTCs prior to performing the ABS bleed procedure.
3. Inspect for visual damage and leaks and repair as needed.

Preliminary Setup

1. Raise and vehicle on a suitable support. Refer to «Lifting and Jacking the Vehicle»(/buick/rendezvous/i-2001-2007/remont/hoistjack/#general-information__lifting-and-jacking-the-vehicle) in General Information.
2. Turn the ignition switch to OFF position.
3. Remove all four tires, if necessary refer to «Tire and Wheel Removal and Installation»(/buick/rendezvous/i-2001-2007/remont/wheel-tire-system/#tires-and-wheels) in Tire and Wheel removal and tire installation.
4. Connect the pressure bleeding tool according to the manufacturer's instructions.
5. Turn the ignition switch to RUN position, engine off.
6. Connect a scan tool and establish communications with the ABS system.
7. Pressurize the bleeding tool to 206 to 241 kPa (30 to 35 psi).

Performing the Automated Bleed Procedure

1. With the pressure bleeding tool at 206 to 241 kPa (30 to 35 psi), and all bleeder screws in closed position, select Automated Bleed Procedure on the scan tool and follow the instructions.
2. The first part of the automated bleed procedure will cycle the pump and front release valves for one minute. After the cycling has stopped the scan tool will enter a "cool down" mode and display a 3 minute timer. The auto bleed will not continue until this timer expired, and cannot be overridden.
3. During the next step, the scan tool will request the technician to open one of the bleeder screws. The scan tool will then cycle the respective release valve and pump motor for 1 minute.
4. The scan tool will repeat step 3 for the remaining bleeder screws.
5. With the bleeder tool still attached to the vehicle and maintaining 241 kPa (35 psi), the scan tool will instruct the technician to independently open each bleeder screw for approximately 20 seconds. This should allow any remaining air to be purged from the brake lines.
6. When the automated bleed procedure is completed the scan tool will display the appropriate message.
7. Install all four tires, if necessary refer to «Tire and Wheel Removal and Installation»(/buick/rendezvous/i-2001-2007/remont/wheel-tire-system/#tires-and-wheels) in Tires and Wheels.
8. Remove pressure from the pressure bleeding tool and then disconnect the tool from the vehicle.
9. Depress the brake pedal to gage pedal height and feel. Repeat steps 1 through 8 until the pedal is acceptable.
10. Remove the scan tool from the DLC connector.
11. Install.
12. Lower the vehicle.
13. Inspect the brake fluid level in master cylinder.
14. Road test the vehicle while making sure the brake pedal remains high and firm.

If vehicle is equipped with TCS the scan tool will cycle both the ABS and TCS solenoids valves. This bleed procedure is the same as above.

Electronic Brake Control Module Replacement

Note. Refer to Brake Fluid Effects on Paint and Electrical Components Notice in Cautions and Notices.

Note. Always connect or disconnect the wiring harness connector from the EBCM/EBTCM with the ignition switch in the OFF position. Failure to observe this precaution could result in damage to the EBCM/EBTCM.

Removal Procedure

1. Turn the ignition switch to the OFF position.
2. Remove the air cleaner housing from the engine compartment. Refer to «Air Cleaner Assembly Replacement»(/buick/rendezvous/i-2001-2007/remont/testing-diagnostics/#engine-controls-34l-introduction-service-replacement) in Engine Controls.
3. Disconnect the EBCM harness connector.
4. Brush off any dirt/debris that has accumulated on the assembly.
5. Disconnect the pump motor connector (3) at the bottom of the EBCM.
6. Remove the six EBCM to BPMV screws (2).
7. Separate the EBCM from the BPMV by gently pulling apart until separated (1).

