Pump/Motor Relay Output Circuit

NAME OF CODE:
Pump/Motor Relay Output Circuit

WHEN MONITORED:
The test is conducted on a continual basis when the pump/motor should be on.

SET CONDITION:
The pump/motor relay supplies power to the pump/motor located in the hydraulic control unit. It is controlled by the Controller, Anti-lock Brake (CAB) through cavity 16. The relay output voltage is monitored by the CAB at cavity 20. When the pump is off, the monitor line should be pulled low through the pump/motor windings to ground. When the pump is on the monitor line should be high. The trouble code is stored if voltage of the monitor line (cavity 20) is below 7 volts for 200 ms when the motor is commanded on for normal cycling or 100 ms during drive off test.

POSSIBLE CAUSES:
- Open pump/motor relay output circuit to pump
- Open pump/motor fuse in Power Distribution Center (PDC)
- Pump/motor relay output circuit shorted to ground
- Loose or corroded connector terminals
- Open fused B(+) circuit to relay
- Pump/motor seized
- Failed relay box