C1096
Anti-Lock Control - Three-Channel
Pinpoint Test C: DTCs C1095 and C1096
Normal Operation
Fused battery voltage for the Hydraulic Control Unit (HCU) pump motor is supplied to the ABS module by Battery Junction Box (BJB) fuse 96 (50A). The ABS module supplies the voltage and ground for the pump motor. The 2 components are hardwired together; there are no connectors or wiring harnesses between the 2 components.
When the ignition key is turned to the ON position, the ABS module commands the HCU (Hydraulic Control Unit) pump on for 100 ms (±6 ms), then commands it off. After 6 ms, the ABS module reads the voltage that is being generated by the HCU (Hydraulic Control Unit) pump.
- DTC C1095 (ABS Hydraulic Pump Motor Circuit Failure)- a continuous and on-demand DTC that sets if a short to voltage or ground is detected, if a locked up pump motor is detected or if there is an internal failure of the ABS module. 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 sets.
- DTC C1096 (ABS Hydraulic Pump Motor Circuit Open)- a continuous and on-demand DTC that sets if an open circuit is detected. The pump motor is checked for an open circuit 2 seconds after the most recent successful pump motor off command. The ABS module sends a reference voltage to the pump motor and looks for a voltage drop. If voltage feedback remains greater than 0.75 volt for more than 50 ms (±6 ms) after these conditions have been met, DTC C1096 sets.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Hydraulic pump motor
- ABS module
PINPOINT TEST C : DTCs C1095 AND C1096
NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.
NOTE: Failure to disconnect the battery when instructed results in false resistance readings.
C1 CHECK FOR ABS MODULE ON-DEMAND DTCs
- Ignition ON.
- Using the scan tool, clear all ABS module DTCs.
- Ignition OFF.
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: Self Test- ABS Module.
- Retrieve and record all ABS module DTCs.
Is DTC C1095 or C1096 present?
Yes
GO to C2.
No
For all other DTCs, REFER to the ABS Module DTC Chart - Three-Channels. Anti-Lock Control - Three-Channel
If no other DTCs are set, the system is operating correctly at this time.
C2 CHECK THE ABS PUMP MOTOR
- Listen for the ABS pump motor.
Is the ABS pump motor running continuously?
Yes
INSTALL a new ABS module. REFER to Anti-Lock Brake System (ABS) Module . TEST the system for normal operation.
No
GO to C3.
C3 CHECK THE ABS PUMP MOTOR CONTROL OUTPUT COMMAND (ABS_MTR)
- Enter the following diagnostic mode on the scan tool: DataLogger- ABS Module.
- Toggle the ABS_MTR output command ON.
Does the HCU (Hydraulic Control Unit) pump motor run for approximately 2 seconds?
Yes
TOGGLE the ABS_MTR output command OFF. GO to C4.
No
TOGGLE the ABS_MTR output command OFF. GO to C5.
C4 CHECK FOR RETURNING ABS MODULE DTCs
- Using the scan tool, clear all ABS module DTCs.
- Cycle the ignition switch and test drive the vehicle above 32 km/h (20 mph).
- Enter the following diagnostic mode on the scan tool: Self Test- ABS Module.
Are any DTCs present?
Yes
If DTC C1096 is present, GO to C7.
If DTC C1095 is present, INSTALL a new HCU (Hydraulic Control Unit). REFER to Hydraulic Control Unit (HCU) . CLEAR the DTCs. REPEAT the self-test.
If the concern is still present, GO to C8.
For all other ABS module DTCs, REFER to the ABS Module DTC Chart - Three-Channel. Anti-Lock Control - Three-Channel
No
The system is operating correctly at this time.
C5 CHECK THE VOLTAGE TO THE ABS MODULE FOR PUMP MOTOR ACTIVATION
- Ignition OFF.
- Disconnect: ABS Module C135.
- Measure the voltage between ABS module C135-1, circuit SBB96 (VT/RD), harness side and ground.
Is the voltage greater than 10 volts?
Yes
GO to C6.
No
VERIFY BJB (Battery Junction Box) fuse 96 (50A) is OK. If OK, REPAIR circuit SBB96 (VT/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. [1][2]Diagrams By Number
C6 CHECK GROUND CIRCUITS FOR CONTINUITY
- Ignition OFF.
- Disconnect: Battery Negative Cable.
- Measure the resistance between the ABS module C135-13, circuit GD163 (BK/GY), harness side and ground; and between the ABS module C135-38, circuit GD163 (BK/GY), harness side and ground.
Are the resistances less than 5 ohms?
Yes
GO to C7.
No
REPAIR circuit GD163 (BK/GY). CLEAR the DTCs. REPEAT the self-test.
C7 CHECK THE ABS MODULE GROUND EYELET AT THE CHASSIS
- Remove the bolt retaining G135 on the LT frame rail.
- Clean the body mating surface and ground eyelets.
- Install the ground eyelet to the chassis with the retaining bolt.
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: Self Test- ABS Module.
Is DTC C1095 or C1096 retrieved?
Yes
INSTALL a new HCU (Hydraulic Control Unit). REFER to Hydraulic Control Unit (HCU) . CLEAR the DTCs. TEST the system for normal operation.
If the concern is still present, GO to C8.
No
The concern was caused by a loose or corroded connector. CLEAR the DTCs. REPEAT self-test.
C8 CHECK FOR CORRECT ABS MODULE OPERATION
- Disconnect the ABS module connector.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect the ABS module connector and make sure that it seats 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 .
No
The system is operating correctly at this time. TEST the system for normal operation.