Installation Procedure

1. Clean the BPMV surface with alcohol using a clean rag.
2. Install the EBCM (1) to the BPMV.
3. Install the 6 screws that attaches the EBCM to BPMV. Tighten: Tighten the top 4 mounting screws to 5 N.m (44 lb in). Tighten screws in an X pattern. Tighten the bottom 2 mounting screws to 5 N.m (44 lb in). Connect the pump motor connector to the bottom of the EBCM.
4. Connect the EBCM harness connector and depress the locking tab (1) to secure.
5. Install the air cleaner housing. Refer to «Air Cleaner Assembly Replacement»(/buick/rendezvous/i-2001-2007/remont/testing-diagnostics/#engine-controls-34l-introduction-service-replacement) in Engine Controls.
6. Turn the ignition switch to the RUN position, do not start engine.
7. Perform the «Diagnostic System Check - ABS»(/buick/rendezvous/i-2001-2007/remont/anti-locktraction-control/#antilock-brake-system-and-traction-control-system) .

Brake Pressure Modulator Valve (BPMV) Replacement

Note. Refer to Brake Fluid Effects on Paint and Electrical Components Notice in Cautions and Notices.

1. Turn the ignition switch to the OFF position.
2. Remove the attaching bolts for the cruise control module, if equipped.
3. Swing the cruise control module off to the side, if equipped.
4. Remove the air cleaner housing from the engine compartment. Refer to «Air Cleaner Assembly Replacement»(/buick/rendezvous/i-2001-2007/remont/testing-diagnostics/#engine-controls-34l-introduction-service-replacement) in Engine Controls.
5. Disconnect the electronic brake control module (EBCM) harness connector (1).
6. Disconnect the EBCM to brake pressure modulator valve (BPMV) connector.
7. Disconnect the 4 wheel brake pipes from the BPMV.
8. Swing the 4 wheel brake pipes out of the way only after covering the open pipes to avoid dripping or being contaminated.
9. Disconnect the master cylinder brake pipes from the BPMV.
10. Loosen the brake pipes but do not remove the brake pipes from the master cylinder.
11. Swing the 2 master cylinder brake pipes out of the way only after covering the open pipes to avoid dripping or being contaminated.
12. Remove the 2 lower BPMV mounting bracket nuts (2) from the inner wheel housing mount surface of the strut tower.
13. Loosen the top BPMV mounting nut.
14. Remove the BPMV mounting bracket and the EBCM assembly from the vehicle by sliding up and toward the engine to separate from the wheelhouse slot.
15. Remove the 2 bolts (1) that connect the BPMV to the mounting bracket (2).
16. Remove the EBCM if replacing the BPMV only. Refer to «Electronic Brake Control Module Replacement»(/buick/rendezvous/i-2001-2007/remont/anti-locktraction-control/#antilock-brake-system-and-traction-control-system__electronic-brake-control-module-replacement) .

1. Install EBCM onto the BPMV (1) if replacing the BPMV only. Refer to «Electronic Brake Control Module Replacement»(/buick/rendezvous/i-2001-2007/remont/anti-locktraction-control/#antilock-brake-system-and-traction-control-system__electronic-brake-control-module-replacement) .
2. Install BPMV and EBCM as an assembly to the mounting bracket.
3. Install the 2 bolts (1) that connects the BPMV assembly to the mounting bracket (2). Tighten: Tighten the bolts to 10 N.m (84 lb in).
4. Install the BPMV bracket to the strut tower.
5. Install the 3 nuts (2) that attach the BPMV mounting bracket to the strut tower. Tighten: Tighten the nuts to 10 N.m (89 lb in). Reposition any lines or hoses that were moved out of place.
6. Install the master cylinder brake pipes into the BPMV. Tighten: Tighten the fittings to 24 N.m (18 lb ft).
7. Install the 4 wheel brake pipes on the BPMV. Tighten: Tighten the fittings to 25 N.m (18 lb ft).
8. Connect the EBCM to BPMV connector.
9. Connect the EBCM harness connector.
10. Reinstall the air cleaner housing. Refer to «Air Cleaner Assembly Replacement»(/buick/rendezvous/i-2001-2007/remont/testing-diagnostics/#engine-controls-34l-introduction-service-replacement) in Engine Controls.
11. Reinstall the cruise control module, if equipped.
12. When all procedures have been completed, the automated ABS bleed procedure is required. Refer to «ABS Automated Bleed Procedure»(/buick/rendezvous/i-2001-2007/remont/anti-locktraction-control/#antilock-brake-system-and-traction-control-system__abs-automated-bleed-procedure) .

