Test H: DTCS C1278 and C1956 - Steering Angle Sensor Circuit Fault

Pinpoint Test H: DTCs C1278 and C1956 - Steering Angle Sensor Circuit Fault
Refer to Vehicle Dynamic Systems for schematic and connector information.

Normal Operation
The steering wheel rotation sensor monitors the steering wheel position when the slotted-wheel in the sensor passes through the optical field of the sensor.

Fused ignition voltage is supplied to the rotation sensor from battery junction box (BJB) fuse 38 (10A) along circuit CBB38 (GY/BU). Ground for the sensor is provided by the ABS module along circuit RCA09 (GN/VT). The steering wheel rotation sensor sends information to the ABS module along circuits VCS06 (GY/BN) and VCS07 (VT/OG). If the ground or power to the steering wheel rotation sensor is interrupted, DTC C1278 will be set.
^ DTC C1278 Steering Wheel Angle 1 and 2 Signal Faulted - If the ABS module receives a message from the sensor cluster that is out of the normal operating range or one that does not agree with other sensor information, DTC C1278 will be set.
^ DTC C1956 Steering Angle Sensor Circuit Failure
- If the ABS module detects an open, a short to ground or a short to voltage on any of the rotation sensor circuits, DTC C1956 will be set.

This pinpoint test is intended to diagnose the following:
^ Wiring, terminals or connectors
^ Steering wheel rotation sensor

H1-H4:

H4-H6:

H6-H7:

H8: