Pinpoint Test C: DTC C1095
Anti-Lock Control
Pinpoint Tests
Pinpoint Test C: DTC C1095
Refer to Wiring Diagram Set 42, Vehicle Dynamic Systems for schematic and connector information. Diagrams By Number
Normal Operation
The operating voltage required to operate the hydraulic pump is in a range between 10 and 17 volts.
When the ignition key is turned to the ON position, the ABS module commands the Hydraulic Control Unit (HCU) pump on for 100 ms (±6 ms) and is then commanded off. After 6 ms, the ABS module reads the voltage that is being generated by the HCU pump. If the voltage indicates the motor is spinning at less than 500 rpm, there may be a locked motor. If this condition is detected 4 times, DTC C1095 is set.
- DTC C1095 (ABS Hydraulic Pump Motor Circuit Failure) - If during normal operation or the on-demand self test, the ABS module detects an open circuit, a short circuit to voltage or ground, or if there is an internal failure of the hydraulic pump motor or ABS module pump motor circuits, DTC C1095 is set.
This pinpoint test is intended to diagnose the following:
- Fuse
- Wiring, terminals or connectors
- HCU
- ABS module
PINPOINT TEST C: DTC C1095
NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.
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C1 CHECK THE ABS PUMP MOTOR
- Ignition ON.
- Is the ABS pump motor running all the time?
Yes
GO to C5.
No
GO to C2.
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C2 CHECK THE ABS MODULE PUMP MOTOR (PMP_MOTOR) ACTIVE COMMAND
- Connect the scan tool.
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: DataLogger - ABS Module .
- Toggle the PMP_MOTOR active command ON.
- Does the ABS pump motor run for approximately 2 seconds?
Yes
TOGGLE the PMP_MOTOR active command OFF. CLEAR the DTCs. CHECK the yellow ABS warning indicator while driving the vehicle (brakes must not be applied) at greater than 40 km/h (25 mph). If the yellow ABS warning indicator illuminates, RETRIEVE the DTCs. If DTC C1095 is retrieved, GO to C5.
No
TOGGLE the PMP_MOTOR output command OFF. GO to C3.
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C3 CHECK THE PUMP MOTOR VOLTAGE SUPPLY TO THE ABS MODULE
- Ignition OFF.
- Disconnect: ABS Module C135.
- Measure the voltage between ABS module C135-1, circuit SBB69 (GY/RD), harness side and ground.
- Is the voltage greater than 10 volts?
Yes
GO to C4.
No
VERIFY that BJB fuse 69 (60A) is OK. If OK, REPAIR circuit SBB69 (GY/RD). If not OK, REFER to the Wiring Diagrams to identify the possible causes of the circuit short. CLEAR the DTCs. REPEAT the self-test. Diagrams By Number
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C4 CHECK THE ABS MODULE GROUND CIRCUIT FOR AN OPEN
- Measure the resistance between ABS module C135-16, circuit GD120 (BK/GN), harness side and ground.
- Is the resistance less than 5 ohms?
Yes
INSTALL a new HCU. REFER to Hydraulic Control Unit (HCU) Service and Repair. CLEAR the DTCs. REPEAT the self-test.
No
REPAIR circuit GD120 (BK/GN). CLEAR the DTCs. REPEAT the self-test.
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C5 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 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. REPEAT the self-test.
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