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 carries out an electrical check of the hydraulic pump motor at start up and every 20 ms. DTC C1300 will set if any of the following conditions occur:
  • Hydraulic pump motor voltage supply failure occurs, such as an open circuit or open fuse.
  • The motor is shorted to ground.
  • The pump motor is commanded off, but pump motor return voltage is detected.
  • The pump motor is commanded on, but no pump motor return voltage is detected.
  • After the hydraulic pump motor has been running and then commanded off, the pump motor return voltage is checked for a locked or slow-spinning motor. If the pump motor return voltage drops too quickly after it was turned off, then an extended test is carried out which turns the pump motor on and off. After each transition, the pump motor return voltage is being monitored. If pump motor return voltage 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