Antilock Brake System, Traction Control System & Stability Control System Cadillac STS I

Fastener Tightening Specifications

Fastener Tightening Specifications

ABS Schematic Icons

ABS Schematic Icons Icon Icon Definition IMPORTANT: Twisted-pair wires provide an effective shield that helps protect sensitive electronic components from electrical interference. If the wires were covered with shielding, install new shielding. In order to prevent electrical interference from degrading the performance of the connected components, you must maintain the proper specification when making any repairs to the twisted-pair wires shown : The wires must be twisted a minimum of 9 turns per 31 cm (12 in) as measured anywhere along the length of the wires. The outside diameter of the twisted wires must not exceed 6.0 mm (0.25 in)

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ABS Connector End Views

Brake Fluid Pressure Sensor Connector End Connector Part Information OEM: 2-967642-1 Service: 3-Way F Amp (BK) Terminal Part Information Terminal: Terminal Seal: Release Tool: Core Crimp: Insulation Crimp: Test Probe: Pin Wire Color Circuit No. Function 1 L-GN/BK 1338 Yaw Rate Sensor Signal (2) 2 PU 5002 Brake Pressure Modulator Valve 3 GY/BK 1337 Yaw Rate Sensor Volt Reference

Electronic Brake Control Module (EBCM) Connector End Connector Part Information OEM: 15412357 Service: 50-Way F Delphi (Unknown Style) (BK) Terminal Part Information Terminal: Terminal Seal: Release Tool: Core Crimp: Insulation Crimp: Test Probe: Pin Wire Color Circuit No. Function A RD/BK 342 Battery Positive Voltage B RD/BK 342 Battery Positive Voltage C BN 2039 Run Ignition 3 Voltage D - - Not Used E BK 1150 Ground F BK 1150 Ground G GY 1787 Variable Effort Steering Actuator High Effort Control H WH 345 Variable Effort Steering Actuator Low Effort Control A1 YE 873 Left Front Wheel Speed Sensor Low Reference A2 L-BU 830 Wheel Speed Sensor Signal Left Front A3 D-GN 872 Wheel Speed Sensor Signal Right Front A4 TN 833 Wheel Speed Sensor Low Reference Right Front A5 TN 884 Wheel Speed Sensor Signal Left Rear A6 OG 885 Wheel Speed Sensor Low Reference Left Rear A7 BN 882 Wheel Speed Sensor Signal Right Rear A8 WH 883 Wheel Speed Sensor Low Reference Right Rear A9-A10 - - Not Used A11 YE 5727 High Speed GMLAN Serial Data Wake Up B1 PU/WH 1699 Combined Vehicle Inertial Sensor Lat/Long Rate Signal B2-B8 - - Not Used B9 TN 2501 High Speed GMLAN Serial Data (-) (1) B10 TN 2501 High Speed GMLAN Serial Data (-) (1) B11 TN/BK 2500 High Speed GMLAN Serial Data (+) (1) B12 TN/BK 2500 High Speed GMLAN Serial Data (+) (1) B13 L-GN/BK 1338 Yaw Rate Sensor Signal (2) B14 GY/BK 1337 Yaw Rate Sensor Volt Reference C1-C5 - - Not Used C6 L-BU 1764 Steering Wheel Position Signal B C7 L-GN 1763 Steering Wheel Position Signal A C8 D-BU 716 Yaw Rate Sensor Signal (1) C9 L-BU 715 Lateral Accelerometer Signal C10 PU 5002 Brake Pressure Modulator Valve

Steering Angle Sensor Connector End Connector Part Information 12064978 6-Way F Micro-Pack 100 Series (GY) Pin Wire Color Circuit No. Function 1 GY/BK 1337 5-Volt reference 2 L-GN/BK 1338 Low Reference 3-4 - - Not Used 5 L-GN 1763 Steering Wheel Position Signal A 6 L-BU 1764 Steering Wheel Position Signal B

Traction Control Switch Connector End Connector Part Information OEM: 12059800 Service: 15306169 5-Way F Metri-Pack 150 Series (BK) Terminal Part Information Terminal: Terminal Seal: Release Tool: Core Crimp: Insulation Crimp: Test Probe: Pin Wire Color Circuit No. Function A-B - - Not Used C BN/WH 1571 Traction Control Switch Signal (2) D BK/WH 451 Ground E YE 1491 Backlight Lamp Control

Wheel Speed Sensor (WSS) - LF Connector End Connector Part Information OEM: 12052644 Service: NS 2-Way F Metri-Pack 150 Series Sealed (GY) Terminal Part Information Terminal: Terminal Seal: Release Tool: Core Crimp: Insulation Crimp: Test Probe: Pin Wire Color Circuit No. Function A YE 873 Left Front Wheel Speed Sensor Low Reference B L-BU 830 Wheel Speed Sensor Signal Left Front

Wheel Speed Sensor (WSS) - LR Connector End Connector Part Information OEM: 12052644 Service: NS 2-Way F Metri-Pack 150 Series Sealed (GY) Terminal Part Information Terminal: Terminal Seal: Release Tool: Core Crimp: Insulation Crimp: Test Probe: Pin Wire Color Circuit No. Function A TN 884 Wheel Speed Sensor Signal Left Rear B OG 885 Wheel Speed Sensor Low Reference Left Rear

Wheel Speed Sensor (WSS) - RF Connector End Connector Part Information OEM: 12052644 Service: NS 2-Way F Metri-Pack 150 Series Sealed (GY) Terminal Part Information Terminal: Terminal Seal: Release Tool: Core Crimp: Insulation Crimp: Test Probe: Pin Wire Color Circuit No. Function A D-GN 872 Wheel Speed Sensor Signal Right Front B TN 833 Wheel Speed Sensor Low Reference Right Front

Wheel Speed Sensor (WSS) - RR Connector End Connector Part Information OEM: 12052644 Service: NS 2-Way F Metri-Pack 150 Series Sealed (GY) Terminal Part Information Terminal: Terminal Seal: Release Tool: Core Crimp: Insulation Crimp: Test Probe: Pin Wire Color Circuit No. Function A BN 882 Wheel Speed Sensor Signal Right Rear B WH 883 Wheel Speed Sensor Low Reference Right Rear

Yaw Rate and Lateral Acceleration Sensor Connector End Connector Part Information OEM: 15326822 Service: 15326822 5-Way F GT 150 Series Sealed 4.0 (BK) Terminal Part Information Terminal: Terminal Seal: Release Tool: Core Crimp: Insulation Crimp: Test Probe: Pin Wire Color Circuit No. Function A PU/WH 1699 Combined Vehicle Inertial Sensor Lat/Long Rate Signal B GY/BK 1337 Yaw Rate Sensor Volt Reference C D-BU 716 Yaw Rate Sensor Signal (1) D L-GN/BK 1338 Yaw Rate Sensor Signal (2) E L-BU 715 Lateral Accelerometer Signal

Diagnostic Starting Point - Antilock Brake System

Begin the system diagnosis with Diagnostic System Check - Vehicle in Vehicle DTC Information. 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.

Scan Tool Output Controls

Electronic Brake Control Module (EBCM) Output Controls

Scan Tool Data List

Dash Integration Module (DIM) Data List

Electronic Brake Control Module (EBCM) Data List

Instrument Panel Cluster (IPC) Data List

Engine Control Module (ECM) Data List

Rear Integration Module (RIM) Data List

Diagnostic Test Drive

When servicing vehicles with the vehicle stability enhancement system (VSES), 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, or VSES concerns.

The following is a suggested VSES diagnostic test drive.

1. Read the Diagnostic Aids and the Conditions for Setting the DTC.
2. Turn OFF the ignition.
3. Reconnect any previously disconnected components.
4. Start the engine.
5. Install a scan tool.
6. With the scan tool, observe the VSES Is Centered parameter in the VSES data list. The scan tool will indicate Yes with the steering wheel centered. Drive the vehicle in a straight line for 45 seconds at 24 km/h (15 mph) while monitoring the scan tool.
7. Remove the scan tool.
8. Drive the vehicle under the following conditions for at least 10 minutes. Highway driving Rough roads Perform turning maneuvers (curved freeway entrance ramp, parking lot maneuvers) and high steering angles and yaw rates at low speeds. Verify the customers concern and duplicate driving conditions
9. With the engine still running, use the scan tool in order to check for DTCs. If any DTCs are set, refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/cadillac/sts/i-2004-2007/remont/oem-general-information/#vehicle-dtc-information__diagnostic-trouble-code-dtc-list) in Vehicle DTC Information.

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.

Circuit Description

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.

DTC Descriptors

This diagnostic procedure supports the following DTCs

1. DTC C0035 LF Wheel Speed Sensor Circuit
2. DTC C0040 RF Wheel Speed Sensor Circuit
3. DTC C0045 LR Wheel Speed Sensor Circuit
4. DTC C0050 RR Wheel Speed Sensor Circuit

This vehicle has DTCs which include DTC Symptoms. For more information on DTC Symptoms, refer to DTC Symptom Description in Vehicle DTC Information.

DTC C0035-C0051

Conditions for Running the DTC

C0035 - C0050 00 and 0F

1. The ignition is ON.
2. The ignition voltage is greater than 8-volts.

C0035 - C0050 18

1. The ignition is ON.
2. The ignition voltage is greater than 8-volts.
3. The brake pedal is not pressed.
4. The ABS is not active.

C0035 - C0050 00

One of the following conditions exists for 0.02 seconds

1. A short to voltage - the wheel speed sensor signal circuit and wheel speed sensor return circuit voltages are both greater than 4.25 volts.
2. A short to ground - the wheel speed sensor signal circuit and wheel speed sensor return circuit voltages are both less than 0.75 volts.
3. An open - the wheel speed sensor signal circuit voltage is greater than 4.25 volts and wheel speed sensor return circuit voltage is less than 0.75 volts.

