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Home >> Ford >> 2006 >> Focus ZX5 SE, Standard >> Repair and Diagnosis >> External Pages >> Different car >> Section 1540 (Anti-Lock Brake System - Vehicle Dynamic Systems) >> Diagnosis And Testing >> Anti-Lock Control - Non-Hybrid >> Pinpoint Tests >> Pinpoint Test F: DTCs C1277, C1278 and C1963 >> Normal Operation

Normal Operation

WARNING: This page is about a different car, the 2011 Mercury Milan, 2011 Lincoln MKZ, and 2011 Ford Fusion. However, it is still accessible from the selected car via links, so may be relevant.

On vehicles equipped with Hydraulic Power Assist Steering (HPAS) (3.5L vehicles only), a slotted wheel is attached to the steering column inside the clockspring and the steering wheel rotation sensor is attached to the RH side of the multifunction switch just above the ignition lock cylinder. The steering wheel rotation senor has a LED and an opposing optical sensor. As the steering wheel is turned, the slotted wheel passes between the LED and the sensor, interrupting the signal and indicating how far 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 AdvanceTrac® system needs to be activated.

On vehicles equipped with Electronic Power Assist Steering (EPAS), the steering wheel rotation sensor is located inside the EPAS gear assembly. Rotation speed and angle are sent to the ABS module from the Power Steering Control Module (PSCM) along the High Speed Controller Area Network (HS-CAN) bus.

DTC DESCRIPTION TABLE

DTC Description Fault Trigger Condition
  • C1277 - Steering Wheel Angle 1 and 2 Circuit Failure (vehicles with HPAS)
 If the ABS module detects an open circuit, short to voltage or short to ground during normal operation or an on-demand self test, DTC C1277 sets. An internal failure of the steering wheel rotation sensor may also cause DTC C1277 to set.
  • C1277 - Steering Wheel Angle 1 and 2 Circuit Failure (vehicles with EPAS)
 If the ABS module does not receive the steering wheel rotation/angle message from the PSCM for more than 5 seconds with vehicle speed above 3 km/h (2 mph), DTC C1277 sets. This could be due to a failure of the HS-CAN bus or a failure of the EPAS system, which causes other ABS module DTCs to set.
  • 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 C1278 sets.
  • C1963 - Stability Assist Inhibit Warning
 If conditions exist during normal operation that prevent the AdvanceTrac® system from operating, DTC C1963 sets. This DTC is usually set due to the steering wheel rotation sensor being damaged/installed incorrectly or due to invalid/missing data from the Restraints Control Module (RCM).

This pinpoint test is intended to diagnose the following: 

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