B3104

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PINPOINT TEST 2: DTC B2277, B2278, B3104, C1277 AND C1278 - ELECTRIC POWER STEERING MOTOR MALFUNCTION, STEERING SHAFT TORQUE SENSOR MALFUNCTION, STEERING SHAFT POSITION SENSOR MALFUNCTION, STEERING WHEEL ANGLE 1 AND 2 CIRCUIT FAILURE AND STEERING WHEEL ANGLE 1 AND 2 SIGNAL FAULTED

Normal Operation

The voltage required for correct electronic power assist steering (EPAS) system operation is 10-16 volts. Above or below that voltage range, DTC B1317 (battery voltage high) or DTC B1318 (battery voltage low) will be set. The EPAS motor, torque sensor and steering shaft/wheel position sensor are all integrated into the power steering control module. The power steering control module is integrated into the steering column. If any new components need to be installed, a new steering column must be installed.Fused ignition voltage for the EPAS system is supplied to the control module by smart junction box (SJB) fuse 35 (10A) along circuit (Y/GY). Fused battery voltage for the EPAS system motor is supplied to the power steering control module by battery junction box (BJB) fuse 1 (80A) along circuit (R). Ground for the power steering control module is provided along circuit (B/V). The power steering control module communicates with the other vehicle control modules along the high speed communication area network (HS-CAN) bus, circuits (W/L) and (W).

- DTC B2277 (Electric Power Steering Motor Malfunction) - an open or short in the power steering control module power or HS-CAN circuits, or an internal failure of the torque sensor itself will cause DTC B2277 to be set.
- DTC B2278 (Steering Shaft Torque Sensor Malfunction) - an open or short in the power steering control module power or HS-CAN circuits, or an internal failure of the torque sensor itself will cause DTC B2278 to be set.
- DTC B3104 (Steering Shaft Position Sensor Malfunction) - an open or short in the power steering control module power or HS-CAN circuits, or an internal failure of the shaft/wheel position sensor itself will cause DTC B3104 to be set.
- DTC C1277 (Steering Wheel Angle 1 and 2 Circuit Failure) - an open or short in the power steering control module power or HS-CAN circuits, or an internal failure of the shaft/wheel position sensor itself will cause DTC C1277 to be set.
- DTC C1278 (Steering Wheel Angle 1 and 2 Signal Faulted) - an open or short in the power steering control module power or HS-CAN circuits, or an internal failure of the shaft/wheel position sensor itself will cause DTC C1278 to be set.

Possible Causes
- Wiring, terminals or connectors
- Power steering control module

Diagnostic Procedure

CAUTION: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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