C0035 - C0050 0F

The EBCM detects a rapid variation in the wheel speed. The wheel speed changes by 20 km/h (12 mph) or more in 0.01 second. The change must occur 3 times with no more than 0.2 seconds between occurrences.

C0035 - C0050 18

All of the following conditions exists for .2 seconds

1. The suspect wheel speed equals zero.
2. The other wheel speeds are greater than 8 km/h (5 mph).
3. The other wheel speeds are within 11 km/h (7 mph) of each other.

Action Taken When the DTC Sets

If equipped, the following actions occur

1. The EBCM disables the ABS/EDC/TCS/TPM/VSES for the duration of the ignition cycle.
2. The ACC braking function is disabled.
3. The DRP does not function optimally.
4. The ABS indicator turns ON.
5. The Traction Control indicator turns ON.
6. The DIC displays the Service Stability System message.

Conditions for Clearing the DTC

1. The condition for the DTC is no longer present and the DTC is cleared with a scan tool.
2. The 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 (9.9 ml) 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.

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 to close to high energy ignition system components, such as spark plug wires.

Under the following conditions, DTCs are set

1. The 2 suspect wheel speeds equal zero for 60 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.

Test Description

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

1. 3: Measure the resistance of the wheel speed sensor in order to determine if the sensor has a valid resistance value.
2. 4: Ensures that the wheel speed sensor is generating a valid A/C voltage output.

DTC C0035-C0051

The electronic brake control module (EBCM) supplies ground to activate the ABS pump motor. An internal system relay in the EBCM supplies battery positive voltage to the pump motor when the ignition is turned ON. The EBCM monitors pump motor feedback voltage after activation to detect a stalled or binding pump motor.

This diagnostic procedure supports the following DTC

DTC C0110 Pump Motor Circuit

This vehicle has DTCs which include DTC Symptoms. For more information on DTC Symptoms, refer to DTC Symptom Description in Vehicle DTC Information.

DTC C0110

C0110 04

1. System and ignition voltage is between 10.5 and 17 volts.
2. The system enable relay is ON.
3. The pump motor has been commanded OFF for 2.5 seconds.

C0110 07

1. System and ignition voltage is between 10.5 and 17 volts.
2. The system enable relay is ON.

C0110 61

1. DTC C0110 04 or 07 are not set.
2. The system enable relay is ON.
3. The pump motor has been commanded ON for .3 seconds.

C0110 04

The EBCM detects an open in the pump motor circuit when the voltage across the pump motor is between 10 and 90 percent of ignition voltage.

C0110 07

This code sets for a open in the pump motor driver circuit when the pump is commanded on and the following conditions exist.

1. The voltage across the pump is less than 8 volts.
2. The voltage at the high side of the motor is greater than 9.25 volts.
3. The EBCM detects a open in the low side pump motor driver circuit.

C00110 61

The pump motor continues to rotate briefly after activation creating a feedback voltage. The EBCM sets the code if the measured feedback voltage indicates a binding or stalled pump motor.

If equipped, the following actions occur

1. The EBCM disables the ABS/TCS/VSES for the duration of the ignition cycle.
2. ACC Braking Function is Disabled.
3. DRP is degraded.
4. The ABS indicator turns ON.
5. The Traction Control indicator turns ON.
6. The DIC displays the Service Stability System message.

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.

Diagnostic Aids

The pump motor is integral to the BPMV. The pump motor is not serviceable.

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

1. 5: Tests the ability of the EBCM to control the pump motor. If the test lamp illuminates, the pump motor circuit within the EBCM is good.

DTC C0110

The electronic brake control module (EBCM) uses the input from the brake fluid pressure sensor to enhance Antilock Brake System (ABS) braking and vehicle stability if equipped.

DTC Descriptor

This diagnostic procedure supports the following DTC

DTC C0136 Base Brake System Pressure Circuit

This vehicle has DTCs which include DTC Symptoms. For more information on DTC Symptoms, refer to DTC Symptom Description in Vehicle DTC Information.

DTC C0136

The ignition is ON for 1 second.

C0136 00

One of the following conditions exists for 0.1 seconds.

1. The brake fluid pressure sensor signal is greater than 4.9 volts.
2. The brake fluid pressure sensor signal is less than 0.15 volts.

C0136 08

The EBCM performs a diagnostic test on the base brake system pressure circuit and sensor when the ignition is turned ON. If the diagnostic determines a faulty sensor or wiring, the DTC will set.

If equipped, the fallowing actions will occur.

1. The EBCM disables the Vehicle Stability Enhancement System (VSES) for the duration of the ignition cycle.
2. Traction Control System (TCS) is degraded.
3. Adaptive cruise control (ACC) braking function is disabled.
4. The Traction Control and Active Handling indicator turns ON.
5. The driver information center (DIC) displays the Service Active Handling message.

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

If equipped, the brake pressure sensor 5-volt reference circuit and low reference circuit is shared with other components in the vehicle stability system. DTCs can set for other components that share circuits with the brake pressure sensor.

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

1. 2: This step tests for the proper voltage output on the 5-volt reference circuit and the proper operation of the signal circuit.
2. 3: This step tests for possible low 5-volt reference output or a problem with the signal circuit.
3. 4: This step tests for a short to voltage on the 5-volt reference circuit. If a short to voltage exists, other DTC's may be set for the vehicle stability system if equipped.
4. 8: This step tests for a problem with the low reference circuit. If a short to voltage exists, other DTC's may be set for the vehicle stability system if equipped.

DTC C0136

The electronic brake control module (EBCM) uses the input from the brake fluid pressure sensor for more accurate braking control during vehicle stability enhancement system (VSES).

This diagnostic procedure supports the following DTC

DTC C0137 Base Brake System Pressure Circuit Range

This vehicle has DTCs which include DTC Symptoms. For more information on DTC Symptoms, refer to DTC Symptom Description in Vehicle DTC Information.

DTC C0137

1. The ignition is ON.
2. Ignition voltage is greater than 8 volts.

Conditions for Setting the DTC

The brake fluid pressure is less than 345 kPa (50 psi) for 3 deceleration cycles.

1. The EBCM disables the VSES and traction control for the duration of the ignition cycle.
2. The Traction Control indicator turns ON.
3. The driver information center (DIC) displays the Service Vehicle Stability message.
4. The Antilock Brake System (ABS) remains functional.

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

1. Find out from the driver under what conditions the DTC was set, when the DIC displayed the Service Active Handling message. This information will help to duplicate the failure.
2. The Snapshot function on the scan tool can help find an intermittent DTC.
3. A deceleration cycle consists of the following sequence: The vehicle speed is greater than 24 km/h (15 mph). The vehicle decelerates more than 8 km/h/second (5 mph/second) for 2 seconds. The vehicle speed decelerates to less than 16 km/h (10 mph).

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

1. 2: Tests for the proper voltage output on the 5-volt reference circuit and the proper operation of the signal circuit.
2. 3: Tests for possible low 5-volt reference output or a problem with the signal circuit.
3. 4: Tests for a short to voltage on the 5-volt reference circuit. If a short to voltage exists, other DTC's may be set for the vehicle stability system if equipped.
4. 8: Tests for a problem with the low reference circuit. If a short to voltage exists, other DTCs may be set for the vehicle stability system if equipped.

DTC C0137

The brake pedal position (BPP) sensor is an input to the instrument panel module (IPM). The IPM then sends a serial data message to the electronic brake control module (EBCM) and other electronic control modules. The BPP sensor is a potentiometer type sensor with a 5-volt reference circuit and a low reference circuit. The IPM supplies the 5-volt reference to the BPP.

This diagnostic procedure supports the following DTC

DTC C0161 ABS/TCS Brake Switch Circuit

This vehicle has DTCs which include DTC Symptoms. For more information on DTC Symptoms, refer to DTC Symptom Description in Vehicle DTC Information.

DTC C0161

C0161 11

1. The ignition is ON.
2. The vehicle speed is greater than 16 km/h (10 mph).
3. The ignition voltage is greater than 8 volts.

C0161 12

1. The ignition is ON.
2. The ignition voltage is greater than 8 volts.

C0161 11

1. The brake pedal is sensed as applied.
2. The vehicle speed is greater than 40 km/h (25 mph).
3. The vehicles acceleration exceeds 8 km/h per second (5 mph per second).

C0161 12

1. The brake pedal is not applied.
2. The master cylinder pressure is greater than 150 psi.
3. The vehicle speed is greater than 24 km/h (14 mph).
4. The vehicles deceleration exceeds 11.5 km/h per second (7 mph per second).

If equipped, the following actions occur

1. The EBCM disables the engine drag control (EDC)/tire pressure monitor (TPM)/vehicle stability enhancement system (VSES) for the duration of the ignition cycle.
2. The traction control system (TCS) is degraded.
3. The traction control and active handling indicator turns ON.
4. The driver information center (DIC) displays the following messages: Service Traction Control System Service Vehicle Stability System
5. The antilock brake system (ABS) remains functional.

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

The DTC C0161.11 can be set if the vehicle has been driven with the brake applied during acceleration.

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

1. 2: This step checks if there is other DTCs that can cause the BPP failure.
2. 4: This step checks to see if the DTC will reset as current.

DTC C0161

The electronic brake control module (EBCM) monitors vehicle speed deceleration, system activation, and brake pedal position sensor active times in order to calculate an estimate of the brake rotor temperatures. If the EBCM calculates that the brake rotor temperatures have exceeded the thermal cutoff point, the EBCM will temporarily suspend the Traction Control System (TCS) function until the brake rotors cool. This feature is used to maintain braking effectiveness if normal base braking is required. An overly heated brake system could result in brake fade.

The EBCM continues calculating the brake rotor temperatures after the ignition is turned OFF. The EBCM remains awake until the EBCM calculates that the brake rotors cooled sufficiently. The cooling period may take up to 30 minutes.