Scheme 7

1. Raise and support the vehicle on a suitable hoist. Refer to «Lifting and Jacking the Vehicle»(/buick/rendezvous/i-2001-2007/remont/hoistjack/#general-information__lifting-and-jacking-the-vehicle) in General Information.
2. Remove the front tire and wheel assembly. Refer to «Tire and Wheel Removal and Installation»(/buick/rendezvous/i-2001-2007/remont/wheel-tire-system/#tires-and-wheels) in Tires and Wheels.
3. Remove the front wheel speed sensor jumper harness electrical connector (1) from the front wheel speed sensor connector (3).
4. Remove the hub and bearing assembly (2). Refer to «Wheel Bearing/Hub Replacement - Front»(/buick/rendezvous/i-2001-2007/remont/suspension-front/#front-suspension-system) in Front Suspension.

1. Install the hub and bearing assembly (2) to the vehicle. Refer to «Wheel Bearing/Hub Replacement - Front»(/buick/rendezvous/i-2001-2007/remont/suspension-front/#front-suspension-system) in Front Suspension.
2. Install the front wheel speed sensor jumper harness electrical connector (1) to front wheel speed sensor connector (3).
3. Install the wheel and tire assembly. Refer to «Tire and Wheel Removal and Installation»(/buick/rendezvous/i-2001-2007/remont/wheel-tire-system/#tires-and-wheels) in Tires and Wheels.
4. Lower the vehicle.
5. Turn the ignition switch to the RUN position with the engine off.
6. Perform the «Diagnostic System Check - ABS»(/buick/rendezvous/i-2001-2007/remont/anti-locktraction-control/#antilock-brake-system-and-traction-control-system) .

Scheme 8

1. Raise and support the vehicle on a suitable hoist. Refer to «Lifting and Jacking the Vehicle»(/buick/rendezvous/i-2001-2007/remont/hoistjack/#general-information__lifting-and-jacking-the-vehicle) in General Information.
2. Remove the rear tire and wheel assembly. Refer to «Tire and Wheel Removal and Installation»(/buick/rendezvous/i-2001-2007/remont/wheel-tire-system/#tires-and-wheels) in Tires and Wheels.
3. Remove the rear wheel speed sensor electrical connector located next to the rear strut.
4. Remove the hub and bearing assembly (1). Refer to «Wheel Bearing/Hub Replacement - Rear (Front Wheel Drive/Drum)»(/buick/rendezvous/i-2001-2007/remont/suspension-rear/#rear-suspension-system) or «Wheel Bearing/Hub Replacement - Rear (Disc and AWD)»(/buick/rendezvous/i-2001-2007/remont/suspension-rear/#rear-suspension-system) in Rear Suspension.

1. Install the hub and bearing assembly (1) to the vehicle. Refer to «Wheel Bearing/Hub Replacement - Rear (Front Wheel Drive/Drum)»(/buick/rendezvous/i-2001-2007/remont/suspension-rear/#rear-suspension-system) or «Wheel Bearing/Hub Replacement - Rear (Disc and AWD)»(/buick/rendezvous/i-2001-2007/remont/suspension-rear/#rear-suspension-system) in Rear Suspension.
2. Install the rear wheel speed sensor electrical connector.
3. Install the wheel and tire assembly. Refer to «Tire and Wheel Removal and Installation»(/buick/rendezvous/i-2001-2007/remont/wheel-tire-system/#tires-and-wheels) in Tires and Wheels.
4. Lower the vehicle.
5. Turn the ignition switch to the RUN position with the engine off.
6. Perform the «Diagnostic System Check - ABS»(/buick/rendezvous/i-2001-2007/remont/anti-locktraction-control/#antilock-brake-system-and-traction-control-system) .

1. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/buick/rendezvous/i-2001-2007/remont/hoistjack/#general-information__lifting-and-jacking-the-vehicle) in General Information.
2. Remove the tire and wheel. Refer to «Tire and Wheel Removal and Installation»(/buick/rendezvous/i-2001-2007/remont/wheel-tire-system/#tires-and-wheels) in Tires and Wheels.
3. Remove the brake caliper and support the brake caliper. Do NOT disconnect the brake hose. Refer to «Brake Rotor Replacement - Rear»(/buick/rendezvous/i-2001-2007/remont/mechanical-hydraulic/#disc-brake-system__brake-rotor-replacement-rear) in Disc Brakes.
4. Remove the brake caliper bracket. Refer to «Brake Caliper Bracket Replacement - Rear»(/buick/rendezvous/i-2001-2007/remont/mechanical-hydraulic/#disc-brake-system) in Disc Brakes.
5. Remove the brake rotor.
6. Disconnect the wheel speed sensor electrical connector.
7. Disconnect the wheel speed sensor electrical connector from the connector bracket.
8. Disconnect the drive axle from the wheel bearing/hub. Refer to «Wheel Drive Shaft Replacement - Rear»(/buick/rendezvous/i-2001-2007/remont/axle-shafts/#wheel-drive-shafts__wheel-drive-shaft-replacement-rear) in Wheel Drive Shafts.
9. Remove and DISCARD the wheel bearing/hub bolts.
10. Remove the wheel bearing/hub.

1. Install the wheel bearing/hub.
2. Install the NEW wheel bearing/hub bolts. Tighten: Tighten the NEW wheel bearing/hub bolts to 85 N.m (63 lb ft).
3. Connect the drive axle to the wheel bearing/hub. Refer to «Wheel Drive Shaft Replacement - Rear»(/buick/rendezvous/i-2001-2007/remont/axle-shafts/#wheel-drive-shafts__wheel-drive-shaft-replacement-rear) in Wheel Drive Shafts.
4. Install the wheel speed sensor electrical connector to the connector bracket.
5. Connect the wheel speed sensor electrical connector.
6. Install the brake rotor.
7. Install the brake caliper bracket. Refer to «Brake Caliper Bracket Replacement - Rear»(/buick/rendezvous/i-2001-2007/remont/mechanical-hydraulic/#disc-brake-system) in Disc Brakes.
8. Install the brake caliper. Refer to «Brake Rotor Replacement - Rear»(/buick/rendezvous/i-2001-2007/remont/mechanical-hydraulic/#disc-brake-system__brake-rotor-replacement-rear) in Disc Brakes.
9. Install the tire and wheel. Refer to «Tire and Wheel Removal and Installation»(/buick/rendezvous/i-2001-2007/remont/wheel-tire-system/#tires-and-wheels) in Tires and Wheels.
10. Lower the vehicle.

1. Disconnect the front wheel speed sensor jumper harness to ABS harness connector (8).
2. Raise and support the vehicle on a suitable hoist. Refer to «Lifting and Jacking the Vehicle»(/buick/rendezvous/i-2001-2007/remont/hoistjack/#general-information__lifting-and-jacking-the-vehicle) in General Information.
3. Remove the harness (4) from the splash shield retaining clip (5).
4. Remove the harness (4) from the control arm retaining clips (3).
5. Disconnect the front wheel speed jumper harness connector (2) from the front wheel sensor.
6. Remove the front wheel speed sensor jumper harness (1).

1. Connect the front wheel speed sensor jumper harness connector (2) to the wheel speed sensor.
2. Install the harness (4) to control arm retaining clips (3).
3. Install the harness (4) to splash shield retaining clip (5).
4. Lower the vehicle.
5. Connect the front wheel speed sensor jumper harness to ABS harness connector (8).
6. Turn the ignition switch to the RUN position, with the engine off.
7. Perform the diag system check. Refer to «Diagnostic System Check - ABS»(/buick/rendezvous/i-2001-2007/remont/anti-locktraction-control/#antilock-brake-system-and-traction-control-system) .

