C1996
Anti-Lock Control
Pinpoint Test I: DTC C1996
Normal Operation
The ABS module uses information received from several sensors (wheel speed sensors, steering wheel rotation sensor, stability control sensors, etc.) to determine if a vehicle instability event is about to occur. If an event is going to occur, the ABS module adjusts brake torque at specific wheels and the PCM reduces engine torque to make the vehicle more stable. Once the ABS module has determined that the stability event has been corrected, it returns brake and engine torque to normal and continues to monitor the vehicle.
- DTC C1996 (Active Yaw and/or Roll Control Disabled)- The ABS module monitors the stability event and is programmed to set DTC C1996 and disable the stability control system if the stability event lasts longer than 15 seconds.
This pinpoint test is intended to diagnose the following:
- Steering wheel rotation sensor
- Stability control sensor
- Wheel speed sensors
- ABS module
- Restraints Control Module (RCM)
PINPOINT TEST I : DTC C1996
I1 CHECK FOR ABS MODULE DTCs
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: Self-Test- ABS Module.
Are ABS DTCs C1233, C1234, C1235 or C1236 present?
Yes
GO to Pinpoint Test P. Pinpoint Test P: Unintended ABS Activation, ABS Too Sensitive, ABS Activates On a Normal Stop
No
GO to I2.
I2 CHECK THE ABS MODULE YAW RATE (YAW_RATE) PID
- Enter the following diagnostic mode on the scan tool: DataLogger- ABS Module.
- NOTE: The vehicle must be on level ground and at a complete standstill. Any vehicle movement results in false values for this test.
Monitor the YAW_RATE PID.
Is the YAW_RATE PID value between -0.05 and 0.05?
Yes
GO to I3.
No
GO to I7.
I3 CHECK THE ABS MODULE LATERAL ACCELERATION (LAT_ACCL) PID
- NOTE: The vehicle must be on level ground and at a complete standstill. Any vehicle movement results in false values for this test.
Monitor the LAT_ACCL PID.
Is the LAT_ACCL PID value between -0.4 and 0.4?
Yes
GO to I4.
No
GO to I7.
I4 CHECK THE ABS MODULE LONGITUDINAL ACCELERATION (LONG_ACCL) PID
- NOTE: The vehicle must be on level ground and at a complete standstill. Any vehicle movement results in false values for this test.
Monitor the LONG_ACCL PID.
Is the LONG_ACCL PID value between -0.4 and 0.4?
Yes
GO to I5.
No
GO to I7.
I5 CHECK THE ABS MODULE ROLL RATE (ROLLRAT) PID
NOTE: The vehicle must be on level ground and at a complete standstill. Any vehicle movement results in false values for this test.
- Monitor the ROLLRAT PID.
Is the ROLLRAT PID value between -0.05 and 0.05?
Yes
GO to I6.
No
GO to I7.
I6 CHECK THE STEERING WHEEL ANGLE SENSOR POSITION (SWA POS) PID
- Monitor the SWA POS PID while rotating the steering wheel clockwise and counterclockwise very slowly, from lock to lock.
Does the PID change in intervals of 4.5 degrees and show a 360-degree increase for each complete revolution of the steering wheel?
Yes
GO to I8.
No
GO to Pinpoint Test F. Pinpoint Test F: DTCs C1277, C1278 and C1963
I7 CHECK THE RCM (Restraints Control Module) INSTALLATION AND MOUNTING SURFACE
- Ignition OFF.
- Depower the Supplemental Restraint System (SRS). Refer to Restraints and Safety Systems &/or Air Bag Systems.
- After depowering the system, refer to Restraints Control Module (RCM) Removal and Installation in Restraints and Safety Systems &/or Air Bag Systems. Adhere to all safety warnings in the procedure while inspecting the RCM (Restraints Control Module) for damage or incorrect mounting.
- Inspect the RCM (Restraints Control Module) installation and make sure the nuts are fully seated and tightened correctly.
- Inspect the mounting surface for damage, corrosion or dirt.
Is the RCM (Restraints Control Module) installed correctly and is the mounting surface clean and free from damage?
Yes
REPLACE the RCM (Restraints Control Module) CLEAR the ABS module DTCs. TEST the system for normal
No
REINSTALL or REPAIR the RCM (Restraints Control Module) mounting surface or installation. CLEAR the ABS module DTCs. TEST the system for normal operation.
I8 CHECK FOR CORRECT ABS MODULE OPERATION
- Disconnect: ABS Module C135.
- Check the connector for:
- corrosion
- pushed-out pins
- spread terminals
- Connect: ABS Module C135.
- Make sure the ABS module electrical connector is fully seated, then operate the system and verify the concern is still present.
Is the concern still present?
Yes
INSTALL a new ABS module. REFER to Anti-Lock Brake System (ABS) Module . CLEAR the DTCs. REPEAT the self-test.
No
The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. CLEAR the DTCs. REPEAT the self-test.