This diagnostic procedure supports the following DTC

DTC C0179 System Thermal High

1. The ignition is ON.
2. Ignition voltage is greater than 8 volts.

This DTC sets when the estimated brake rotor temperature exceeds 375°C (700°F). When the estimated brake rotor temperature exceeds 375°C (700°F) during normal braking or ABS operations, the DTC does not set until the next TCS activation. The EBCM does not disable TCS until the end of the TCS event.

1. The EBCM disables the TCS until the DTC becomes a history DTC.
2. The Antilock Brake System (ABS) remains functional.
3. The Traction Control indicator turns ON.

1. The current DTC becomes history when the estimated brake rotor temperatures of both drive wheels decreases below 275°C (530°F). The following actions also occur: The EBCM enables the TCS. The driver information center (DIC) displays the Traction Ready message.
2. The condition for the DTC is no longer present (the DTC is not current) and you used the scan tool Clear DTC function.
3. The condition for the DTC is no longer present (the DTC is not current) and you used the On-Board Diagnostics Clear DTC function.
4. The EBCM automatically clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles.

DTC C0179 does not indicate a malfunction has occurred. This DTC indicates that the EBCM has reacted to high brake rotor temperatures by temporarily suspending TCS.

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

1. 2: This step tests if driving conditions caused DTC.

DTC C0179

The vehicle stability enhancement system (VSES) is activated by the electronic brake control module (EBCM) calculating the desired yaw rate and comparing it to the actual yaw rate input. The desired yaw rate is calculated from measured steering wheel position, vehicle speed, and lateral acceleration. The difference between the desired yaw rate and actual yaw rate is the yaw rate error, which is a measurement of oversteer or understeer. If the yaw rate error becomes too large, the EBCM will attempt to correct the vehicle's yaw motion by applying differential braking to the left or right front wheel.

The amount of differential braking applied to the left or right front wheel is based on both the yaw rate error and side slip rate error. The side slip rate error is a function of the lateral acceleration minus the product of the yaw rate and vehicle speed. The yaw rate error and side slip rate error are combined to produce the total delta velocity error. When the delta velocity error becomes too large and the VSES system activates, the drivers steering inputs combined with the differential braking will attempt to bring the delta velocity error toward zero.

The VSES activations generally occur during aggressive driving, in the turns or bumpy roads without much use of the accelerator pedal. When braking during VSES activation, the brake pedal will feel different than the ABS pedal pulsation. The brake pedal pulsates at a higher frequency during VSES activation.

This diagnostic procedure supports the following DTC

DTC C0186 Lateral Accelerometer Circuit

This vehicle has DTCs which include DTC Symptoms. For more information on DTC Symptoms, refer to DTC Symptom Description in Vehicle DTC Information.

DTC C0186

C0186 00, 09, and 1A

1. The ignition is ON.
2. The ignition voltage is greater than 8 volts.

C0186 08

1. The ignition is ON.
2. The ignition voltage is greater than 8 volts.
3. The vehicle speed is greater than 0 km/h (0 mph).

C0186 19

1. The ignition is ON.
2. The ignition voltage is greater than 8 volts.
3. The vehicle is stopped.

C0186 52

1. The ignition is ON.
2. The ignition voltage is greater than 8 volts.
3. DTC C0196 is not set.
4. The yaw rate is less than 8 degrees per second.

C0186 00

One of the following conditions exist

1. The lateral accelerometer sensor input voltage is less than 0.15 volts.
2. The lateral accelerometer sensor input voltage is greater than 4.85 volts for 0.03 seconds.

C0186 08

The lateral accelerometer voltage does not increase at least 0.5 volts during the lateral accelerometer sensor self test.

C0186 09

The lateral jerk exceeds 11 g per second twice within 0.2 seconds.

C0186 19

The lateral acceleration is greater than 0.5 g for more than 1 second.

C0186 1A

Both of the following conditions exist

1. The compensated bias value of the lateral accelerometer sensor is greater than 0.3 g.
2. The yaw rate is centered.

C0186 52

The slip rate error exceeds 0.5 g 60 times within one drive cycle.

1. The EBCM disables the VSES for the duration of the ignition cycle.
2. The DIC displays the Service Stabilitrak message.
3. The ABS/TCS remains functional.

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

The following conditions can cause this concern

1. Improper steering alignment.
2. Open, short to ground, or short to voltage.
3. Internal lateral accelerometer failure.
4. EBCM internal failure.

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

1. 2: Tests for the proper voltage output on the 5-volt reference circuit and the proper operation of the signal circuit.
2. 3: Tests for possible low 5-volt reference output or a problem with the signal circuit.
3. 4: Tests for a short to voltage on the 5-volt reference circuit. If a short to voltage exists, other DTCs may be set for the vehicle stability system.
4. 8: Tests for a problem with the low reference circuit. If a short to voltage exists, other DTCs may be set for the vehicle stability system.

DTC C0186

The longitudinal accelerometer is used to determine straight-line acceleration. This information is used when calculating the desired traction control in AWD applications.

This diagnostic procedure supports the following DTC

DTC C0192 All Wheel Drive (AWD)/Four Wheel Drive (4WD) Reference Accelerometer Circuit

This vehicle has DTCs which include DTC Symptoms. For more information on DTC Symptoms, refer to DTC Symptom Description in Vehicle DTC Information.

DTC C0192

1. The ignition is ON.
2. Ignition voltage is greater than 8 volts.

C0192 00

The code is set when the following conditions exist

1. The longitudinal sensor signal voltage is below 0.18 volt or above 4.84 volts for 30 milliseconds.
2. The longitudinal sensor does not pass an internal self check test when the ignition is turned ON.

C0192 1A

The longitudinal sensor is self calibrated for temperature changes. If the calibration bias exceeds 0.5 g, the DTC is set.

1. The traction control system (TCS) is degraded.
2. The TCS indicators turn ON.
3. The antilock brake system (ABS) remains functional.

Thoroughly inspect connections and wiring that may cause an intermittent malfunction. Refer to Testing for Electrical Intermittents , Wiring Repairs , and Connector Repairs in Wiring Systems.

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

1. 2: This step tests for the proper voltage output on the 5-volt reference circuit and the proper operation of the signal circuit.
2. 3: This step tests for possible low 5-volt reference output or a problem with the signal circuit.
3. 4: This step tests for a short to voltage on the 5-volt reference circuit. If a short to voltage exists, other DTCs may be set for the vehicle stability system if equipped.
4. 8: This step tests for a problem with the low reference circuit. If a short to voltage exists, other DTCs may be set for the vehicle stability system if equipped.

DTC C0192

The vehicle stability enhancement system (VSES) is activated by the electronic brake control module (EBCM) calculating the desired yaw rate and comparing it to the actual yaw rate input. The desired yaw rate is calculated from measured steering wheel position, vehicle speed, and lateral acceleration. The difference between the desired yaw rate and actual yaw rate is the yaw rate error, which is a measurement of oversteer or understeer. If the yaw rate error becomes too large, the EBCM will attempt to correct the vehicles yaw motion by applying differential braking to the left or right front wheel.

The amount of differential braking applied to the left or right front wheel is based on both the yaw rate error and side slip rate error. The side slip rate error is a function of the lateral acceleration minus the product of the yaw rate and vehicle speed. The yaw rate error and side slip rate error are combined to produce the total delta velocity error. When the delta velocity error becomes too large and the VSES system activates, the drivers steering inputs combined with the differential braking will attempt to bring the delta velocity error toward zero.

The VSES activations generally occur during aggressive driving, in the turns or bumpy roads without much use of the accelerator pedal. When braking during VSES activation, the brake pedal will feel different than the ABS pedal pulsation. The brake pedal pulsates at a higher frequency during VSES activation.

This diagnostic procedure supports the following DTC

DTC C0196 Yaw Rate Circuit

This vehicle has DTCs which include DTC Symptoms. For more information on DTC Symptoms, refer to DTC Symptom Description in Vehicle DTC Information.

DTC C0196

1. The ignition is ON.
2. The ignition voltage is greater than 8 volts.
3. The vehicle is stopped or the vehicle speed is greater than 45 km/h (28 mph).
4. The yaw rate isolation test runs with any of the following conditions: The brake pedal is not pressed. ABS is not active. The vehicle speed is greater than 8 km/h (5 mph). Lateral acceleration is less than 0.5 g. VSES is not active on undriven axle and TCS is active. AWD TCS is active.

C0196 00

One of the following conditions exist

1. The yaw rate sensor input voltage is less than 0.15 volts.
2. The yaw rate sensor input voltage is greater than 4.85 volts for 1 seconds.
3. The yaw rate input changes by more than 390 degrees/second per second.
4. The yaw rate bias exceeds 7 degrees/second.
5. The yaw rate error is greater than 5 degrees/second more than 30 times in one drive cycle.

1. The EBCM disables the VSES for the duration of the ignition cycle.
2. The DIC displays the Service Stabilitrak message.
3. The ABS/TCS remains functional.

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

1. Check the vehicle for proper steering alignment.
2. The Snapshot function on the scan tool can help find an intermittent DTC.

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

1. 3: Tests for the proper operation of the circuit in the low voltage range.
2. 4: Tests for the proper operation of the circuit in the high voltage range. If the fuse in the jumper opens when you perform this test, the signal circuit is shorted to ground.
3. 5: Tests for a short to voltage in the 5-volt reference circuit.
4. 6: Tests the bias voltage of the yaw rate sensor.

DTC C0196

The system relay is energized when the ignition is ON. The system relay supplies voltage to the valve relay. The electronic brake control module (EBCM) activates the valve relay to supply voltage to the valve solenoids. This voltage is referred to as the system voltage. The EBCM microprocessor activates individual valve solenoids by grounding the valve solenoid control circuits.