1. Raise and support the vehicle on a suitable hoist. Refer to «Lifting and Jacking the Vehicle»(/buick/rendezvous/i-2001-2007/remont/hoistjack/#general-information__lifting-and-jacking-the-vehicle) in General Information.
2. Disconnect the rear wheel speed jumper harness connector at the pass thru connector.
3. Remove the rear wheel speed sensor jumper harness (1) from the retaining clips (2).
4. Disconnect the rear wheel speed sensor jumper harness connector (1) from the wheel speed sensor, located next to the rear strut (2).
5. Remove the rear wheel speed sensor jumper harness.

1. Connect the rear wheel speed sensor jumper harness connector (1) to the wheel speed sensor, located next to the rear strut (2).
2. Install the rear wheel speed jumper harness (1) into the retaining clips (2).
3. Connect the rear wheel speed sensor jumper harness connector to the pass thru connector.
4. Lower the vehicle.
5. Turn the ignition switch to the RUN position, with the engine off.
6. Perform the diag system check. Refer to «Diagnostic System Check - ABS»(/buick/rendezvous/i-2001-2007/remont/anti-locktraction-control/#antilock-brake-system-and-traction-control-system) .

1. Remove the instrument panel accessory trim plate. Refer to «Trim Plate Replacement - Instrument Panel (I/P) Accessory (Aztek)»(/buick/rendezvous/i-2001-2007/remont/gauges-instrument-panels/#instrument-panel-system-displays-gauges-and-console) in Instrument Panel, Gages and Console.
2. Remove the bolts/screws from the switch bank to instrument panel.
3. Pull straight out from the instrument panel in order to remove the switch bank from the instrument panel.
4. Disconnect the electrical connectors.

1. Connect the electrical connectors.
2. Push in on the switch bank in order to install the switch bank.
3. Install the bolts/screws to the switch bank to instrument panel. Tighten: Tighten the bolts/screws to 2.5 N.m (22 lb in).
4. Install the instrument panel accessory trim plate. Refer to «Trim Plate Replacement - Instrument Panel (I/P) Accessory (Aztek)»(/buick/rendezvous/i-2001-2007/remont/gauges-instrument-panels/#instrument-panel-system-displays-gauges-and-console) in Instrument Panel, Gages and Console.

Scheme 9

Scheme 10

This vehicle is equipped with the Bosch 5.3 antilock braking system.

The vehicle is equipped with the following braking systems

1. Antilock Brake System (ABS)
2. Dynamic Rear Proportioning (DRP)
3. Traction Control System (TCS) (w/NW9)

The following components are involved in the operation of the above systems

1. Electronic Brake Control Module (EBCM) - The EBCM controls the system functions and detects failures. The EBCM contains the following components: System Relay - The system relay is energized when the ignition is ON and no ABS DTCs are present. It supplies battery positive voltage to the solenoid valves and pump motor. Vent Tube - The vent tube, located in the EBCM connector, is an opening to the internal cavity of the EBCM. It allows ventilation of the EBCM internals.
2. Brake Pressure Modulator Valve (BPMV) - The BPMV contains the hydraulic valves and pump motor that are controlled electrically by the EBCM. The BPMV uses a 4 circuit configuration with a diagonal split. The BPMV directs fluid from the reservoir of the master cylinder to the left front and right rear wheels and fluid from the other reservoir to the right front and left rear wheels. The diagonal circuits are hydraulically isolated so that a leak or malfunction in one circuit will allow continued braking ability on the other. IMPORTANT: There is a rubber isolator located under the BPMV and on the mounting studs. The rubber isolators protect the BPMV and the EBCM from vehicle vibrations. The BPMV contains the following components: Pump Motor Inlet Valves (one per wheel) Outlet Valves (one per wheel) Master Cylinder Isolation Valves (w/NW9) (one per drive wheel) Prime Valves (w/NW9) (one per drive wheel)
3. Wheel Speed Sensors (WSS) - As the wheel spins, the wheel speed sensor produces an AC signal. The EBCM uses this AC signal to calculate wheel speed. The wheel speed sensors are replaceable only as part of the wheel hub and bearing assemblies.
4. Traction Control Switch (w/NW9) - The TCS is manually disabled or enabled using the traction control switch.
5. Stoplamp Switch - The EBCM uses the stoplamp switch as an indication that the brake pedal is applied.

