Pinpoint Test G: DTC C1277/C1278 - STEERING WHEEL ANGLE 1 AND 2 CIRCUIT FAILURE/FAULTED
WARNING: This page is about a different car, the 2005 Lincoln LS. However, it is still accessible from the selected car via links, so may be relevant.
CAUTION:
Use the Flex Probe Kit for all test connections to prevent damage to the wiring terminals. Do not use standard multimeter probes.
- G1 CARRY OUT THE RECALIBRATION PROCEDURE FOR THE STEERING WHEEL ROTATION SENSOR
- Key in ON position.
- Enter the following diagnostic mode on the diagnostic tool: Clear the DTC.
- Carry out the steering wheel rotation sensor recalibration procedure using the diagnostic tool.
- Follow the diagnostic tool directions for the calibration procedure. REFER to MODULE CONFIGURATION .
- Enter the following diagnostic mode on the diagnostic tool: Retrieve DTCs.
- Are any DTCs retrieved or does the recalibration procedure indicate a fault?
- Yes
: If DTC C1277 or C1278 is retrieved or the recalibration procedure indicates a fault, GO to G2.
If any other DTC is retrieved, GO to the ABS (WITH OR WITHOUT ADVANCE TRAC®/IVD) MODULE DIAGNOSTIC TROUBLE CODE (DTC) INDEX .
- No : The ABS system is operating correctly.
The DTC C1278 was meant for detection of steering wheel rotation sensor harness wiring problems at vehicle assembly time. The steering wheel rotation sensor circuit is checked for swapped wires (channel A and B). This DTC should not occur during repair unless the harness wiring to the steering wheel rotation sensor was changed or the PRNDL position indicator is not operating correctly. The DTC will occur only after driving a few feet and making a turn if the wiring problem or PRNDL problem exists.
- G2 MONITOR THE STEERING ROTATION SENSOR PIDs
- Key in ON position.
- Monitor the steering rotation sensor PIDs while rotating the steering wheel clockwise and counterclockwise.
- Are the 2 PID values similar?
- Yes
: CLEAR the DTC. DRIVE the vehicle.
RETRIEVE the DTCs. If DTC C1277 is present, INSTALL a new ABS control module. RECALIBRATE the ABS module. FOLLOW the diagnostic tool directions for the calibration procedure. REFER to MODULE CONFIGURATION . REPEAT the self-test.
- No : GO to G3.
- G3 CHECK THE VOLTAGE TO THE STEERING WHEEL ROTATION SENSOR
- Key in OFF position.
- Disconnect: Steering Wheel Rotation Sensor C226.
- Key in ON position.
- Measure the voltage between steering wheel rotation sensor C226-1, circuit 7-CC16A (YE/BK), harness side and ground.
- Is the voltage greater than 5 volts?
- Yes : GO to G4.
- No : REPAIR the circuit in question. CLEAR the DTC. RECALIBRATE the ABS module. FOLLOW the diagnostic tool directions for the calibration procedure. REFER to MODULE CONFIGURATION . REPEAT the self-test.
- G4 CHECK THE STEERING WHEEL ROTATION SENSOR CIRCUITRY FOR AN OPEN
- Key in OFF position.
- Disconnect: ABS Module C155.
- Measure the resistance between ABS module C155 pins, harness side and steering wheel rotation sensor C226 pins, harness side as follows:
Steering Wheel Rotation Sensor C226 Pin Circuit ABS Module C155 Pin Circuit 2 10-CC17 (GY) 6 10-CC17 (GY) 3 8-CC18 (WH/RD) 3 8-CC18 (WH/RD) 4 9-CC1 (BN/YE) 5 9-CC1 (BN/RD) - Are the resistances less than 5 ohms?
- Yes : GO to G5.
- No : REPAIR the circuit in question. CLEAR the DTC. RECALIBRATE the ABS module. FOLLOW the diagnostic tool directions for the calibration procedure. REFER to MODULE CONFIGURATION . REPEAT the self-test.
- G5 CHECK THE STEERING WHEEL ROTATION SENSOR FOR A SHORT TO VOLTAGE
- Key in OFF position.
- Connect: Steering Wheel Rotation Sensor C226.
- Disconnect: ABS Module C155.
- Key in ON position.
- Measure the voltage between ABS module C155 pins, harness side and ground as follows:
ABS Module C155 Pin Circuit 6 10-CC17 (GY) 3 8-CC18 (WH/RD) 5 9-CC1 (BN/RD) - Is any voltage present?
- Yes : REPAIR the circuit in question. CLEAR the DTC. RECALIBRATE the ABS module. FOLLOW the diagnostic tool directions for the calibration procedure. REFER to MODULE CONFIGURATION . REPEAT the self-test.
- No : GO to G6.
- G6 CHECK THE STEERING WHEEL ROTATION SENSOR CIRCUITRY FOR A SHORT TO GROUND
- Key in OFF position.
- Measure the resistance between ABS module C155 pins, harness side and ground as follows:
ABS Module C155 Pin Circuit 6 10-CC17 (GY) 3 8-CC18 (WH/RD) 5 9-CC1 (BN/RD) - Is the resistance greater than 10,000 ohms?
- Yes : INSTALL a new steering rotation sensor. REFER to STEERING WHEEL ROTATION SENSOR in this article . CLEAR the DTC. REPEAT the self-test.
- No : REPAIR the circuit in question. CLEAR the DTC. RECALIBRATE the ABS module. FOLLOW the diagnostic tool directions for the calibration procedure. REFER to MODULE CONFIGURATION . REPEAT the self-test.