Pinpoint Test M: DTCs C1277, C1278 and C1963
Anti-Lock Control - Traction Control and Stability Assist
Pinpoint Tests
Pinpoint Test M: DTCs C1277, C1278 and C1963
Refer to Wiring Diagrams Set 42, Vehicle Dynamic Systems for schematic and connector information. Diagrams By Number
Normal Operation
A toothed-wheel is attached to the steering column behind the clockspring and the steering wheel rotation sensor is attached to the RH side of the steering column just above the ignition lock cylinder. As the steering wheel is turned, the toothed-wheel passes through the magnetic field of the steering wheel rotation sensor indicating which direction and how fast the steering wheel is being turned. This information is sent to the ABS module and is used to help determine if the Electronic Stability Control (ESC) system needs to be activated.
The steering wheel position (in degrees) is sent to the ABS module along circuit VCS06 (GY/BN) and circuit VCS07 (VT/OG). Voltage is supplied to the sensor by the ABS module along circuit CCS01 (VT/WH) and ground is provided by the ABS module along circuit RCS02 (BU/WH).
- DTC C1277 (Steering Wheel Angle 1 and 2 Circuit Failure) - If during normal operation or the ABS module on-demand self test, the ABS module detects an open circuit, short to voltage or short to ground along circuits VCS06 (GY/BN) and VCS07 (VT/OG), DTC C1277 will be set. An internal failure of the steering wheel rotation sensor may also cause DTC C1277 to set.
- DTC C1278 (Steering Wheel Angle 1 and 2 Signal Faulted) - If during normal operation or the ABS module on-demand self test, the ABS module does not receive the steering wheel rotation sensor input or if the input received does not agree with the input from other sensors, DTC C1277 will be set.
- DTC C1963 (Stability Assist Inhibit Warning) - If conditions exist during normal operation that prevents the ESC system from operating, DTC C1963 will be set. This DTC is usually set due to the steering wheel rotation sensor or the stability control sensor cluster being damaged or installed incorrectly.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Steering wheel rotation sensor incorrectly installed
- Steering wheel rotation sensor
- ABS module
PINPOINT TEST M: DTCs C1277, C1278 AND C1963
NOTICE: Use the Flex Probe Kit for all test connections to prevent damage to the wiring terminals. Do not use standard multi-meter probes.
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M1 CHECK THE STEERING WHEEL ROTATION SENSOR CONDITION AND INSTALLATION
- Inspect the steering wheel rotation sensor and toothed-wheel for damage and correct installation. Refer to Steering Wheel Rotation Sensor Service and Repair.
- Are the sensor and toothed-wheel installed correctly and undamaged?
Yes
GO to M2.
No
REINSTALL or INSTALL new as necessary. CARRY OUT the IVD Initialization sequence, FOLLOW the scan tool directions. TEST the system for normal operation.
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M2 MONITOR THE STEERING POSITION SENSOR (SWA POS) PID
- Connect the scan tool.
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: DataLogger - ABS Module .
- Monitor the SWA POS PID while rotating the steering wheel clockwise and counterclockwise very slowly, from lock to lock.
- Do the PIDs change in intervals of 1.5 degrees and show a 360 degree increase for each complete revolution of the steering wheel?
Yes
GO to M3.
No
GO to M4.
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M3 CHECK FOR RETURNING DTCs
- Clear the ABS module DTCs.
- Drive the vehicle above 48 km/h (30 mph) with input from the steering wheel.
- Enter the following diagnostic mode on the scan tool: Self Test - ABS Module.
- Retrieve and record any ABS module DTCs.
- Are any ABS module DTCs present?
Yes
If DTC C1963, C1277 or C1278 is present, GO to M4.
For all other DTCs, GO to the ABS Module DTC Chart. ABS Module DTC Chart
No
The condition is not present at this time. INSPECT the rotation sensor and the toothed-wheel for cracks, looseness and foreign material. REPAIR or INSTALL new as necessary. TEST the system for normal operation.
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M4 CHECK THE VOLTAGE TO THE STEERING WHEEL ROTATION SENSOR
- Ignition OFF.
- Disconnect: Steering Wheel Rotation Sensor C226.
- Ignition ON.
- Measure the voltage between steering wheel rotation sensor C226-4, circuit CCS01 (VT/WH), harness side and ground.
- Is the voltage greater than 9.5 volts?
Yes
GO to M5.
