Pinpoint Test P: DTC C1996
Anti-Lock Control - Traction Control and Stability Assist
Pinpoint Tests
Pinpoint Test P: DTC C1996
Normal Operation
The ABS module uses information received from several sensors (wheel speed sensors, steering wheel rotation sensor, stability control sensor cluster, etc.) to determine if a vehicle instability event is about to occur. If an event is going to occur, the ABS module will adjust brake torque at specific wheels and the PCM will reduce engine torque to make the vehicle more stable. Once the ABS module has determined that the stability event has been corrected, it will return brake and engine torque to normal and continue 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 cluster
- Wheel speed sensors
- ABS module
PINPOINT TEST P: DTC C1996
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P1 CHECK THE WHEEL SPEED SENSOR PIDS
- Connect the scan tool.
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: DataLogger - ABS.
- While driving the vehicle, have an assistant monitor the following wheel speed sensor PIDs:
- Left Front Wheel Speed (LF_WSPD)
- Right Front Wheel Speed (RF_WSPD)
- Left Rear Wheel Speed (LR_WSPD)
- Right Rear Wheel Speed (RR_WSPD)
- Do all the PIDs match the vehicle speed and match each other?
Yes
GO to P6.
No
GO to P2.
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P2 INSPECT THE WHEEL SPEED SENSOR MOUNTING
- Ignition OFF.
- With the vehicle in NEUTRAL, position it on a hoist. Refer to Maintenance/Service and Repair.
- Verify the bolt of the suspect wheel speed sensor is tightened to specifications.
- Is the bolt tightened to specifications?
Yes
GO to P3.
No
TIGHTEN the wheel speed sensor bolt to specification. REFER to Specifications. CLEAR the DTCs.
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P3 INSPECT THE WHEEL SPEED SENSOR AND HARNESS FOR DAMAGE
- NOTE: Examine the wheel speed sensor harness carefully with a good light source. Failure to verify damage in the sensor harness can lead to unnecessary installation of a new component.
- Inspect the suspect wheel speed sensor and harness for cuts, broken tabs, broken casing and/or corrosion.
- Are the wheel speed sensor and harness OK?
Yes
GO to P4.
No
INSTALL a new wheel speed sensor. REFER to Wheel Speed Sensor - Front Wheel Speed Sensor - Front or Wheel Speed Sensor - Rear Wheel Speed Sensor - Rear. CLEAR the DTCs. REPEAT the self-test.
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P4 INSPECT THE WHEEL SPEED SENSOR RING FOR DAMAGE
- NOTE: Examine the wheel speed sensor ring carefully with a good light source. Failure to verify damage in the sensor ring can lead to unnecessary installation of a new component.
- Inspect the suspect wheel speed sensor ring for cracks, chips or missing teeth. Rotate the wheel to verify that no teeth are missing.
- Is the wheel speed sensor ring OK?
Yes
GO to P5.
No
INSTALL a new wheel hub and bearing assembly (wheel speed sensor rings are part of the wheel hub and bearing assembly). CLEAR the DTCs. REPEAT the self-test.
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P5 INSPECT THE WHEEL BEARING FOR DAMAGE AND LOOSENESS
- Verify that the wheel bearing has no end-play and is undamaged.
- Is the wheel bearing OK?
Yes
GO to P6.
No
INSTALL a new wheel hub and bearing assembly. CLEAR the DTCs. REPEAT the self-test.
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P6 CHECK THE ABS MODULE YAW RATE (YAWRATE) 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 YAWRATE PID.
- Is the YAWRATE PID value between -0.004 and 0.004?
Yes
GO to P7.
No
GO to P8.
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P7 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 -0.3 and 0.3?
Yes
GO to P9.
No
GO to P8.
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P8 CHECK THE SENSOR CLUSTER INSTALLATION AND MOUNTING SURFACE
- Inspect the sensor cluster installation and make sure that the nuts are fully seated and tightened correctly. Refer to Stability Control Sensor Cluster Service and Repair.
- Inspect the mounting surface for damage, corrosion or dirt.
- Were the sensor cluster installed incorrectly and is the mounting surface clean and free from damage?
Yes
GO to P9.
No
REPAIR or INSTALL new as necessary. CLEAR the DTC. REPEAT the self-test.
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P9 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 1.5 degrees and show a 360-degree increase for each complete revolution of the steering wheel?
Yes
GO to P10.
No
Go To Pinpoint Test M. Pinpoint Test M: DTCs C1277, C1278 and C1963
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P10 CHECK FOR CORRECT ABS MODULE OPERATION
- Disconnect: ABS Module C155.
- Check the connector for:
- corrosion.
- pushed-out pins.
- spread terminals.
- Connect: ABS Module C155.
- 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 Service and Repair. 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.
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