This diagnostic procedure supports the following DTCs

1. DTC C0220 Left Front Antilock Brake System (ABS) Channel in Release Too Long
2. DTC C0221 Right Front Antilock Brake System (ABS) Channel in Release Too Long
3. DTC C0228 Left Rear Antilock Brake System (ABS) Channel in Release Too Long
4. DTC C0229 Right Rear Antilock Brake System (ABS) Channel in Release Too Long

1. The ignition is ON.
2. The vehicle is experiencing an ABS event.

This code is set when the following criteria are met.

1. The EBCM is commanding a valve solenoid to release brake pressure.
2. The wheel that is commanded to release brake pressure has a speed below 5 km/h (3 mph) for 1.25 seconds.

If equipped, the following actions occur.

1. The EBCM disables ABS/TCS.
2. Adaptive cruise control (ACC) Braking is degraded.
3. Vehicle Stability Enhancement System (VSES) is disabled.
4. The ABS indicator turns ON.
5. The traction off indicator turns ON.

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

The solenoid valve circuit is internal to the EBCM. The solenoid valve circuit is not diagnosable external to the EBCM. The DTC sets when there is a malfunction in the solenoid circuit internal to the EBCM.

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

1. 2: Determines whether the DTC is current.

DTC C0220-C0229

The electronic brake control module (EBCM) and the powertrain control module (PCM) simultaneously control the traction control. The EBCM sends a serial data message to the PCM requesting torque reduction. When certain PCM DTCs are set, the PCM will not be able to perform the torque reduction for traction control. A serial data message is sent to the EBCM indicating that traction control is not allowed.

This diagnostic procedure supports the following DTC

DTC C0240 PCM Traction Control Not Allowed

1. The ignition is ON.
2. Ignition voltage is greater than 8 volts.

The PCM diagnoses the requested torque signal circuit and sends a serial data message to the EBCM indicating that torque reduction is not allowed.

1. The EBCM disables the EDC/TCS for the duration of the ignition cycle.
2. The Traction Off indicator turns ON.
3. 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.

This DTC is for information only. As an aid to the technician, this DTC indicates that there are no problems in the ABS/TCS system.

DTC C0240

The electronic brake control module (EBCM) and the powertrain control module (PCM) simultaneously control the traction control. The EBCM sends a serial data message to the PCM requesting torque reduction. When certain PCM DTCs are set, the PCM will not be able to perform the torque reduction for traction control. A serial data message is sent to the EBCM indicating that traction control is not allowed.

This diagnostic procedure supports the following DTC

DTC C0242 PCM Indicated TCS Malfunction

1. The ignition is ON.
2. Ignition voltage is greater than 8 volts.

The PCM diagnoses a condition preventing the engine control portion of the traction control function and sends a serial data message to the EBCM indicating that torque reduction is not allowed. The PCM will typically set a DTC and the EBCM will set this DTC.

If equipped, the following actions occur

1. The EBCM disables the Traction Control System (TCS) for the duration of the ignition cycle.
2. The Traction Control indicator turns ON.
3. The Antilock Brake System (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.

This DTC is for information only. As an aid to the technician, this DTC indicates that there are no problems in the ABS/TCS system.

DTC C0242

The electronic brake control module (EBCM) receives invalid information from other modules through serial data bus. The EBCM will set DTC based on this information.

This diagnostic procedure supports the following DTCs

1. DTC C0249 Left Normal Force Error
2. DTC CO250 Right Normal Force Error

This vehicle has DTCs which include DTC Symptoms. For more information on DTC Symptoms, refer to DTC Symptom Description in Vehicle DTC Information.

DTC C0249 or C0250

1. The ignition is ON.
2. Ignition voltage is greater than 8 volts.

The EBCM receives invalid information from other modules.

1. The EBCM operates normal.
2. The Antilock Brake System (ABS), Traction Control System (TCS), and Brake indicator lights remain OFF.

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

This DTC is for information only. As an aid to the technician, this DTC indicates that there are no problems in the ABS/TCS System.

DTC C0249 or C0250

The Vehicle Stability Enhancement System (VSES) is activated by the electronic brake control module (EBCM) calculating the desired yaw rate and comparing it to the actual yaw rate input. The desired yaw rate is calculated from measured steering wheel position, vehicle speed, and lateral acceleration. The difference between the desired yaw rate and actual yaw rate is the yaw rate error, which is a measurement of oversteer or understeer. If the yaw rate error becomes too large, the EBCM will attempt to correct the vehicles yaw motion by applying differential braking to the left or right front wheel.

The amount of differential braking applied to the left or right front wheel is based on both the yaw rate error and side slip rate error. The side slip rate error is a function of the lateral acceleration minus the product of the yaw rate and vehicle speed. The yaw rate error and side slip rate error are combined to produce the total delta velocity error. When the delta velocity error becomes too large and the VSES system activates, the drivers steering inputs combined with the differential braking will attempt to bring the delta velocity error toward zero.

The VSES activations generally occur during aggressive driving, in the turns or bumpy roads without much use of the accelerator pedal. When braking during VSES activation, the brake pedal will feel different than the Antilock Brake System (ABS) pedal pulsation. The brake pedal pulsates at a higher frequency during VSES activation.

This diagnostic procedure supports the following DTC

DTC C0252 VSES Sensors Uncorrelated

1. The steer angle has been centered.
2. The VSES is active.
3. The direction, understeer or oversteer, of the yaw rate error has not changed.
4. The centered lateral acceleration value is less than 0.5 g.
5. The yaw rate error is less than 6 degrees/second.
6. The side slip error is greater than 1.8 meters/second 2 .

One of the following conditions exists

1. The yaw rate error is greater than 10 degrees/second with the vehicle speed less than 60 km/h (37 mph) and the acceleration pedal is pressed more than 25 percent of the pedal travel range for 1 second during the VSES activation.
2. With the yaw rate less than 8 degrees/second, the side slip error is greater than 4.9 meters/second 2 for 5 seconds.

1. The EBCM disables the VSES for the duration of the ignition cycle.
2. The driver information center (DIC) displays the Service Stability message.
3. The ABS/Traction Control System (TCS) remains functional.

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

The following conditions can cause this concern

1. Improper steering alignment.
2. Open, short to ground, or short to voltage.
3. Internal lateral accelerometer failure.
4. EBCM internal failure.

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

1. 2: Perform the Steering Position Sensor Test in order to verify that the steering wheel position sensor (SWPS) is operating properly.
2. 3: Verify that the Lateral Accelerometer Signal parameter is within the valid range.
3. 4: Verify that the Yaw Rate Signal parameter is within the valid range.

DTC C0252

The usable output voltage range for the lateral accelerometer and yaw rate sensors is 0.25-4.75 volts. The scan tool will report zero lateral acceleration or yaw rate as 2.5 volts with no sensor bias present. The sensor bias compensates for sensor mounting alignment errors, electronic signal errors, temperature changes, and manufacturing differences.

This diagnostic procedure supports the following DTC

DTC C0253 Centering Error

The vehicle speed is greater than 40 km/h (25 mph).

The vehicle has been driven for 10 minutes without completing steer angle centering.

1. The EBCM disables the VSES for the duration of the ignition cycle.
2. The DIC displays the Service Stability System message.
3. The ABS/TCS remains functional.

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

The following conditions can cause this concern

1. Improper steering alignment.
2. Open, short to ground, or short to voltage.
3. Internal lateral accelerometer failure.
4. EBCM internal failure.

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

1. 2: Perform the Steering Position Sensor Test in order to verify that the steering wheel position sensor (SWPS) is operating properly.
2. 3: Verify that the Lateral Accelerometer Signal parameter is within the valid range.
3. 4: Verify that the Yaw Rate Signal parameter is within the valid range.

DTC C0253

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 operating software in the EBCM. The DRP uses active control with the existing ABS in order to regulate the vehicle's rear brake pressure.

This diagnostic procedure supports the following DTC

DTC C0281 DRP Performance

One or more faults have been detected by the EBCM in the ABS/TCS systems.

One of the following conditions exists

1. DTC C0121, C0113, C0114, C0115, C0900, or C0550 sets.
2. Two wheel speed sensor DTCs on the same axle set.

1. The EBCM disables the DRP for the duration of the ignition cycle.
2. The red 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.

This DTC is for information only. As an aid to the technician, this DTC indicates that another DTC exists that fails DRP.

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

1. 2: Verifies whether other ABS/TCS/VSES DTCs are set.

DTC C0281

The electronic brake control module (EBCM) detects an internal malfunction or loss of ground.

This diagnostic procedure supports the following DTC

DTC C0550 Electronic Control Unit Performance

The ignition switch is in the ON position.

1. An internal EBCM malfunction exists.
2. System voltage is less than half the ignition voltage continuously for 0.04 seconds.

If equipped, the following actions occur

1. The ABS/ACC/DRP/EDC/IVC/TPM/VES/VSES are disabled.
2. TCS is degraded.
3. The ABS/TCS indicators turn ON.
4. The red BRAKE Warning indicator turns ON.

The DIC displays the following

1. Service ABS
2. Service Traction System
3. Service Stabilitrak
4. Service Radar Cruise

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

Possible causes of this DTC

1. Open ground at the EBCM
2. Internal malfunction in the EBCM

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

1. 2: Tests for a proper ground to the EBCM.

DTC C0550

When the electronic brake control module (EBCM) is replaced, software and calibrations are flash programmed into the EBCM. The EBCM receives the vehicle powertrain options information from the powertrain control module (PCM) in order for the EBCM to automatically calibrate to the vehicle.

This diagnostic procedure supports the following DTC

DTC C0551 Option Configuration Error

1. The ignition is ON.
2. Ignition voltage is greater than 8 volts.

One or more of the following conditions are present

1. The incorrect EBCM is installed on the vehicle.
2. The incorrect software or calibrations have been flash programmed into the EBCM.

If equipped, the following actions occur

1. The EDC/TCS are disabled.
2. The TCS indicator turns ON.

The DIC displays the Service Traction System message.

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 DTC was set after EBCM replacement, verify that the replacement EBCM and software are correct for the vehicle.

