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Home >> Mercury >> 2009 >> Grand Marquis V8-4.6L Flex Fuel >> Repair and Diagnosis >> Brakes and Traction Control >> Antilock Brakes / Traction Control Systems >> Testing and Inspection >> Pinpoint Tests >> Pinpoint Test B: DTCs C1145, C1155, C1165 And C1175

Pinpoint Test B: DTCs C1145, C1155, C1165 And C1175




Anti-Lock Control

Pinpoint Tests

Pinpoint Test B: DTCs C1145, C1155, C1165 and C1175

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

Normal Operation

The ABS module uses passive wheel speed sensors to determine wheel speed. These sensors consist of a permanent magnet wrapped with copper wiring. Each sensor is connected to the ABS module through 2 circuits, one for sensor return to the ABS module and one for sensor ground. As the teeth on the wheel speed sensor ring pass the sensor, the magnetic field of the sensor fluctuates and a voltage is produced. This voltage is sent back to the ABS module to indicate wheel speed. When the ignition key is turned to the RUN position, the ABS module will send a 5 volt reference voltage out to each sensor to check the condition of the circuit and the sensor. If the ABS module detects a fault condition (short to ground, short to voltage or open circuit) in either the sensor or circuitry, a DTC will be set.

The front wheel speed sensors are integral to the wheel hub and bearing assembly and have a serviceable jumper harness connecting the sensor to the main wire harness at C134 for the LF wheel speed sensor and C140 for the RF wheel speed sensor. The circuit colors for the LF sensor change from TN/OG and TN/BK to just BK at C134, and the circuit colors for the RF sensor change from YE/RD and YE/BK to just BK at C140.

DTC C1145-DTC C1175:





This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Front wheel speed sensor jumper harness
- Wheel speed sensor(s)
- ABS module



PINPOINT TEST B: DTCs C1145, C1155, C1165 AND C1175

NOTICE: The Flex Probe Kit must be used for all test connections. Use of standard multi-meter probes may damage wiring terminals.

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B1 CHECK THE SUSPECT WHEEL SPEED SENSOR FOR AN OPEN


NOTE: The rear wheel speed sensor connectors are located under the rear seat cushion.

- Disconnect: Suspect Wheel Speed Sensor.
- Measure the resistance between the suspect wheel speed sensor pin-1 and pin-2, component side.




- Is the resistance between 1,000 and 2,000 ohms for the front wheel speed sensors, and between 1,300 and 1,900 ohms for the rear wheel speed sensors?

Yes
CONNECT the wheel speed sensor. GO to B2.

No
For front wheel speed sensors, thoroughly INSPECT the front wheel speed sensor jumper harness. If the jumper harness is not OK, INSTALL a new jumper harness. If the jumper harness is OK, INSTALL a new front wheel speed sensor, REFER to Wheel Speed Sensor - Front Wheel Speed Sensor - Front. For rear wheel speed sensors, INSTALL a new rear wheel speed sensor, REFER to Wheel Speed Sensor - Rear Wheel Speed Sensor - Rear. CLEAR the DTCs. CARRY OUT the self-test with the brake pedal not applied.

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B2 CHECK THE WHEEL SPEED SENSOR CIRCUITS FOR A SHORT TO VOLTAGE


NOTE: To access the ABS module connector, remove the ACL assembly.

- Ignition OFF.
- Disconnect: ABS Module C135.
- Ignition ON.
- For DTC C1145 (RF), measure the voltage between ground and:
- ABS module C135-6, circuit 514 (YE/RD), harness side.
- ABS module C135-18, circuit 516 (YE/BK), harness side.




- For DTC C1155 (LF), measure the voltage between ground and:
- ABS module C135-22, circuit 521 (TN/OG), harness side.
- ABS module C135-21, circuit 522 (TN/BK), harness side.




- For DTC C1165 (RR), measure the voltage between ground and:
- ABS module C135-31, circuit 523 (RD/PK), harness side.
- ABS module C135-19, circuit 524 (PK/BK), harness side.




- For DTC C1175 (LR), measure the voltage between ground and:
- ABS module C135-20, circuit 518 (LG/RD), harness side.
- ABS module C135-33, circuit 519 (LG/BK), harness side.




- Is any voltage present?

Yes
REPAIR the affected circuit(s). CLEAR the DTCs. CARRY OUT the self-test with the brake pedal not applied.

No
GO to B3.

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B3 CHECK THE WHEEL SPEED SENSOR CIRCUITS FOR A SHORT TO GROUND


- Ignition OFF.
- For DTC C1145 (RF), measure the resistance between ground and:
- ABS module C135-6, circuit 514 (YE/RD), harness side.
- ABS module C135-18, circuit 516 (YE/BK), harness side.




- For DTC C1155 (LF), measure the resistance between ground and:
- ABS module C135-22, circuit 521 (TN/OG), harness side.
- ABS module C135-21, circuit 522 (TN/BK), harness side.




- For DTC C1165 (RR), measure the resistance between ground and:
- ABS module C135-31, circuit 523 (RD/PK), harness side.
- ABS module C135-19, circuit 524 (PK/BK), harness side.




- For DTC C1175 (LR), measure the resistance between ground and:
- ABS module C135-20, circuit 518 (LG/RD), harness side.
- ABS module C135-33, circuit 519 (LG/BK), harness side.




- Are the resistances greater than 10,000 ohms?

Yes
GO to B4.

No
REPAIR the affected circuit(s). CLEAR the DTCs. CARRY OUT the self-test with the brake pedal not applied.

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B4 CHECK THE WHEEL SPEED SENSOR CIRCUITS FOR AN OPEN


NOTE: The rear wheel speed sensor connectors are located under the rear seat cushion.

- Disconnect: Suspect Wheel Speed Sensor(s) (disconnect the front wheel speed sensors at the wheel hub).
- Measure the resistance between the ABS module connector, harness side and the suspect wheel speed sensor connector, harness side as indicated in the following chart:

DTC C1145-DTC C1175:





- Are the resistances less than 5 ohms?

Yes
GO to B5.

No
REPAIR the affected circuit(s). CLEAR the DTCs. CARRY OUT the self-test with the brake pedal not applied.

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B5 CHECK FOR CORRECT ABS MODULE OPERATION


- Check ABS module connector C135 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 Service and Repair. 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. CARRY OUT the self-test with the brake pedal not applied.

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