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