Test C: DTC C1095 - ABS

Pinpoint Test C: DTC C1095 - ABS

Hydraulic Pump Motor Circuit Failure
Refer to Vehicle/Diagrams, Vehicle Dynamic Systems for schematic and connector information.

Normal Operation
The operating voltage required for the ABS module to operate the hydraulic pump is in a range between 10 and 16 volts.

Fused battery voltage for hydraulic pump motor operation is supplied to the ABS module by battery junction box (BJB) fuse 9 (40A) along circuit SBB09 (RD). Ground for all ABS operations is provided along circuit GD122 (BK).

The ABS module performs 2 different tests to determine pump motor condition. The first test is done when the ignition key is turned to the ON position and is used to test for a pump motor that may be locking up. The ABS module commands the HCU pump motor on for 100 ms (�6 ms) and then commands the pump motor off. Once the pump motor is commanded off, it will generate a small amount of voltage. Six milliseconds after commanding the pump off, the ABS module will read the voltage that is being generated by the pump motor. If the voltage indicates the motor is spinning at less than 500 rpm, the motor may be locking up.

The second test is used to check for an open circuit and a short to voltage. Two seconds after the most recent (successful) pump motor off command, the ABS module will read the voltage that is being generated by the pump motor. If the voltage generated remains greater than 0.75 volt for more than 50 ms (�6 ms) after the off command, then a short to voltage may exist. If there is no voltage generated by the pump motor, then an open circuit condition may exist.

DTC C1095 ABS Hydraulic Pump Motor Circuit Failure - If during normal operation or the on-demand self test the ABS module detects a short to voltage or ground, a locked pump motor (must be detected 4 times) or an internal failure of the ABS module (short to voltage or ground), DTC C1095 will be set.

This pinpoint test is intended to diagnose the following:
^ Fuse
^ Wiring, terminals or connectors
^ Hydraulic control unit (HCU)
^ ABS module

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C3-C6:

C6 (Continued)-C7: