Circuit Description
Solenoid valve relay provides power to 3 solenoid valves in hydraulic modulator. Solenoid valve relay is located on hydraulic modulator and can be replaced separately.
Valve relay is engaged during normal system operation. When ignition switch is in RUN position, EBCM commands solenoid valve relay on by grounding relay actuation line on circuit No. 879. When ground is provided, valve relay is energized from voltage supply line on circuit No. 1079. Valve relay switches, and battery voltage is provided to 3 solenoid valves and solenoid valve feedback line on circuit No. 851. Valve relay remains engaged until ignition switch is turned OFF or a failure is detected.
Code 63 will be set if commanded position of valve relay and valve relay position indicated by feedback line do not agree. Conditions which could cause a code 63 to set are an open circuit on circuits No. 851 or 879, a short to voltage on circuits No. 851 or 879, a short to ground on circuits No. 851 or 879, defective solenoid valve relay, or open circuit on circuit No. 854.