DTC C0551

The electronic brake control module (EBCM) disables the traction control when other electronic control modules set DTCs for components that effect the operation of the traction control system.

This diagnostic procedure supports the following DTC

DTC C0561 System Disabled Information Stored

1. The ignition is ON.
2. Ignition voltage is greater than 8 volts.

The PCM or BCM diagnoses a condition preventing the engine control portion of the traction control function and sends a serial data message to the EBCM indicating that torque reduction is not allowed. The PCM or BCM will typically set a DTC and the EBCM will set this DTC.

1. The EBCM disables the TCS until the DTC becomes a history DTC.
2. The Traction Off indicator turns ON.
3. 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.

This DTC is for information only. As an aid to the technician, this DTC indicates that there are no problems in the ABS/TCS system.

DTC C0561

When the electronic brake control module (EBCM) is replaced, software and calibrations are flash programmed into the EBCM. The EBCM receives the vehicle identification number information from the vehicle in order for the EBCM to automatically calibrate to the vehicle.

This diagnostic procedure supports the following DTC

DTC C0565 Vehicle Identification Number (VIN) Information Error

1. The ignition is ON.
2. Ignition voltage is greater than 8 volts.

One or more of the following conditions are present

1. The incorrect EBCM is installed on the vehicle.
2. The incorrect software or calibrations have been flash programmed into the EBCM.

If equipped, the following actions occur

1. The EDC/TCS are disabled.
2. The TCS indicator turns ON.

The DIC displays the Service Traction System message.

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 DTC was set after EBCM replacement, verify that the replacement EBCM and software are correct for the vehicle.

DTC C0565

The steering wheel position sensor supplies 2 analog inputs, Phase A and Phase B, to the electronic brake control module (EBCM). The 2 input signals are approximately 90 degrees out of phase. By interpreting the relationship between the 2 inputs, the EBCM can determine the position of the steering wheel and the direction of the steering wheel rotation.

This diagnostic procedure supports the following DTC

DTC C0710 Steering Position Signal

This vehicle has DTCs which include DTC Symptoms. For more information on DTC Symptoms, refer to DTC Symptom Description in Vehicle DTC Information.

DTC C0710

C0710 00

1. The ignition is ON.
2. Ignition voltage is greater than 8 volts.
3. The steering wheel position sensor has been powered ON for 0.2 seconds.

C0710 1A

1. The ignition is ON.
2. Ignition voltage is greater than 8 volts.
3. The steering wheel position sensor is centered.

C0710 1F

1. The ignition is ON.
2. Ignition voltage is greater than 8 volts.
3. The steering wheel position sensor has been powered ON for 0.2 seconds.
4. The steering rate of Phase A is less than 80 degrees per second.

C0710 52

1. The ignition is ON.
2. Ignition voltage is greater than 8 volts.
3. The steering wheel position sensor has been powered ON for 0.2 seconds.
4. The steering wheel position sensor is centered.

C0710 00

Both Phase A and Phase B are greater than 4.9 volts or less than 0.2 volts for 1.6 seconds.

C0710 1A

The steering bias is greater than 40 degrees.

C0710 1F

The difference in the phase angle between Phase A and Phase B is greater than 106 degrees or less than 84 degrees continuously for 0.25 seconds.

C0710 52

The changes in Phase A or Phase B is greater than 36 degrees between consecutive scans of the signal.

1. The EBCM disables the vehicle stability enhancement system (VSES) for the duration of the ignition cycle.
2. The driver information center (DIC) displays the Service Stability System message.
3. 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. Check the vehicle for proper alignment. The car should not pull in either direction while driving straight on a level surface.
2. The Snapshot function on the scan tool can help find an intermittent DTC.
3. Possible causes for this DTC are the following conditions: One of the steering wheel position sensor inputs are open, shorted to ground, or shorted to battery. Internal steering wheel position sensor malfunction. Noise on the steering wheel position sensor signal lines. Yaw rate/lateral accelerometer sensor malfunction causing drifting signal outputs. Internal EBCM malfunction.

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

1. 2: Perform the Steering Position Sensor Test in order to verify if the steering wheel position sensor (SWPS) is operating properly.
2. 3: Tests for the proper operation of the steering wheel position signal A circuit in the low voltage range.
3. 4: Tests for the proper operation of the steering wheel position signal B circuit in the low voltage range.
4. 5: Tests for the proper operation of the steering wheel position signal A circuit in the high voltage range. If the fuse in the jumper opens when you perform this test, the signal circuit is shorted to ground.
5. 6: Tests for the proper operation of the steering wheel position signal B circuit in the high voltage range. If the fuse in the jumper opens when you perform this test, the signal circuit is shorted to ground.
6. 7: Tests for a short to voltage in the 5-volt reference circuit.
7. 8: Tests for a high resistance or an open in the low reference circuit.

DTC C0710

The electronic brake control module (EBCM) monitors the voltage level of the EBCMs case. If the voltage level is too high, damage may result in the system. When the EBCM detects a high voltage condition, the EBCM turns OFF the system relay which removes battery voltage from the solenoid valves and pump motor.

This diagnostic procedure supports the following DTC

DTC C0820 Device Ground Circuit

The ignition is ON.

The case voltage is greater than 2 volts for 0.1 seconds.

If equipped, the following actions occur

1. The EBCM disables the ABS/ACC/VSES for the duration of the ignition cycle.
2. The DRP and TCS are degraded.
3. The ABS indicator turns ON.
4. The Traction Control indicator turns ON.
5. The DIC displays the Service Stability System message.
6. The red 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.

Possible causes of this DTC are the following conditions

1. Internal short in the pump motor.
2. External battery supply shorted to case.
3. Internal EBCM battery supply shorted to case.

The pump motor is integral to the BPMV. The pump motor is not serviceable.

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

1. 3: Tests the ability of the EBCM to control the pump motor. If the test lamp illuminates, the pump motor circuit within the EBCM is good.

DTC C0820

The electronic brake control module (EBCM) supplies voltage to the brake pressure sensor, steering angle sensor, and yaw rate/lateral accelerometer sensor. This voltage is monitored by the EBCM for an over or under voltage condition.

This diagnostic procedure supports the following DTC

DTC C0870 Device Voltage Reference Output Circuit

1. The ignition is ON.
2. Ignition voltage is greater than 8 volts.

One of the follow conditions exists for 0.1 seconds

1. The sensor supply voltage is greater than 5.2 volts.
2. The sensor supply voltage is less than 4.8 volts.

1. The EBCM disables the VSES for the duration of the ignition cycle.
2. ACC braking function disabled.
3. TCS is degraded.
4. The Traction Control and Active Handling indicator turns ON.
5. The DIC displays the Service Active Handling message.

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 following conditions can cause this concern

1. The sensor supply circuit is open, shorted to ground, or shorted to battery.
2. Internal sensor malfunction.
3. Internal EBCM malfunction.

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

1. 5: Tests for a short at the brake pressure sensor.
2. 6: Tests for a short at the steering wheel position sensor.
3. 7: Tests for a short at the yaw rate/lateral accelerometer sensor.

DTC C0870

The electronic brake control module (EBCM) monitors the voltage level available for system operation. A low voltage condition prevents the system from operating properly.

This diagnostic procedure supports the following DTC

DTC C0899 Device Voltage Low

1. The vehicle speed is greater than 8 km/h (5 mph).
2. The system relay is commanded ON.

One of the following conditions exists for 0.72 seconds

1. During initialization or when the system is inactive, the system voltage is less than 10.8 volts.
2. During the system operation, the system voltage is less than 9.0 volts.

If equipped, the following actions occur

1. The EBCM disables the ABS/ACC/VES/VSES for the duration of the ignition cycle.
2. The ABS indicator turns ON.
3. The traction control indicator turns ON.
4. The driver information center (DIC) displays the Service Stabilitrak and Service ABS messages.
5. DRP and traction control system (TCS) are degraded.

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

1. Test the charging system. Refer to «Diagnostic System Check - Vehicle»(/cadillac/sts/i-2004-2007/remont/oem-general-information/#vehicle-dtc-information) in Vehicle DTC Information.
2. Possible causes of this DTC are the following conditions: A charging system malfunction An excessive battery draw A weak battery A faulty system ground

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

1. 2: Use the scan tool in order to inspect the voltage to the EBCM.
2. 3: Use the scan tool in order to inspect the voltage to the body control module (BCM). A low voltage value in multiple modules indicates a concern in the charging system.
3. 5: Verifies that the condition is still present.

DTC C0899

The electronic brake control module (EBCM) monitors the voltage level available for system operation. If the voltage level is too high, damage may result in the system. When the EBCM detects a high voltage condition, the EBCM turns OFF the system relay which removes battery voltage from the solenoid valves and pump motor.

This diagnostic procedure supports the following DTC

DTC C0900 Device Voltage High

The vehicle speed is greater than 8 km/h (5 mph).

The system voltage is greater than 17 volts for 0.72 seconds.

If equipped, the following actions occur

1. The EBCM disables the antilock brake system (ABS)/traction control system (TCS)/vehicle stability enhancement system (VSES) for the duration of the ignition cycle.
2. The DRP does not function optimally.
3. The ABS indicator turns ON.
4. The Traction Control and Active Handling indicator turns ON.
5. The driver information center (DIC) displays the following messages: Service ABS Service Traction System Service Active Handling

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

A possible cause of this DTC is overcharging.

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

1. 2: Use the scan tool in order to inspect the voltage to the EBCM.
2. 3: Use the scan tool in order to inspect the voltage to the body control module (BCM). A high voltage value in multiple modules indicates a concern in the charging system.
3. 4: Verifies that the condition is still present.

