DTC 63 Valve Relay Fault: Notes

Valve relay provides power to 4 ABS valve solenoids and 2 TCS pilot valves (if applicable) in BPM valve. Valve relay is located on BPM valve, and may be replaced if found to be defective.

Valve relay is engaged during normal system operation. When ignition switch is turned to RUN position, EBTCM/EBCM commands valve relay on by grounding valve relay actuation line on circuit No. 856. When this ground is provided, valve relay is energized from voltage supply on circuit No. 854. Valve relay switches and battery voltage is provided to 4 valve solenoids, pilot valves and valve relay voltage sense line on circuit No. 886. Valve relay remains engaged until ignition is turned off or a failure is detected.

Valve relay voltage feedback provides suppression of voltage spikes created during operation of both front ABS valve solenoids during anti-lock and traction control.

When valve relay is engaged, valve relay sense line should be at battery voltage. With valve relay disengaged, sense line should be at ground. If commanded position of valve relay and position indicated by sense line do not agree, DTC 63 will set. Some conditions that cause DTC 63 to set are:

• Open circuit on circuits No. 886 or 856.
• Short to battery voltage on circuits No. 886 and 856.
• Short to ground on circuits No. 886 or 856.
• Defective solenoid valve relay.
• Open circuit in circuit No. 854.
• Loss of voltage to BPM valve terminals No. 6 and 12 during pump run.
  NOTE: Test numbers refer to numbers on diagnostic chart.
  1. Checks for battery voltage to valve relay through fuse No. 5 and circuit No. 1042.
  2. Checks for possible loss of voltage when system is under load.
  3. Checks valve relay coil for proper resistance.
  4. Checks for valve relay contacts being internally open when in relay unenergized position. 5a) Checks for valve relay contacts being stuck open when in relay energized position. 5b) Checks integrity of valve relay circuitry internal to BPM valve.
  5. Checks for open in ground circuit No. 250.
  6. Checks for open in circuit No. 886.
  7. Checks for an open between splice No. S140 and EBTCM/EBCM terminal No. 23.
  8. Checks for short to ground in circuit No. 886.
  9. Checks for short to system voltage in circuit No. 886.
  10. Checks for an open in circuit No. 854.
  11. Checks for a short to ground in circuit No. 854.
  12. Checks for short to system voltage in circuit No. 854.
  13. Checks for an open in circuit No. 856.
  14. Checks for a short to ground in circuit No. 856.
  15. Checks for a short to system voltage in circuit No. 856.
  16. Checks wiring and connectors for intermittents.
  17. Checks whether DTC was set due to an intermittent condition or EBTCM/EBCM fault.
  18. Checks if problem found in step 13) is caused by short to system voltage in circuit No. 874, 856 or 854.