Pinpoint Test C: DTCs C1145 (RF), C1155 (LF), C1175 (REAR)
Anti-Lock Control
Pinpoint Tests
Pinpoint Test C: DTCs C1145 (RF), C1155 (LF), C1175 (REAR)
Refer to Wiring Diagram Set 42, Vehicle Dynamic Systems for schematic and connector information. Diagrams By Number
Normal Operation
The active wheel speed sensors generate a square wave signal that is sent to the ABS module. The wheel speed sensor circuitry connects to the ABS module through 2 wires and a connector at each wheel speed sensor. When the ignition is turned to the RUN position, the ABS module carries out a self-test by sending a reference voltage to all of the wheel speed sensors and their circuitry to determine if they are functional.
Voltage and ground signals are supplied to the wheel speed sensors from the ABS module.
- DTC C1145 (Wheel Speed Sensor RF Input Circuit Failure) - When the vehicle speed exceeds 5 km/h (3 mph), if the ABS module detects an open, short to ground or voltage or a defective RF wheel speed sensor trigger circuit, DTC C1145 will be set.
- DTC C1155 (Wheel Speed Sensor LF Input Circuit Failure) - When the vehicle speed exceeds 5 km/h (3 mph), if the ABS module detects an open, short to ground or voltage or a defective LF wheel speed sensor trigger circuit, DTC C1155 will be set.
- DTC C1175 (Wheel Speed Sensor Rear Input Circuit Failure) - When the vehicle speed exceeds 5 km/h (3 mph), if the ABS module detects an open, short to ground or voltage or a defective rear wheel speed sensor trigger circuit, DTC C1175 will be set.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Wheel speed sensor
- ABS module
PINPOINT TEST C: DTCs C1145 (RF), C1155 (LF), C1175 (REAR)
NOTICE: Use the Flex Probe Kit for all test connections to prevent damage to the wiring terminals. Do not use standard multi-meter probes.
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C1 CHECK FOR FAULT REPEATABILITY
NOTE: Both circuits must be checked for each DTC.
- Connect the scan tool.
- Enter the following diagnostic mode on the scan tool: Clear the CMDTCs.
- Drive the vehicle at least 16 km/h (10 mph).
- Retrieve and document Continuous Memory Diagnostic Trouble Codes (CMDTCs).
- Is DTC C1145, C1155 or C1175 retrieved?
Yes
If the Rotunda Active Wheel Speed Sensor Tester is not available, GO to C4.
If the Rotunda Active Wheel Speed Sensor Tester is available, GO to C2.
No
INSPECT the wheel speed sensors, wheel speed sensor wiring and wheel speed sensor tone rings. REPAIR or INSTALL new as necessary. If any other DTCs are retrieved, GO to the ABS Module DTC Chart. Diagnostic Trouble Code Tests and Associated Procedures
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C2 CHECK THE ABS MODULE OUTPUT USING THE ROTUNDA ACTIVE WHEEL SPEED SENSOR TESTER
- Ignition OFF.
- Disconnect: Suspect Wheel Speed Sensor.
- Connect the Rotunda Active Wheel Speed Sensor Tester to the wheel speed sensor connectors.
- Ignition ON.
- Select the correct system polarity on the tester and turn the tester power switch to the ON position.
- Is the module output LED illuminated?
Yes
GO to C3.
No
GO to C6.
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C3 CHECK THE WHEEL SPEED SENSOR OUTPUT WITH THE ROTUNDA ACTIVE WHEEL SPEED SENSOR TESTER
- Raise the suspect wheel until it can spin freely. Refer to Vehicle Jacking and Lifting.
- While monitoring the Rotunda Active Wheel Speed Sensor Tester, slowly spin the suspect wheel.
- Do the tester output LEDs illuminate and flash and is the current overload LED not illuminated?
Yes
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.
No
If the current level LED is not illuminated and the sensor output LEDs do not illuminate or if the current level LED is illuminated red, INSTALL a new wheel speed sensor. For the front wheel speed sensor, REFER to Wheel Speed Sensor - Front, Rear Wheel Drive (RWD) Wheel Speed Sensor - Front or Wheel Speed Sensor - Front, Four Wheel Drive (4WD) Wheel Speed Sensor - Front. For the rear wheel speed sensor, REFER to Wheel Speed Sensor - Rear Wheel Speed Sensor - Rear. CLEAR the DTCs. REPEAT the self-test.
If the current level LED is not illuminated and the sensor output LEDs illuminate green but do not flash, INSPECT the wheel speed sensor tone ring and INSTALL new if necessary. If the tone ring is OK, INSTALL a new wheel speed sensor. For the front wheel speed sensor, REFER to Wheel Speed Sensor - Front, Rear Wheel Drive (RWD) Wheel Speed Sensor - Front or Wheel Speed Sensor - Front, Four Wheel Drive (4WD) Wheel Speed Sensor - Front. For the rear wheel speed sensor, REFER to Wheel Speed Sensor - Rear Wheel Speed Sensor - Rear. CLEAR the DTCs. REPEAT the self-test.