DTC C0900

Symptoms - Antilock Brake System

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/sts/i-2004-2007/remont/oem-general-information/#vehicle-dtc-information) in Vehicle DTC Information before using the Symptom Tables in order to verify that all of the following are true: There are no DTCs set. The control module(s) can communicate via the serial data link.
2. Review the system operation in order to familiarize yourself with the system functions. Refer to «ABS Description and Operation»(/cadillac/sts/i-2004-2007/remont/anti-locktraction-control/#antilock-brake-system-traction-control-system-stability-control-system) .

Visual/Physical Inspection

1. Inspect for aftermarket devices which could affect the operation of the antilock brake system. Refer to «Checking Aftermarket Accessories»(/cadillac/sts/i-2004-2007/remont/body-electrical/#wiring-systems-electrical-power-management-introduction__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 brake 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»(/cadillac/sts/i-2004-2007/remont/anti-locktraction-control/#antilock-brake-system-traction-control-system-stability-control-system)
2. «ABS Indicator Inoperative»(/cadillac/sts/i-2004-2007/remont/anti-locktraction-control/#antilock-brake-system-traction-control-system-stability-control-system)
3. «Traction Control Indicator Always On»(/cadillac/sts/i-2004-2007/remont/anti-locktraction-control/#antilock-brake-system-traction-control-system-stability-control-system)
4. «Traction Control Indicator Inoperative»(/cadillac/sts/i-2004-2007/remont/anti-locktraction-control/#antilock-brake-system-traction-control-system-stability-control-system)
5. «Traction Off Indicator Inoperative»(/cadillac/sts/i-2004-2007/remont/anti-locktraction-control/#antilock-brake-system-traction-control-system-stability-control-system)
6. «Vehicle Stability Enhancement System Inoperative»(/cadillac/sts/i-2004-2007/remont/anti-locktraction-control/#antilock-brake-system-traction-control-system-stability-control-system)
7. «Vehicle Stability Enhancement System Unwanted Activation»(/cadillac/sts/i-2004-2007/remont/anti-locktraction-control/#antilock-brake-system-traction-control-system-stability-control-system)
8. «Vehicle Stability Enhancement System Excessive Brake Pulsation»(/cadillac/sts/i-2004-2007/remont/anti-locktraction-control/#antilock-brake-system-traction-control-system-stability-control-system)

The instrument cluster controls the operation of the Antilock Brake System (ABS) indicator. The electronic brake control module (EBCM) reports the desired status of the ABS indicator via serial data messages. The EBCM supplies ground through the circuit when the ABS is operating properly. When there is a problem with ABS that should turn on the ABS indicator, the EBCM opens the ABS indicator signal circuit. Using the serial data messages the instrument cluster decides whether to turn on the ABS indicator.

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

1. 3: Use the scan tool to check the normal state of the ABS indicator control circuit.
2. 4: Ensures that the instrument panel cluster (IPC) can operate the ABS indicator.

ABS Indicator Always On

The instrument cluster controls the operation of the Antilock Brake System (ABS) indicator. The electronic brake control module (EBCM) reports the desired status of the ABS indicator via serial data messages. The EBCM supplies ground through the circuit when the ABS is operating properly. When there is a problem with ABS that should turn on the ABS indicator, the EBCM opens the ABS indicator signal circuit. Using the serial data messages the instrument cluster decides whether to turn on the ABS indicator.

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

1. 3: Use the scan tool to check the normal state of the ABS indicator control circuit.
2. 4: Ensures that the instrument panel cluster (IPC) can operate the ABS indicator.

ABS Indicator Inoperative

The Traction Control indicator is controlled by the instrument cluster (IPC) via serial data messages from the EBCM. The EBCM send a serial data message to the IPC to illuminate the Traction Control indicator when the EBCM has disabled TCS due to a DTC. The Traction Control indicator will also turn ON during the instrument cluster bulb check. When the ignition switch is turned to ON, the Traction Control indicator will turn ON for approximately 3 seconds and then turn OFF.

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

1. 2: Use the scan tool to check the normal state of the Traction Control indicator control.
2. 3: Ensures that the instrument cluster can operate the Traction Control indicator.

Traction Control Indicator Always On

The Traction Control indicator is controlled by the instrument cluster (IPC) via serial data messages from the EBCM. The EBCM send a serial data message to the IPC to illuminate the Traction Control indicator when the EBCM has disabled TCS due to a DTC. The Traction Control indicator will also turn ON during the instrument cluster bulb check. When the ignition switch is turned to ON, the Traction Control indicator will turn ON for approximately 3 seconds and then turn OFF.

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

1. 2: Use the scan tool to check the normal state of the Traction Control indicator control.
2. 3: Ensures that the instrument cluster can operate the Traction Control indicator.

Traction Control Indicator Inoperative

The Traction Off indicator is controlled by the instrument cluster via serial data messages from the EBCM. When the RIM sees the traction control switch input grounded through the momentary traction control switch, it sends a serial data 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 serial data message to the instrument cluster to turn on the Traction Off indicator on the instrument panel. Each time the ignition is cycled from OFF to ON, the traction control system is enabled.

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

1. 2: Use the scan tool to check the normal state of the Traction Off indicator control.
2. 3: Ensures that the instrument cluster can operate the Traction Off indicator.

Traction Off Indicator Always On

The Traction Off indicator is controlled by the instrument cluster via serial data messages from the electronic brake control module (EBCM). When the rear integration module (RIM) sees the traction control switch input grounded through the momentary traction control switch, it sends a serial data 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 serial data message to the instrument cluster to turn ON the Traction Off indicator on the instrument panel. Each time the ignition is cycled from OFF to ON, the traction control system is enabled.

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

1. 2: Use the scan tool to check the normal state of the Traction Off control.
2. 3: This step ensures that the instrument cluster can operate the Traction Off indicator.

Traction Off Indicator Inoperative

The vehicle stability enhancement system (VSES) is activated by the electronic brake control module (EBCM) calculating the desired yaw rate and comparing it to the actual yaw rate input. The desired yaw rate is calculated from measured steering wheel position, vehicle speed, and lateral acceleration. The difference between the desired yaw rate and actual yaw rate is the yaw rate error, which is a measurement of oversteer or understeer. If the yaw rate error becomes too large, the EBCM will attempt to correct the vehicle's yaw motion by applying differential braking to the left or right front wheel.

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

1. 3: Perform the Steering Position Sensor Test in order to verify if the steering wheel position sensor (SWPS) is operating properly.
2. 4: Verify that the Lateral Accelerometer Input parameter is within the valid range.
3. 5: Verify that the Yaw Rate Input parameter is within the valid range.

Vehicle Stability Enhancement System Inoperative

The vehicle stability enhancement system (VSES) is activated by the electronic brake control module (EBCM) calculating the desired yaw rate and comparing it to the actual yaw rate input. The desired yaw rate is calculated from measured steering wheel position, vehicle speed, and lateral acceleration. The difference between the desired yaw rate and actual yaw rate is the yaw rate error, which is a measurement of oversteer or understeer. If the yaw rate error becomes too large, the EBCM will attempt to correct the vehicle's yaw motion by applying differential braking to the left or right front wheel.

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

1. 6: Perform the Steering Position Sensor Test in order to verify if the steering wheel position sensor (SWPS) is operating properly.

Vehicle Stability Enhancement System Unwanted Activation

The vehicle stability enhancement system (VSES) is activated by the electronic brake control module (EBCM) calculating the desired yaw rate and comparing it to the actual yaw rate input. The desired yaw rate is calculated from measured steering wheel position, vehicle speed, and lateral acceleration. The difference between the desired yaw rate and actual yaw rate is the yaw rate error, which is a measurement of oversteer or understeer. If the yaw rate error becomes too large, the EBCM will attempt to correct the vehicle's yaw motion by applying differential braking to the left or right front wheel.

Vehicle Stability Enhancement System Excessive Brake Pulsation

ABS Automated Bleed Procedure

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

The ABS Automated Bleed Procedure uses a scan tool to cycle the system solenoid valves and run the pump in order to purge any air from the secondary circuits. These 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 in these circuits to flow out toward the brake corners.

Performing the Automated Bleed Procedure

1. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/cadillac/sts/i-2004-2007/remont/hoistjack/#general-information) in General Information.
2. Remove all four tire and wheel assemblies. Refer to «Tire and Wheel Removal and Installation»(/cadillac/sts/i-2004-2007/remont/wheel-tire-system/#tires-and-wheels) in Tires and Wheels.
3. Inspect the brake system for leaks and visual damage. Refer to «Symptoms - Hydraulic Brakes»(/cadillac/sts/i-2004-2007/remont/mechanical-hydraulic/#hydraulic-brake-system__symptoms-hydraulic-brakes) in Hydraulic Brakes. Repair or replace components as needed.
4. Lower the vehicle.
5. Inspect the battery state of charge. Refer to «Battery Inspection/Test»(/cadillac/sts/i-2004-2007/remont/charging-system/#battery-charging-system-and-starting-system) in Engine Electrical.
6. Install a scan tool.
7. Turn the ignition ON, with the engine OFF.
8. With the scan tool, establish communications with the ABS system. Select Special Functions. Select Automated Bleed from the Special Functions menu.
9. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/cadillac/sts/i-2004-2007/remont/hoistjack/#general-information) in General Information.
10. Following the directions given on the scan tool, pressure bleed the base brake system. Refer to «Hydraulic Brake System Bleeding (Manual)»(/cadillac/sts/i-2004-2007/remont/mechanical-hydraulic/#hydraulic-brake-system) or «Hydraulic Brake System Bleeding (Pressure)»(/cadillac/sts/i-2004-2007/remont/mechanical-hydraulic/#hydraulic-brake-system) in Hydraulic Brakes.
11. Follow the scan tool directions until the desired brake pedal height is achieved.
12. If the bleed procedure is aborted, a malfunction exists. Perform the following steps before resuming the bleed procedure: If a DTC is detected, refer to «Diagnostic Trouble Code (DTC) List - Vehicle»(/cadillac/sts/i-2004-2007/remont/oem-general-information/#vehicle-dtc-information__diagnostic-trouble-code-dtc-list) in Vehicle DTC Information, and diagnose the appropriate DTC. If the brake pedal feels spongy, perform the conventional brake bleed procedure again. Refer to «Hydraulic Brake System Bleeding (Manual)»(/cadillac/sts/i-2004-2007/remont/mechanical-hydraulic/#hydraulic-brake-system) «Hydraulic Brake System Bleeding (Pressure)»(/cadillac/sts/i-2004-2007/remont/mechanical-hydraulic/#hydraulic-brake-system) in Hydraulic Brakes.
13. When the desired pedal height is achieved, press the brake pedal to inspect for firmness.
14. Lower the vehicle.
15. Remove the scan tool.
16. Install the tire and wheel assemblies. Refer to «Tire and Wheel Removal and Installation»(/cadillac/sts/i-2004-2007/remont/wheel-tire-system/#tires-and-wheels) in Tires and Wheels.
17. Inspect the brake fluid level. Refer to «Master Cylinder Reservoir Filling»(/cadillac/sts/i-2004-2007/remont/mechanical-hydraulic/#hydraulic-brake-system__master-cylinder-reservoir-filling) in Hydraulic Brakes.
18. Road test the vehicle while inspecting that the pedal remains high and firm.