Initialization Sequence

The EBCM performs one initialization test each ignition cycle. The initialization of the EBCM occurs when one set of the following conditions occur

Both of the following conditions occur

1. The EBCM receives that there is a minimum of 500 rpm from the PCM via class 2 serial data message.
2. The stoplamp switch is not applied.

or

Both of the following conditions occur

1. The vehicle speed is greater than 16 km/h (10 mph).
2. The stoplamp switch is applied.

The initialization sequence may also be commanded with a scan tool.

The initialization sequence cycles each solenoid valve and the pump motor (as well as the necessary relays) for approximately 1.5 seconds to check component operation. The EBCM sets a DTC if any error is detected. The initialization sequence may be heard and felt while it is taking place, and is considered part of normal system operation.

The EBCM defines a drive cycle as the completion of the initialization sequence.

When wheel slip is detected during a brake application, the ABS enters antilock mode. During antilock braking, hydraulic pressure in the individual wheel circuits is controlled to prevent any wheel from slipping. A separate hydraulic line and specific solenoid valves are provided for each wheel. The ABS can decrease, hold, or increase hydraulic pressure to each wheel brake. The ABS cannot, however, increase hydraulic pressure above the amount which is transmitted by the master cylinder during braking.

During antilock braking, a series of rapid pulsations is felt in the brake pedal. These pulsations are caused by the rapid changes in position of the individual solenoid valves as the EBCM responds to wheel speed sensor inputs and attempts to prevent wheel slip. These pedal pulsations are present only during antilock braking and stop when normal braking is resumed or when the vehicle comes to a stop. A ticking or popping noise may also be heard as the solenoid valves cycle rapidly. During antilock braking on dry pavement, intermittent chirping noises may be heard as the tires approach slipping. These noises and pedal pulsations are considered normal during antilock operation.

Vehicles equipped with ABS may be stopped by applying normal force to the brake pedal. Brake pedal operation during normal braking is no different than that of previous non-ABS systems. Maintaining a constant force on the brake pedal provides the shortest stopping distance while maintaining vehicle stability.

Pressure Hold

The EBCM closes the inlet valve and keeps the outlet valve closed in order to isolate the system when wheel slip occurs. This holds the pressure steady on the brake so that the hydraulic pressure does not increase or decrease.

Pressure Decrease

The EBCM decreases the pressure to individual wheels during a deceleration when wheel slip occurs. The inlet valve is closed and the outlet valve is opened. The excess fluid is stored in the accumulator until the return pump can return the fluid to the master cylinder.

Pressure Increase

The EBCM increases the pressure to individual wheels during a deceleration in order to reduce the speed of the wheel. The inlet valve is opened and the outlet valve is closed. The increased pressure is delivered from the master cylinder.

Dynamic Rear Proportioning (DRP)

The dynamic rear proportioning (DRP) is a control system that replaces the hydraulic proportioning function of the mechanical proportioning valve in the base brake system. The DRP control system is part of the operation software in the EBCM. The DRP uses active control with existing ABS in order to regulate the vehicle's rear brake pressure.

The red brake warning indicator is illuminated when the dynamic rear proportioning function is disabled.

Traction Control System (TCS) (NW9)

When drive wheel slip is noted while the brake is not applied, the EBCM will enter traction control mode.

First, the EBCM requests the PCM to reduce the amount of torque to the drive wheels via the requested torque signal circuit. The PCM reduces torque to the drive wheels by retarding spark timing and turning off fuel injectors. The PCM reports the amount torque delivered to the drive wheels via the delivered torque signal circuit.

If the engine torque reduction does not eliminate drive wheel slip, the EBCM will actively apply the drive wheel brakes. During traction control braking, hydraulic pressure in each drive wheel circuit is controlled to prevent the drive wheels from slipping. The master cylinder isolation valve closes in order to isolate the master cylinder from the rest of the hydraulic system. The prime valve then opens in order to allow the pump to accumulate brake fluid in order to build hydraulic pressure for braking. The drive wheel inlet and outlet solenoid valves then open and close in order to perform the following functions

1. Pressure hold
2. Pressure increase
3. Pressure decrease

ABS Indicator

The IPC illuminates the ABS indicator when the following occurs

1. The electronic brake control module (EBCM) detects a malfunction with the antilock brake system. The IPC receives a class 2 message from the EBCM requesting illumination.
2. The IPC performs the displays test at the start of each ignition cycle. The indicator illuminates for approximately 3 seconds.