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C4 CHECK THE WHEEL SPEED SENSOR CIRCUITS FOR A SHORT TO VOLTAGE
NOTE: Both circuits must be checked for each DTC.
- Ignition OFF.
- Disconnect: ABS Module C135 .
- Disconnect: Suspect Wheel Speed Sensor.
- Ignition ON.
- For DTC C1145: measure the voltage between ground and:
- ABS module C135-26, circuit VCA05 (GY/VT), harness side.
- ABS module C135-27, circuit RCA19 (VT), harness side.
- For DTC C1155: measure the voltage between ground and:
- ABS module C135-12, circuit VCA03 (VT/WH), harness side.
- ABS module C135-13, circuit RCA17 (YE), harness side.
- For DTC C1175: measure the voltage between ground and:
- ABS module C135-42, circuit VCA07 (BU/OG), harness side.
- ABS module C135-41, circuit RCA21 (BN/GN), harness side.
- Is any voltage present?
Yes
REPAIR the affected circuit(s). CLEAR the DTCs. REPEAT the self-test.
No
GO to C5.
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C5 CHECK THE WHEEL SPEED SENSOR CIRCUITS FOR A SHORT TO GROUND
- Ignition OFF.
- For DTC C1145: measure the resistance between ground and:
- ABS module C135-26, circuit VCA05 (GY/VT), harness side.
- ABS module C135-27, circuit RCA19 (VT), harness side.
- For DTC C1155: measure the resistance between ground and:
- ABS module C135-12, circuit VCA03 (VT/WH), harness side.
- ABS module C135-13, circuit RCA17 (YE), harness side.
- For DTC C1175: measure the resistance between ground and:
- ABS module C135-42, circuit VCA07 (BU/OG), harness side.
- ABS module C135-41, circuit RCA21 (BN/GN), harness side.
- Are the resistances greater than 10,000 ohms?
Yes
GO to C6.
No
REPAIR the affected circuit(s). CLEAR the DTCs. REPEAT the self-test.
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C6 CHECK THE WHEEL SPEED SENSOR CIRCUITS FOR AN OPEN
- Ignition OFF.
- Disconnect: ABS Module C135.
- Disconnect: Suspect Wheel Speed Sensor.
- For DTC C1145: measure the resistance between:
- ABS module C135-26, circuit VCA05 (GY/VT), harness side and RF wheel speed sensor C160-1, circuit VCA05 (GY/VT), harness side.
- ABS module C135-27, circuit RCA19 (VT), harness side and RF wheel speed sensor C160-2, circuit RCA19 (VT), harness side.
- For DTC C1155: measure the resistance between:
- ABS module C135-12, circuit VCA03 (VT/WH), harness side and LF wheel speed sensor C150-1, circuit VCA03 (VT/WH), harness side.
- ABS module C135-13, circuit RCA17 (YE), harness side and LF wheel speed sensor C150-2, circuit RCA17 (YE), harness side.
- For DTC C1175: measure the resistance between:
- ABS module C135-42, circuit VCA07 (BU/OG), harness side and rear wheel speed sensor C455-1, circuit VCA07 (BU/OG), harness side.
- ABS module C135-41, circuit RCA21 (BN/GN), harness side and rear wheel speed sensor C455-2, circuit RCA21 (BN/GN), harness side.
- Are the resistances less than 5 ohms?
Yes
GO to C7.
No
REPAIR the affected circuit(s). CLEAR the DTCs. REPEAT the self-test.
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C7 CHECK FOR SHORTED WHEEL SPEED SENSOR CIRCUITS
- Measure the resistance between suspect front wheel speed sensor pins, harness side.
- Measure the resistance between rear wheel speed sensor pins, harness side.
- Is the resistance greater than 10,000 ohms?
Yes
GO to C8.
No
REPAIR the affected circuit(s). CLEAR the DTCs. REPEAT the self-test.
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C8 CHECK THE ABS MODULE OUTPUT
- Connect: ABS Module C135.
- Ignition ON.
- Measure the voltage between the suspect front wheel speed sensor pins, harness side.
- Measure the voltage between the rear wheel speed sensor pins, harness side.
- Are the voltages greater than 10 volts?
Yes
INSTALL a new wheel speed sensor. For the front wheel speed sensor, REFER to Wheel Speed Sensor - Front, Rear Wheel Drive (RWD) Wheel Speed Sensor - Front or Wheel Speed Sensor - Front, Four Wheel Drive (4WD) Wheel Speed Sensor - Front. CLEAR the DTCs. REPEAT the self-test. For the rear wheel speed sensor, REFER to Wheel Speed Sensor - Rear Wheel Speed Sensor - Rear. CLEAR the DTCs. REPEAT the self-test.
No
GO to C9.
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C9 CHECK THE ABS MODULE CONNECTORS
- Disconnect the ABS connector.
- Check for:
- corrosion.
- pushed-out pins.
- spread terminals.
- Connect the ABS connector and make sure that it is seated correctly.
- 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. CLEAR the DTCs. REPEAT the self-test.
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.
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