Removal Procedure

1. Turn OFF the ignition.
2. Raise and support vehicle. Refer to «Lifting and Jacking the Vehicle»(/cadillac/sts/i-2004-2007/remont/hoistjack/#general-information) in General Information.
3. Remove the air deflector shield. Refer to «Air Deflector Replacement - Front»(/cadillac/sts/i-2004-2007/remont/exterior-body-panels/#body-front-end) in Body Front End.
4. Remove the right front wheelhouse liner. Refer to «Fender, Fender Insulator, Wheelhouse Liner Replacement - Front»(/cadillac/sts/i-2004-2007/remont/exterior-body-panels/#body-front-end) in Body Front End.
5. Remove the washer solvent container bracket. Refer to «Solvent Container, Pump, Level Sensor Replacement - Windshield Washer»(/cadillac/sts/i-2004-2007/remont/wiperwasher-systems/#wiper-system-and-washer-system) in Wipers/Washer Systems.
6. Thoroughly clean all of the contaminants from and around the EBCM assembly.
7. Press the retainer on the EBCM electrical connector (1).
8. Rotate the EBCM connector tab (2) forward to the unlocked position.
9. Disconnect the EBCM electrical connector (1) from the EBCM and position out of the way.
10. Remove and discard the 4 EBCM to brake pressure modulator valve (BPMV) screws (1).
11. Clean the surface of the EBCM/BPMV assembly.
12. Separate the EBCM (1) from the BPMV (2).

Installation Procedure

1. Clean the seal surface of the BPMV (2).
2. Install the EBCM (1) to the BPMV (2).
3. Make sure that the internal pump motor connector (3) is installed into the new EBCM (1) prior to EBCM replacement.
4. Install the 4 NEW EBCM to BPMV screws. Tighten: Tighten the 4 NEW EBCM to BPMV screws in sequence (1-4) to 5 N.m (44 lb in).
5. Connect the EBCM electrical connector (1) to the EBCM (3).
6. Rotate the EBCM connector tab (2) rearward to the locked position.
7. Install the washer solvent container bracket. Refer to «Solvent Container, Pump, Level Sensor Replacement - Windshield Washer»(/cadillac/sts/i-2004-2007/remont/wiperwasher-systems/#wiper-system-and-washer-system) in Wipers/Washer Systems.
8. Install the wheelhouse liner. Refer to «Fender, Fender Insulator, Wheelhouse Liner Replacement - Front»(/cadillac/sts/i-2004-2007/remont/exterior-body-panels/#body-front-end) in Body Front End.
9. Install the air deflector shield. Refer to «Air Deflector Replacement - Front»(/cadillac/sts/i-2004-2007/remont/exterior-body-panels/#body-front-end) in Body Front End.
10. Lower the vehicle.
11. Use the scan tool in order to clear the DTCs.
12. If installing a new EBCM it is necessary to program the EBCM. Refer to «Service Programming System (SPS)»(/cadillac/sts/i-2004-2007/remont/communication-devices/#programming-and-setup-all-systems__service-programming-system-sps) in Programming and Setup.
13. Perform the Diagnostic System Check - Vehicle. Refer to «Diagnostic System Check - Vehicle»(/cadillac/sts/i-2004-2007/remont/oem-general-information/#vehicle-dtc-information) in Vehicle DTC Information.
14. Recalibrate the brake pedal position sensor. Refer to «Brake Pedal Position Sensor Replacement»(/cadillac/sts/i-2004-2007/remont/exterior-lights/#lighting-systems-introduction) in Lighting Systems.

Brake Pressure Modulator Valve (BPMV) Replacement

1. Turn OFF the ignition.
2. Thoroughly clean all contaminants from around the EBCM.
3. Remove the 2 master cylinder brake pipes (3) from the BPMV (1).
4. Clean any brake fluid spillage from the BPMV (1).
5. Raise and support vehicle. Refer to «Lifting and Jacking the Vehicle»(/cadillac/sts/i-2004-2007/remont/hoistjack/#general-information) in General Information.
6. Remove the air deflector shield. Refer to «Air Deflector Replacement - Front»(/cadillac/sts/i-2004-2007/remont/exterior-body-panels/#body-front-end) in Body Front End.
7. Remove the wheelhouse liner. Refer to «Fender, Fender Insulator, Wheelhouse Liner Replacement - Front»(/cadillac/sts/i-2004-2007/remont/exterior-body-panels/#body-front-end) in Body Front End.
8. Remove the washer solvent container bracket. Refer to «Solvent Container, Pump, Level Sensor Replacement - Windshield Washer»(/cadillac/sts/i-2004-2007/remont/wiperwasher-systems/#wiper-system-and-washer-system) in Wipers/Washer Systems.
9. Remove the 4 wheel brake pipes (2) from the BPMV (1).
10. Press the retainer on the EBCM electrical connector (1).
11. Rotate the EBCM connector tab (2) forward to the unlocked position.
12. Disconnect the EBCM electrical connector (1) from the EBCM and position out of the way.
13. Remove the front BPMV bracket nuts.
14. Remove the EBCM/BPMV assembly (1) from the BPMV bracket.
15. Remove and discard the 4 EBCM to BPMV screws.
16. Clean the surface of the EBCM/BPMV assembly.
17. Remove the EBCM (1) from the BPMV (2).

1. Clean the seal surface of the BPMV.
2. Install the EBCM (1) to the BPMV (2).
3. Make sure that the internal pump motor connector (3) is installed into the new EBCM (1) prior to EBCM replacement.
4. Install the 4 NEW EBCM to BPMV screws. Tighten: Tighten the 4 NEW EBCM to BPMV screws in sequence (1-4) to 5 N.m (44 lb in).
5. Install the EBCM/BPMV assembly (1) to the BPMV bracket.
6. Install the BPMV bracket nuts (2). Tighten: Tighten the BPMV nuts to 10 N.m (89 lb in).
7. Connect the EBCM electrical connector (1) to the EBCM (2).
8. Rotate the EBCM connector tab (2) rearward to the locked position.
9. Install the 4 wheel brake pipes (2) to the BPMV (1) using the locations recorded during the removal procedure. Tighten: Tighten the wheel brake pipes to 27 N.m (20 lb ft).
10. Install the washer solvent container bracket. Refer to «Solvent Container, Pump, Level Sensor Replacement - Windshield Washer»(/cadillac/sts/i-2004-2007/remont/wiperwasher-systems/#wiper-system-and-washer-system) in Wipers/Washer Systems.
11. Install the wheelhouse liner. Refer to «Fender, Fender Insulator, Wheelhouse Liner Replacement - Front»(/cadillac/sts/i-2004-2007/remont/exterior-body-panels/#body-front-end) in Body Front End.
12. Install the air deflector shield. Refer to «Air Deflector Replacement - Front»(/cadillac/sts/i-2004-2007/remont/exterior-body-panels/#body-front-end) in Body Front End.
13. Lower the vehicle.
14. Install the 2 master cylinder brake pipes (3) to the BPMV (1) using the locations recorded during the removal procedure. Tighten: Tighten the master cylinder brake pipes to 27 N.m (20 lb ft).
15. If equipped with a brake fluid pressure sensor (4), connect the electrical connector.
16. Fill and bleed the hydraulic brake system. Refer to «Master Cylinder Reservoir Filling»(/cadillac/sts/i-2004-2007/remont/mechanical-hydraulic/#hydraulic-brake-system__master-cylinder-reservoir-filling) and «Hydraulic Brake System Bleeding (Manual)»(/cadillac/sts/i-2004-2007/remont/mechanical-hydraulic/#hydraulic-brake-system) or «Hydraulic Brake System Bleeding (Pressure)»(/cadillac/sts/i-2004-2007/remont/mechanical-hydraulic/#hydraulic-brake-system) in Hydraulic Brakes.
17. Perform the Auto Bleed Procedure. Refer to «ABS Automated Bleed Procedure»(/cadillac/sts/i-2004-2007/remont/anti-locktraction-control/#antilock-brake-system-traction-control-system-stability-control-system__abs-automated-bleed-procedure) .
18. Perform the System Check-Vehicle. Refer to «Diagnostic System Check - Vehicle»(/cadillac/sts/i-2004-2007/remont/oem-general-information/#vehicle-dtc-information) in Vehicle DTC Information.

1. Thoroughly clean all contaminants from around the EBCM.
2. Disconnect the brake fluid pressure sensor electrical connector (3) from the brake fluid pressure sensor (2).
3. Remove the brake fluid pressure sensor (2) from the EBCM (1).

