FREE REPAIR MANUALS & LABOR GUIDES 1982-2013 Vehicles
Courtesy of Operation CHARM: Car repair manuals for everyone.
Home >> Mercury >> 2009 >> Sable AWD V6-3.5L >> Repair and Diagnosis >> Brakes and Traction Control >> Antilock Brakes / Traction Control Systems >> Testing and Inspection >> Pinpoint Tests >> Pinpoint Test H: DTCs C1278, C1956, C1963 And C1975

Pinpoint Test H: DTCs C1278, C1956, C1963 And C1975




Anti-Lock Control

Pinpoint Tests

Pinpoint Test H: DTCs C1278, C1956, C1963 and C1975

Refer to Wiring Diagram Set 42, Vehicle Dynamic Systems for schematic and connector information. Diagrams By Number

Normal Operation

The steering wheel rotation sensor measures the rate of rotation of the steering wheel by monitoring a slotted-wheel as it passes through the sensor gap. This information is sent to the ABS module along 2 hard-wired circuits. The ABS module uses this information for Electronic Stability Control (ESC) system operation. The ABS module also compares this information to information it receives from other sensors (brake pedal input, stability control sensor cluster, etc.) to determine how valid the information is and to determine if an instability event is about to occur.

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-DTC C1975:





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



PINPOINT TEST H: DTCs C1278, C1956, C1963 AND C1975

NOTICE: Use the Flex Probe Kit for all test connections to prevent damage to the wiring terminals. Do not use standard multi-meter probes.

NOTICE: Overtightening of the steering wheel rotation sensor fasteners may deform or damage the sensor housing, possibly resulting in faulty operation.

NOTE: Make sure that the steering wheel rotation sensor is mounted securely to the column with 2 fasteners. A loose sensor or missing fastener may result in incorrect sensor operation. Make sure that the sensor connector is mated securely to the harness connector. Before proceeding with electrical testing, make sure that the vehicle battery is fully charged.

-------------------------------------------------
H1 MONITOR THE STEERING WHEEL ANGLE (SWA) PID


- Connect the scan tool.
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: DataLogger - ABS Module .
- Monitor the SWA PID while rotating the steering wheel clockwise and counterclockwise very slowly, from lock to lock.
- Do the PIDs change in 1.0 degree intervals and show a 360 degree increase for each complete revolution of the steering wheel?

Yes
GO to H2.

No
GO to H3.

-------------------------------------------------
H2 CHECK FOR RETURNING DTCs


- Clear the ABS module DTCs.
- Drive the vehicle above 48 km/h (30 mph) with input from the steering wheel.
- Enter the following diagnostic mode on the scan tool: Self Test - ABS Module.
- Retrieve and record any ABS module DTCs.
- Are any ABS module DTCs present?

Yes
If DTCs C1278, C1963 or C1975 are present, GO to H3.

For all other DTCs, GO to the ABS Module DTC Chart. ABS Module DTC Chart

No
The condition is not present at this time. INSPECT the rotation sensor and the slotted-wheel for cracks, looseness and foreign material. REPAIR or INSTALL new as necessary. CLEAR the DTCs. CYCLE the ignition key. REPEAT the self-test. If DTCs C1963 and/or C1975 return, Go To Pinpoint Test I. Pinpoint Test I: DTCs C1279, C1280, C1281, C1282, C1963, C1975, C2769, C2770 And U0074

-------------------------------------------------
H3 CHECK THE STEERING WHEEL ROTATION SENSOR CONDITION AND INSTALLATION


- Inspect the steering wheel rotation sensor and slotted-wheel for damage and correct installation. Refer to Steering Wheel Rotation Sensor Service and Repair.
- Are the sensor and toothed-wheel installed correctly and undamaged?

Yes
GO to H4.

