Pinpoint Test N: DTC C1963
Anti-Lock Control - Traction Control and Stability Assist
Pinpoint Test N: DTC C1963
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 vehicle stability, traction or roll warrants Electronic Stability Control (ESC) or Roll Stability Control (RSC(R)) interaction. If interaction is warranted, 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 continue to monitor the vehicle.
If conditions exist during normal operation that prevents the ESC (Electronic Stability Control) or the RSC(R) (Roll Stability Control) system from operating, DTC C1963 sets. This DTC is usually set due to the steering wheel rotation sensor or the Restraints Control Module (RCM) being damaged or installed incorrectly. This DTC cannot clear until the vehicle has been driven above 48 km/h (30 mph) with input from the steering wheel rotation sensor.
- DTC C1963 (Stability Control Inhibit Warning)- Once every key-cycle the ABS module determines the straight-ahead or center position of the steering wheel by monitoring the steering wheel rotation sensor while the vehicle is being driven. If the vehicle reaches a speed of 75 km/h (47 mph) without finding the center position or if 30 seconds has passed since the initial drive-off without finding the center position, DTC C1963 sets.
This pinpoint test is intended to diagnose the following:
- Steering wheel rotation sensor
- Stability control sensors
- Wheel speed sensors
- ABS module
PINPOINT TEST N : DTC C1963
N1 CHECK FOR ABS MODULE DTCs
- Review the DTCs retrieved during Inspection and Verification.
Are any ABS module DTCs other than C1963 present?
Yes
REPAIR all other DTCs before repairing C1963. GO to the ABS Module DTC Chart. Anti-Lock Control
No
GO to N2.
N2 CHECK RETURNING DTCs
- Connect the scan tool.
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: Self Test- Clear All CMDTCs (Continuous Memory Diagnostic Trouble Codes).
- Cycle the ignition switch from RUN to OFF and back to RUN.
- Test drive the vehicle above 75 km/h (47 mph).
- Enter the following diagnostic mode on the scan tool: Self Test- ABS Module.
Are any ABS module DTCs present?
Yes
If only C1963 is present, GO to N3.
If DTC C1963 is present along with other DTCs, REPAIR the other DTCs before repairing DTC C1963. GO to the ABS Module DTC Chart. Anti-Lock Control
No
The condition is not present at this time. INSPECT the rotation sensor and the slotted-wheel for cracks, looseness and foreign material. REPAIR or INSTALL new as necessary. Using the scan tool, CARRY OUT the IVD Initialization sequence. CLEAR the DTCs. REPEAT the self-test.
N3 CHECK THE WHEEL SPEED SENSOR PIDS
- Enter the following diagnostic mode on the scan tool: DataLogger- ABS Module.
- While driving the vehicle, have an assistant monitor the following wheel speed sensor PIDs:
- Left Front Wheel Speed Sensor (LF_WSPD)
- Right Front Wheel Speed Sensor (RF_WSPD)
- Left Rear Wheel Speed Sensor (LR_WSPD)
- Right Rear Wheel Speed Sensor (RR_WSPD)
Do all the PIDs match the vehicle speed and match each other?
Yes
GO to N7.
No
GO to N4.
N4 INSPECT THE WHEEL SPEED SENSOR MOUNTING
- Ignition OFF.
- With the vehicle in NEUTRAL, position it on a hoist.
- Verify the bolt of the suspect wheel speed sensor is tightened to specifications.
Is the bolt tightened to specifications?
Yes
GO to N5.
No
TIGHTEN the wheel speed sensor bolt to specification. REFER to Specifications. CLEAR the DTCs. REPEAT the self-test.
N5 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 or corrosion.
Are the wheel speed sensor and harness OK?
Yes
GO to N6.
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.
N6 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 N7.
No
INSTALL a new wheel speed sensor ring. For front wheel speed sensor rings, REFER to Wheel Speed Sensor Ring - Front Wheel Speed Sensor Ring - Front. For rear wheel speed sensor rings, REFER to Axle Shaft in Differential Assembly &/or Axle Shaft Assembly. CLEAR the DTCs. REPEAT the self-test.
N7 CHECK THE ABS MODULE YAW RATE (YAW_RATE) 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 YAW_RATE PID.
Is the YAW_RATE PID value between -0.05 and 0.05?
Yes
GO to N8.
No
GO to N11.
N8 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 -0.007 and 0.007?
Yes
GO to N9.
No
GO to N11.
N9 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 -0.004 and 0.004?
Yes
GO to N10.
No
GO to N11.
N10 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 ROLL_RAT PID value between -0.05 and 0.05?
Yes
GO to N12.
No
GO to N11.
N11 CHECK THE RCM (Restraints Control Module) INSTALLATION AND MOUNTING SURFACE
- Ignition OFF.
- Depower the Supplemental Restraint System (SRS). Refer to Supplemental Restraint System (SRS) Depowering and Repowering in Restraints and Safety Systems &/or Air Bag Systems.
- Inspect the RCM (Restraints Control Module) installation and make sure that the nuts are fully seated and tightened correctly.
- Inspect the mounting surface for damage, corrosion or debris.
Is the RCM (Restraints Control Module) installed correctly and is the mounting surface clean and free from damage?
Yes
GO to N15.
No
REPAIR or INSTALL new as necessary. CLEAR the DTC. Using the scan tool, CARRY OUT the IVD Initialization sequence. CLEAR the DTCs. REPEAT the self-test.
N12 CHECK THE STEERING WHEEL ROTATION 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 N14.
No
GO to N13.
N13 INSPECT THE STEERING WHEEL ROTATION SENSOR
- Inspect the steering wheel rotation sensor and tone ring installation and make sure that fasteners are fully seated and tightened correctly. Refer to Steering Wheel Rotation Sensor Service and Repair.
- Inspect the steering wheel rotation sensor tone ring for damage or debris.
Is the steering wheel rotation sensor and tone ring installed incorrectly, clean and free from damage?
Yes
GO to N14.
No
REPAIR, CLEAN or INSTALL new as necessary. Using the scan tool, CARRY OUT the IVD Initialization sequence. CLEAR the DTC. REPEAT the self-test.
N14 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. Using the scan tool, CARRY OUT the IVD Initialization sequence. CARRY OUT the self-test with the brake pedal not applied.
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.
N15 CHECK FOR ADDITIONAL ABS MODULE DTCs
- WARNING: Turn the ignition OFF and wait one minute to deplete the backup power supply. Failure to follow this instruction may result in serious personal injury or death in the event of an accidental deployment.
- Reconnect all SRS (Supplemental Restraint System) components (if previously disconnected).
- If previously directed to depower the SRS (Supplemental Restraint System), repower the SRS (Supplemental Restraint System). Do not prove out the SRS (Supplemental Restraint System) at this time. Refer to Supplemental Restraint System (SRS) Depowering and Repowering in Restraints and Safety Systems &/or Air Bag Systems.
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: Self Test- Clear All CMDTCs (Continuous Memory Diagnostic Trouble Codes).
- Enter the following diagnostic mode on the scan tool: Self Test- ABS Module.
Is DTC C1963 present?
Yes
INSTALL a new RCM (Restraints Control Module). Using the scan tool, CARRY OUT the IVD Initialization sequence. 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.