No
REPAIR circuit CCS01 (VT/WH). CLEAR the DTCs. CARRY OUT the IVD Initialization sequence, FOLLOW the scan tool directions. REPEAT the self-test.
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M5 CHECK SENSOR GROUND CIRCUIT FOR AN OPEN
- Measure the voltage between steering wheel rotation sensor C226-4, circuit CCS01 (VT/WH) harness side and steering wheel rotation sensor C226-1, circuit RSC02 (BU/WH), harness side.
- Is the voltage greater than 9.5 volts?
Yes
GO to M6.
No
REPAIR circuit RSC02 (BU/WH). CLEAR the DTCs. CARRY OUT the IVD Initialization sequence, FOLLOW the scan tool directions. REPEAT the self-test.
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M6 CHECK ANGLE SENSOR 1 CIRCUIT FOR AN OPEN
- Measure the voltage between steering wheel rotation sensor C226-2, circuit VCS06 (GY/BN), harness side and steering wheel rotation sensor C226-1, circuit RCS02 (BU/WH), harness side.
- Is the voltage between 4.75 volts and 5.25 volts?
Yes
GO to M7.
No
REPAIR circuit VCS06 (GY/BN). CLEAR the DTCs. CARRY OUT the IVD Initialization sequence, FOLLOW the scan tool directions. REPEAT the self-test.
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M7 CHECK ANGLE SENSOR 2 CIRCUIT FOR AN OPEN OR SHORT TO GROUND
- Measure the voltage between steering wheel rotation sensor C226-3, circuit VCS07 (VT/OG), harness side and steering wheel rotation sensor C226-1, circuit RCS02 (BU/WH), harness side.
- Is the voltage between 4.75 volts and 5.25 volts?
Yes
GO to M8.
No
REPAIR circuit VCS07 (VT/OG). CLEAR the DTCs. CARRY OUT the IVD Initialization sequence, FOLLOW the scan tool directions. REPEAT the self-test.
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M8 CHECK THE STEERING POSITION SENSOR CIRCUITS FOR AN OPEN
- Ignition OFF.
- Disconnect: ABS Module C155.
- Disconnect: Steering Wheel Rotation Sensor C226.
- Measure the resistance between ABS module C155, harness side and steering wheel rotation sensor C226, harness side using the following table:
- Are the resistances less than 5 ohms?
Yes
GO to M9.
No
REPAIR the affected circuit(s). CLEAR the DTCs. CARRY OUT the IVD Initialization sequence, FOLLOW the scan tool directions. REPEAT the self-test.
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M9 CHECK THE STEERING POSITION SENSOR CIRCUITS FOR A SHORT TO VOLTAGE
- Ignition ON.
- Measure the voltage between:
- ABS module C155-5, circuit CCS01 (VT/WH), harness side and ground.
- ABS module C155-9, circuit VCS07 (VT/OG), harness side and ground.
- ABS module C155-40, circuit RCS02 (BU/WH), harness side and ground.
- ABS module C155-41, circuit VCS06 (GY/BN), harness side and ground.
- Is any voltage present?
Yes
REPAIR the affected circuit(s). CLEAR the DTCs. CARRY OUT the IVD Initialization sequence, FOLLOW the scan tool directions. REPEAT the self-test.
No
GO to M10.
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M10 CHECK THE STEERING POSITION SENSOR CIRCUITS FOR A SHORT TO GROUND
- Ignition OFF.
- Measure the resistance between:
- ABS module C155-5, circuit CCS01 (VT/WH), harness side and ground.
- ABS module C155-9, circuit VCS07 (VT/OG), harness side and ground.
- ABS module C155-40, circuit RCS02 (BU/WH), harness side and ground.
- ABS module C155-41, circuit VCS06 (GY/BN), harness side and ground.
- Are the resistances greater than 10,000 ohms?
Yes
If sent here because DTC C1963 is present, Go To Pinpoint Test N. Pinpoint Test N: DTCs B2741, C1279, C1280, C1281, C1282, C2777, C2778 and U1901
For all other concerns, INSTALL a new steering wheel rotation sensor. REFER to Steering Wheel Rotation Sensor Service and Repair. CLEAR the DTCs. REPEAT the self-test.
No
REPAIR the affected circuit(s). CLEAR the DTCs. CARRY OUT the IVD Initialization sequence, FOLLOW the scan tool directions. REPEAT the self-test.
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