PINPOINT TEST F: DTCs C1277, C1278 AND C1963
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.
NOTE:
Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.
- F1 VERIFY THE VEHICLE STEERING SYSTEM TYPE
- Verify the type of steering system the vehicle is equipped with, HPAS or EPAS.
- Is the vehicle equipped with HPAS?
NOTE: Steering system type can be identified by checking for the presence of a power steering pump. Vehicles equipped with EPAS do not have a power steering pump.- Yes : GO to F4.
- No : GO to F2.
- F2 CHECK THE ABS MODULE DTCs
- Review the DTCs retrieved during Inspection and Verification.
- Are there any communication "U-code" DTCs present in the ABS module?
- Yes : REFER to the ABS MODULE DTC TABLE and DIAGNOSE the U-code DTCs before diagnosing DTC C1963.
- No : GO to F3.
- F3 CHECK FOR PSCM DTCs
- Connect the scan tool.
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: Self Test - PSCM.
- Are there any DTCs present in the PSCM?
- Yes : REFER to STEERING SYSTEM - ELECTRONIC POWER ASSIST STEERING (EPAS) article to diagnose the EPAS system concern.
- No : GO to PINPOINT TEST G .
- F4 MONITOR THE STEERING ROTATION SENSOR POSITION (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.
- Does the PID move in intervals of 1.5 degrees?
- Yes
: CLEAR the DTCs. DRIVE the vehicle above 48 km/h (30 mph) with input from the steering wheel rotation sensor. RETRIEVE the DTCs. If DTC C1277 or C1278 is still present, GO to F13.
If DTC C1963 is present, INSPECT the steering wheel rotation sensor for damage and correct installation. INSPECT for possible sources of light intrusion (cracked, missing or poor fitting steering shroud). REINSTALL or INSTALL new as necessary. If the sensor is OK, GO to F5.
- No : GO to F5.
- F5 CHECK THE VOLTAGE TO THE STEERING WHEEL ROTATION SENSOR NOTE: The steering wheel rotation sensor is located on the RH side of the multifunction switch.
- Ignition OFF.
- Disconnect: Steering Wheel Rotation Sensor C226.
- Ignition ON.
- Measure the voltage between steering wheel rotation sensor C226-4, circuit CCA40 (GY/BU), harness side and ground.
- Is the voltage greater than 9.5 volts?
- Yes : GO to F6.
- No : REPAIR circuit CCA40 (GY/BU). CLEAR the DTCs. REPEAT the self-test.
- F6 CHECK THE GROUND CIRCUIT FOR AN OPEN
- Measure the voltage between steering wheel rotation sensor C226-4, circuit CCA40 (GY/BU), harness side and steering wheel rotation sensor C226-1, circuit RCA40 (BN/VT), harness side.
- Is the voltage greater than 9.5 volts?
- Yes : GO to F7.
- No : REPAIR circuit RCA40 (BN/VT). CLEAR the DTCs. REPEAT the self-test.
- F7 CHECK THE CHANNEL "A" CIRCUIT FOR AN OPEN OR A SHORT TO GROUND
- Measure the voltage between steering wheel rotation sensor C226-2, circuit VCA41 (VT/GN), harness side and steering wheel rotation sensor C226-1, circuit RCA40 (BN/VT), harness side.
- Is the voltage between 4.75 volts and 5.25 volts?
- Yes : GO to F8.
- No : REPAIR circuit VCA41 (VT/GN). CLEAR the DTCs. REPEAT the self-test.
- F8 CHECK THE CHANNEL "B" CIRCUIT FOR AN OPEN OR A SHORT TO GROUND
- Measure the voltage between steering wheel rotation sensor C226-3, circuit VCA42 (VT/OG), harness side and steering wheel rotation sensor C226-1, circuit RCA40 (BN/VT), harness side.
- Is the voltage between 4.75 volts and 5.25 volts?
- Yes : GO to F9.
- No : REPAIR circuit VCA42 (VT/OG). CLEAR the DTCs. REPEAT the self-test.
- F9 CHECK THE STEERING POSITION SENSOR CIRCUITS FOR AN OPEN NOTE: The degas bottle may need to be positioned aside to access the ABS module connector.
- Ignition OFF.
- Disconnect: ABS Module C135.
- Disconnect: Steering Wheel Rotation Sensor C226.
- Measure the resistance between ABS module C135, harness side and steering wheel rotation sensor C226, harness side using the following table:STEERING WHEEL ROTATION SENSOR RESISTANCE TABLE
Steering Wheel Rotation Sensor Circuit ABS Module C226-1 RCA40 (BN/VT) C135-40 C226-2 VCA41 (VT/GN) C135-41 C226-3 VCA42 (VT/OG) C135-9 C226-4 CCA40 (GY/BU) C135-5 - Are the resistances less than 5 ohms?
- Yes : GO to F10.
- No : REPAIR the affected circuit(s). CLEAR the DTCs. REPEAT the self-test.
- F10 CHECK THE STEERING POSITION SENSOR CIRCUITS FOR A SHORT TO VOLTAGE
- Ignition ON.
- Measure the voltage between:
- ABS module C135-5, circuit CCA40 (GY/BU), harness side and ground.
- ABS module C135-9, circuit VCA42 (VT/OG), harness side and ground.
- ABS module C135-40, circuit RCA40 (BN/VT), harness side and ground.
- ABS module C135-41, circuit VCA41 (VT/GN), harness side and ground.
- Is any voltage present?
- Yes : REPAIR the affected circuit(s). CLEAR the DTCs. REPEAT the self-test.
- No : GO to F11.
- F11 CHECK THE STEERING POSITION SENSOR CIRCUITS FOR A SHORT TO GROUND
- Ignition OFF.
- Measure the resistance between:
- ABS module C135-5, circuit CCA40 (GY/BU), harness side and ground.
- ABS module C135-9, circuit VCA42 (VT/OG), harness side and ground.
- ABS module C135-40, circuit RCA40 (BN/VT), harness side and ground.
- ABS module C135-41, circuit VCA41 (VT/GN), harness side and ground.
- Are the resistances greater than 10,000 ohms?
- Yes : GO to F12.
- No : REPAIR the affected circuit(s). CLEAR the DTCs. REPEAT the self-test.
- F12 CHECK THE CHANNEL "A" AND "B" CIRCUITS FOR A SHORT TOGETHER
- Measure the resistance between steering wheel rotation sensor C226-2, circuit VCA41 (VT/GN), harness side and steering wheel rotation sensor C226-3, circuit VCA42 (VT/OG), harness side.
- Are the resistances greater than 10,000 ohms?
- Yes : If DTC C1963 is present, GO to PINPOINT TEST G . INSTALL a new steering wheel rotation sensor. REFER to STEERING WHEEL ROTATION SENSOR in this service information. CLEAR the DTCs. REPEAT the self-test.
- No : REPAIR the affected circuit(s). CLEAR the DTCs. REPEAT the self-test.
- F13 CHECK FOR CORRECT ABS MODULE OPERATION
- Ignition OFF.
- Disconnect: ABS Module C135.
- Check the connector for:
- corrosion.
- pushed-out pins.
- spread terminals.
- Connect: ABS Module C135.
- Make sure the connector seats correctly, then operate the system and verify the concern is still present.
- Is the concern still present?
- Yes : INSTALL a new ABS module. REFER to ANTI-LOCK BRAKE SYSTEM (ABS) MODULE in this service information. TEST the system for normal operation.
- No : The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. CLEAR the DTCs. REPEAT the self-test.