1. Install the brake fluid pressure sensor (2) to the EBCM (1). Tighten: Tighten the brake fluid pressure sensor to 17 N.m (13 lb ft).
2. Connect the brake fluid pressure sensor electrical connector (3) to the brake fluid pressure sensor (2).
3. Fill and bleed the hydraulic brake system. Refer to «Master Cylinder Reservoir Filling»(/cadillac/sts/i-2004-2007/remont/mechanical-hydraulic/#hydraulic-brake-system__master-cylinder-reservoir-filling) and «Hydraulic Brake System Bleeding (Manual)»(/cadillac/sts/i-2004-2007/remont/mechanical-hydraulic/#hydraulic-brake-system) or «Hydraulic Brake System Bleeding (Pressure)»(/cadillac/sts/i-2004-2007/remont/mechanical-hydraulic/#hydraulic-brake-system) in Hydraulic Brakes.
4. Perform the Auto Bleed Procedure. Refer to «ABS Automated Bleed Procedure»(/cadillac/sts/i-2004-2007/remont/anti-locktraction-control/#antilock-brake-system-traction-control-system-stability-control-system__abs-automated-bleed-procedure) .
5. Perform the Diagnostic System Check - Vehicle. Refer to «Diagnostic System Check - Vehicle»(/cadillac/sts/i-2004-2007/remont/oem-general-information/#vehicle-dtc-information) in Vehicle DTC Information.

1. Remove the console shift lever bezel. Refer to «Console Shift Lever Bezel Replacement»(/cadillac/sts/i-2004-2007/remont/gauges-instrument-panels/#instrument-panel-system-displays-gauges-and-console) in Instrument Panel, Gages, and Console.
2. Disconnect the traction control electrical connector.
3. Remove the trim plate.
4. Remove the two traction control mounting screws (1).
5. Remove the traction control switch (2).

1. Install the traction control switch (2) to the trim plate.
2. Install the two traction control mounting screws (1). Tighten: Tighten the two traction control mounting screws to 2 N.m (18 lb in).
3. Connect the traction control electrical connector.
4. Install the console shift lever bezel. Refer to «Console Shift Lever Bezel Replacement»(/cadillac/sts/i-2004-2007/remont/gauges-instrument-panels/#instrument-panel-system-displays-gauges-and-console) in Instrument Panel, Gages, and Console.

1. Turn OFF the ignition.
2. To access the yaw rate sensor/lateral accelerometer move the passenger seat rearward.
3. Carefully lift the carpet by the seam.
4. Remove the 2 yaw rate sensor/lateral accelerometer mounting nuts (2).
5. Disconnect the yaw rate sensor/lateral accelerometer electrical connector (2) from the yaw rate sensor/lateral accelerometer.
6. Remove the yaw rate sensor/lateral accelerometer (1).

1. Install the yaw rate sensor/lateral accelerometer (1).
2. Install the 2 yaw rate sensor/lateral accelerometer nuts (2). Tighten: Tighten the yaw rate sensor/lateral accelerometer mounting nuts to 9 N.m (80 lb in).
3. Connect the yaw rate sensor/lateral accelerometer electrical connector (2) to the yaw rate sensor/lateral accelerometer (1).
4. Perform the System Check-Vehicle. Refer to «Diagnostic System Check - Vehicle»(/cadillac/sts/i-2004-2007/remont/oem-general-information/#vehicle-dtc-information) in Vehicle DTC Information.

1. Turn OFF the ignition.
2. To access the yaw rate sensor/lateral and longitudinal accelerometer move the passenger seat rearward.
3. Carefully lift the carpet by the seam.
4. Remove the 2 yaw rate sensor/lateral and longitudinal accelerometer mounting nuts (2).
5. Disconnect the yaw rate sensor/lateral and longitudinal accelerometer electrical connector (2) from the yaw rate sensor/lateral and longitudinal accelerometer.
6. Remove the yaw rate sensor/lateral and longitudinal accelerometer (1).

1. Install the yaw rate sensor/lateral and longitudinal accelerometer (1).
2. Install the 2 yaw rate sensor/lateral and longitudinal accelerometer nuts (2). Tighten: Tighten the yaw rate sensor/lateral and longitudinal accelerometer mounting nuts to 9 N.m (80 lb in).
3. Connect the yaw rate sensor/lateral and longitudinal accelerometer electrical connector (2) to the yaw rate sensor/lateral and longitudinal accelerometer (1).
4. Perform the System Check-Vehicle. Refer to «Diagnostic System Check - Vehicle»(/cadillac/sts/i-2004-2007/remont/oem-general-information/#vehicle-dtc-information) in Vehicle DTC Information.

Scheme 11

Scheme 12

This vehicle is equipped with the DBC7.2 antilock braking system.

The vehicle is equipped with the following braking systems

1. Antilock Brake System (ABS)
2. Engine Drag Control (EDC)
3. Dynamic Rear Proportioning (DRP)
4. Traction Control System (TCS)
5. Vehicle Stability Enhancement System (VSES) (w/JL4)

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 (one per drive wheel) Prime Valves (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 - 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.
6. Lateral Accelerometer Sensor (w/JL4) - The EBCM uses the lateral accelerometer sensor as an indication of the lateral acceleration of the vehicle.
7. Yaw Rate Sensor (w/JL4) - The EBCM uses the yaw rate sensor as an indication of the yaw rate of the vehicle.
8. Steering Wheel Position Sensor (SWPS) (w/JL4) - The EBCM uses the SWPS as an indication of the position and rotation of the steering wheel.

Initialization Sequence

The EBCM performs 1 initialization test each ignition cycle. The initialization of the EBCM occurs when 1 set of the following conditions occur

Both of the following conditions occur

1. The EBCM detects that there is a minimum of 500 RPM from the ECM via a serial data message.
2. The stop lamp 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 stop lamp 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.

Engine Drag Control (EDC)

When the driver releases the throttle, and the drag from the engine overcomes the frictional force between the tire and the road, EDC becomes active.

The EBCM sends a torque request signal to the ECM, which increases the torque at the wheels. This stabilizes the wheels by reducing the slip at the driven wheels.

When EDC is active, the driven wheels are controlled to a target below the non-driven wheels.

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 electronic brake control module (EBCM) will enter traction control mode.

First, the EBCM requests the engine control module (ECM) to reduce the amount of torque to the drive wheels via the serial data. The ECM reduces torque to the drive wheels by retarding spark timing and turning off fuel injectors. The ECM reports the amount torque delivered to the drive wheels via the serial data 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 instrument panel cluster (IPC) illuminates the Antilock Brake System (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 serial data 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 5 seconds.
3. The IPC detects a loss of serial data communications with the EBCM.

TRAC OFF

The instrument panel cluster (IPC) illuminates the TRAC OFF indicator when the following occurs

1. The electronic brake control module (EBCM) inhibits the traction control system due to a malfunction in the traction control system. The IPC receives a serial data message from the EBCM requesting illumination.
2. The rear integration module (RIM) detects that the traction control switch has been pressed (signal circuit is low). The rear integration module (RIM) sends a serial data message to the EBCM in order to disable traction control. The IPC receives a serial data message from the EBCM requesting illumination. The RIM sends a serial data message to the radio in order to activate an audible warning.

Vehicle Stability Enhancement System (VSES)

The vehicle stability enhancement system (VSES) adds an additional level of vehicle control to the EBCM.

Yaw rate is the rate of rotation about the vehicle's vertical axis. The VSES is activated when the EBCM determines that the desired yaw rate does not match the actual yaw rate as measured by the yaw rate sensor.

The desired yaw rate is calculated from the following parameters

1. The position of the steering wheel
2. The speed of the vehicle
3. The lateral, or sideways acceleration of the vehicle

The difference between the desired yaw rate and the actual yaw rate is the yaw rate error, which is a measurement of oversteer or understeer. If the yaw rate error becomes too large, the EBCM attempts to correct the vehicle's yaw motion by applying differential braking to the appropriate wheel. The amount of differential braking applied to the left or right front wheel is based on both the yaw rate error and side slip rate error.

The VSES activations generally occur during aggressive driving, in turns or on bumpy roads without much use of the accelerator pedal. When braking during VSES activation, the pedal pulsations feel different than the ABS pedal pulsations. The brake pedal pulsates at a higher frequency during VSES activation.

Special Tools

Special Tools Illustration Tool Number/ Description J 39700 Universal Pinout Box J 39700-300 Cable Adapter

See also:
• Diagnostic System Check - Vehicle
• Diagnostic Trouble Code (DTC) List - Vehicle
• DTC Symptom Description
• Lifting and Jacking the Vehicle
• Testing for Intermittent Conditions and Poor Connections
• Connector Repairs
• Circuit Testing
• Wiring Repairs
• Wheel Bearing/Hub Replacement - Front (AWD)
• Wheel Bearing/Hub Replacement - Rear
• Control Module References
• Exterior Lights Schematics
• Lighting Systems Connector End Views
• Computer/Integrating Systems Connector End Views
• Testing for Electrical Intermittents
• Steering Wheel Position Sensor or Steering Shaft Lower Bearing Replacement
• Checking Aftermarket Accessories
• Instrument Panel, Gages, and Console Connector End Views
• Measuring Wheel Alignment
• Power Steering Gear Replacement
• Brake Fluid Irritant Caution
• Brake Fluid Effects on Paint and Electrical Components Notice
• Hydraulic Brake System Bleeding (Manual)
• Tire and Wheel Removal and Installation
• Symptoms - Hydraulic Brakes
• Battery Inspection/Test
• Master Cylinder Reservoir Filling
• Air Deflector Replacement - Front
• Solvent Container, Pump, Level Sensor Replacement - Windshield Washer
• Fastener Notice
• Service Programming System (SPS)
• Brake Dust Caution
• Console Shift Lever Bezel Replacement
• ABS Automated Bleed Procedure
• ABS Schematics
• ABS Connector End Views
• Brake Pressure Modulator Valve (BPMV) Replacement
• Special Tools
• Scan Tool Output Controls
• Diagnostic Test Drive