Pinpoint Test G: DTC C1277 And C1278 - Steering Wheel Angle 1 And 2 Circuit Failure/Faulted

WARNING: This page is about a different car, the 2005 Mercury Mountaineer and 2005 Ford Explorer. However, it is still accessible from the selected car via links, so may be relevant.

CAUTION: Use the flex probe kit for all test connections to prevent damage to the wiring terminals. Do not use standard multimeter probes.

G1 CARRY OUT THE RECALIBRATION PROCEDURE
- Key in ON position.
- Enter the following diagnostic mode on the diagnostic tool: Clear the DTCs.
- Carry out the steering position sensor recalibration procedure following the diagnostic tool directions.
- Enter the following diagnostic mode on the diagnostic tool: Retrieve DTCs.
- Are any DTCs retrieved or does the recalibration procedure indicate a fault?
- Yes : If DTC C1277 or C1278 is retrieved, or the recalibration procedure indicates a fault, GO to G2.
  If any other DTCs are retrieved, GO to the ANTI-LOCK BRAKE SYSTEM (ABS) MODULE DIAGNOSTIC TROUBLE CODE (DTC) INDEX . If sent here from Pinpoint Test Q, GO to G2.
- No : The ABS system is operating correctly.
G2 MONITOR THE STEERING POSITION SENSOR PIDs
- Make sure the steering wheel is centered straight forward.
- Enter the following diagnostic mode on the diagnostic tool: ABS Module PIDs.
- Monitor the ABS module steering position sensor PID while rotating the steering wheel clockwise and counterclockwise.
- Are the 2 PID values similar?
- Yes : CLEAR the DTCs. DRIVE the vehicle. RETRIEVE the DTCs. If DTC C1277 is present, INSTALL a new ABS module. REFER to ANTI-LOCK BRAKE SYSTEM (ABS) MODULE . CALIBRATE the ABS module. FOLLOW the diagnostic tool directions for the calibration procedure.
- No : If the value is less than 360, GO to G3.
  If the value is greater than 360, REFER to SUSPENSION SYSTEM-GENERAL INFORMATION for alignment concerns, FRONT SUSPENSION - 4X2 or FRONT SUSPENSION - 4X4 for suspension concerns, or STEERING COLUMN for steering column concerns. CLEAR the DTCs. REPEAT the self-test.
G3 CHECK CIRCUIT 1003 (GY/YE) FOR AN OPEN
- Key in OFF position.
- Disconnect: Steering Position Sensor C226.
- Key in ON position.
- Measure the voltage between the steering position sensor C266-1, circuit 1003 (GY/YE), harness side and ground.
  
  Fig 1: Checking Circuit 1003 (GY/YE) For Open
  Courtesy of FORD MOTOR CO.
- Is the voltage greater than 10 volts?
- Yes : GO to G4.
- No : REPAIR the circuit. CLEAR the DTCs. CALIBRATE the ABS module. FOLLOW the diagnostic tool directions for the calibration procedure. REPEAT the self-test.

G4 CHECK THE STEERING POSITION SENSOR CIRCUITRY FOR AN OPEN

Key in OFF position.
Disconnect: ABS Module C155.

Measure the resistance between the ABS module connector, harness side and the steering position sensor connector, harness side as follows:

STEERING POSITION SENSOR AND ABS MODULE CONNECTOR AND CIRCUIT

Steering Position Sensor Connector-Pin	ABS Module Connector-Pin	Circuit
C226-2	C155-6	1573 (YE)
C226-3	C155-3	1572 (DG)
C226-4	C155-5	1571 (B/K)1577 (RD/LB)

Fig 2: Checking Steering Position Sensor Circuitry For An Open

Courtesy of FORD MOTOR CO.

Are the resistances less than 5 ohms?

Yes : GO to G5.
No : REPAIR the circuit(s) in question. CLEAR the DTCs. CALIBRATE the ABS module. FOLLOW the diagnostic tool directions for the calibration procedure. REPEAT the self-test.

G5 CHECK THE STEERING POSITION SENSOR CIRCUITS FOR A SHORT TO VOLTAGE

Key in ON position.

Measure the voltage between the ABS module connector, harness side and ground as follows:

ABS MODULE CONNECTOR AND CIRCUIT

ABS Module Connector-Pin	Circuit
C155-6	1573 (YE)
C155-3	1572 (DG)
C155-5	1577 (RD/LB)

Fig 3: Checking Steering Position Sensor Circuits For Short To Voltage

Courtesy of FORD MOTOR CO.

Is any voltage present?

Yes : REPAIR the circuit(s) in question. CLEAR the DTCs. CALIBRATE the ABS module. FOLLOW the diagnostic tool directions for the calibration procedure. REPEAT the self-test.
No : GO to G6.

G6 CHECK THE STEERING POSITION SENSOR CIRCUITRY FOR A SHORT TO GROUND

Key in OFF position.

Measure the resistance between the ABS module connector, harness side and ground as follows:

ABS MODULE CONNECTOR AND CIRCUIT

ABS Module Connector-Pin	Circuit
C155-6	1573 (YE)
C155-3	1572 (DG)
C155-5	1577 (RD/LB)

Fig 4: Checking Steering Position Sensor Circuitry For Short To Ground

Courtesy of FORD MOTOR CO.

Are the resistances greater than 10,000 ohms?

Yes : INSTALL a new clockspring. REFER to SUPPLEMENTAL RESTRAINT SYSTEM . CLEAR the DTCs. REPEAT the self-test.
No : REPAIR the circuit in question. CLEAR the DTCs. CALIBRATE the ABS module. FOLLOW the diagnostic tool directions for the calibration procedure. REPEAT the self-test.