No
REINSTALL or INSTALL new as necessary. CLEAR the DTCs. CYCLE the ignition key. REPEAT the self-test. If DTCs C1963 and/or C1975 return, Go To Pinpoint Test I. Pinpoint Test I: DTCs C1279, C1280, C1281, C1282, C1963, C1975, C2769, C2770 And U0074

-------------------------------------------------
H4 CHECK FOR VOLTAGE AT THE STEERING WHEEL ROTATION SENSOR


- Ignition OFF.
- Disconnect: Steering Wheel Rotation Sensor C226.
- Ignition ON.
- Measure the voltage between steering wheel rotation sensor C226-4, circuit CBB38 (GY/BU), harness side and ground.




- Is the voltage greater than 10 volts?

Yes
GO to H5.

No
VERIFY BJB fuse 38 (10A) is OK. If OK, REPAIR circuit CBB38 (GY/BU). CLEAR the DTCs. CYCLE the ignition key. REPEAT the self-test.

If not OK, Refer to the Wiring Diagrams to identify possible causes of the circuit short. CLEAR the DTCs. CYCLE the ignition key. REPEAT the self-test.

-------------------------------------------------
H5 CHECK CIRCUIT RCA09 (GN/VT) FOR AN OPEN


- Ignition OFF.
- Disconnect: ABS Module C135.
- Measure the resistance between steering wheel rotation sensor C226-1, circuit RCA09 (GN/VT), harness side and ABS module C135-12, circuit RCA09 (GN/VT), harness side.




- Is the resistance less than 5 ohms?

Yes
GO to H6.

No
REPAIR circuit RCA09 (GN/VT). CLEAR the DTCs. CYCLE the ignition key. REPEAT the self-test.

-------------------------------------------------
H6 CHECK CIRCUITS VCS06 (GY/BN) AND VCS07 (VT/OG) FOR A SHORT TO VOLTAGE


- Ignition ON.
- Measure the voltage between ground and:
- steering wheel rotation sensor C226-3, circuit VCS07 (VT/OG), harness side.
- steering wheel rotation sensor C226-2, circuit VCS06 (GY/BN), harness side.




- Is any voltage present?

Yes
REPAIR the affected circuit(s). CLEAR the DTCs. CYCLE the ignition key. REPEAT the self-test.

No
GO to H7.

-------------------------------------------------
H7 CHECK CIRCUITS VCS06 (GY/BN) AND VCS07 (VT/OG) FOR A SHORT TO GROUND


- Ignition OFF.
- Measure the resistance between ground and:
- steering wheel rotation sensor C226-3, circuit VCS07 (VT/OG), harness side.
- steering wheel rotation sensor C226-2, circuit VCS06 (GY/BN), harness side.




- Are the resistances greater than 10,000 ohms?

Yes
GO to H8.

No
REPAIR the affected circuit(s). CLEAR the DTCs. CYCLE the ignition key. REPEAT the self-test.

-------------------------------------------------
H8 CHECK CIRCUITS VCS06 (GY/BN) AND VCS07 (VT/OG) FOR AN OPEN


- Measure resistance between the steering wheel rotation sensor C226, harness side and ABS module C135, harness side using the following chart:









- Is the resistance less than 5 ohms?

Yes
GO to H9.

No
REPAIR the affected circuit(s). CLEAR the DTCs. CYCLE the ignition key. REPEAT the self-test.

-------------------------------------------------
H9 CHECK CIRCUITS VCS06 (GY/BN) AND VCS07 (VT/OG) FOR A SHORT TOGETHER


- Measure the resistance between steering wheel rotation sensor C226-3, VCS07 (VT/OG), harness side and steering wheel rotation sensor C226-2, circuit VCS06 (GY/BN), harness side.




- Is the resistance greater than 10,000 ohms?

Yes
If sent here because DTC C1963 and/or C1975 are present, Go To Pinpoint Test I. Pinpoint Test I: DTCs C1279, C1280, C1281, C1282, C1963, C1975, C2769, C2770 And U0074

For all other instances, INSTALL a new steering wheel rotation sensor. REFER to Steering Wheel Rotation Sensor Service and Repair. CLEAR the DTCs. CYCLE the ignition key. REPEAT the self-test.

No
REPAIR the affected circuit(s). CLEAR the DTCs. CYCLE the ignition key. REPEAT the self-test.

-------------------------------------------------
pro multis Credits:Operation CHARM About Operation CHARM