Normal Operation

The operating voltage required for hydraulic pump operation is in a range between 10 and 16 volts.

Fused battery voltage is supplied to the ABS module for pump motor operation by Battery Junction Box (BJB) fuse 9 (40A) along circuit SBB09 (RD) and ground is provided along circuit GD120 (BK/GN).

• DTC C1300 (ABS Hydraulic Pump Motor Circuit Failure) - The ABS module conducts an electrical check of the hydraulic pump motor at every start up and every 20 milliseconds. DTC C1300 will set if any of the following conditions occur:
  • Hydraulic pump motor voltage supply failure occurs, such as an open circuit or fuse.
  • The hydraulic pump motor is shorted to ground.
  • The hydraulic pump motor is commanded off, but hydraulic pump motor voltage return is detected.
  • The hydraulic pump motor is commanded on, but no hydraulic pump motor voltage return is detected.
  • After the hydraulic pump motor has been on and then commanded off, the pump motor voltage return is checked in order to detect a locked or slow-spinning motor. If the pump motor voltage return drops too quickly after it was commanded off, the ABS module carries out an extended test which turns the pump motor on and off. After each transition, the pump motor voltage return is monitored. If the pump motor voltage return is too low 3 times in a row, then DTC C1300 will be set.

This pinpoint test is intended to diagnose the following: 

• Fuse
• Wiring, terminals or connectors
• ABS module