The IPC sends a class 2 message to the radio for audible warning when this indicator is on.

Brake Warning Indicator

The IPC illuminates the brake indicator when the following occurs

1. The body control module (BCM) detects that the park brake is engaged. The IPC receives a class 2 message from the BCM requesting illumination. If the vehicle is shifted out of park with the park brake engaged and a class 2 message is received indicating that the vehicle speed is greater than 3 MPH, the BCM sends a class 2 message to the radio in order to activate the audible warning.
2. The IPC performs the displays test at the start of each ignition cycle. The indicator illuminates for approximately 3 seconds.

Low Brake Fluid Indicator

The IPC illuminates the low brake fluid indicator in the message center when the IPC receives a low signal from the low brake fluid switch. The IPC sends a class 2 message to the radio in order to activate an audible warning.

Service Traction System

The IPC illuminates the Service Traction System indicator in the message center when the electronic brake control module (EBCM) detects a malfunction in the traction control system. The IPC receives a class 2 message from the EBCM requesting illumination.

The IPC sends a class 2 message to the radio in order to activate an audible warning.

Traction Active

The IPC illuminates the Traction Active indicator in the message center when the electronic brake control module (EBCM) detects a traction control event. The IPC receives a class 2 message from the EBCM requesting illumination.

Trac Off

The IPC illuminates the TRAC OFF indicator when

1. The electronic brake control module (EBCM) inhibits the traction control system. The IPC receives a class 2 message from the EBCM requesting illumination.
2. The IPC performs the displays test at the start of each ignition cycle. The indicator illuminates for approximately 3 seconds.

The IPC sends a class 2 message to the radio in order to activate an audible warning.

Special Tools

Special Tools Illustration Tool Number/Description J 39200 Digital Multimeter J 39700 Universal Pinout Box J 39700-530 Cable Adapter Tech 2 Scan Tool

Scheme 11

Scheme 12

See also:
• Scan Tool Does Not Power Up
• Diagnostic Trouble Code (DTC) List
• Diagnostic Trouble Code (DTC) List
• Testing for Intermittent Conditions and Poor Connections
• Body Control System Connector End Views
• Circuit Testing
• Wiring Repairs
• Connector Repairs
• Lifting and Jacking the Vehicle
• Wheel Bearing/Hub Replacement - Front
• Wheel Bearing/Hub Replacement - Rear (Front Wheel Drive/Drum)
• Lighting Systems Connector End Views
• Powertrain Control Module (PCM) Connector End Views
• Diagnostic System Check - Engine Controls
• Diagnostic Trouble Code (DTC) List
• Service Programming System (SPS)
• Powertrain Control Module (PCM) Replacement
• Checking Aftermarket Accessories
• Symptoms - Engine Electrical
• Inducing Intermittent Fault Conditions
• Instrument Panel, Gages, and Console Connector End Views
• Instrument Panel Cluster (IPC) Replacement
• Testing for Short to Ground
• Testing for Continuity
• Brake Fluid Irritant Caution
• Brake Fluid Effects on Paint and Electrical Components Notice
• Hydraulic Brake System Bleeding (Manual)
• Diagnostic System Check - Engine Electrical
• Tire and Wheel Removal and Installation
• Air Cleaner Assembly Replacement
• Fastener Notice
• Brake Rotor Replacement - Rear
• Brake Caliper Bracket Replacement - Rear
• Wheel Drive Shaft Replacement - Rear
• Diagnostic System Check - ABS
• Symptoms - Antilock Brake System
• Diagnostic Trouble Code (DTC) List
• ABS Automated Bleed Procedure
• ABS Connector End Views
• Electronic Brake Control Module Replacement
• Brake Pressure Modulator Valve (BPMV) Replacement