C0504

DTC C0504 - Steering Assist Control Solenoid Circuit High:

CIRCUIT DESCRIPTION
The EVO/Passlock Module supplies a 0-850 milliamperes PWM current (percent Duty Cycle) to the Steering Assist Control Solenoid. This current is used to extend or retract the actuator valve inside the solenoid. This in turn will regulate an orifice on the power steering pump, causing the fluid flow out-put to modulate. This results in an increase or decrease in steering wheel effort. With 0 milliampere supplied to the Steering Assist Control Solenoid, the valve will be fully retracted, providing maximum fluid flow and power steering assist. With 850 milliamperes supplied to the Steering Assist Control Solenoid, the valve will extend decreasing fluid flow and minimize power steering assist. The EVO/Passlock Module is constantly adjusting current flow to the Steering Assist Control Solenoid based on vehicle speed and steering wheel position, thus providing vehicle speed related power steering assist.

CONDITIONS FOR SETTING THE DTC
1. There is a short to voltage in BRN (1295) wire.
2. The ignition switch has been cycled to the OFF and then to the ON position.
3. The above conditions must be met for one second or longer.

ACTION TAKEN WHEN THE DTC SETS
The EVO/Passlock Module will not send any current to the Steering Assist Control Solenoid. This will result in the Steering Assist Control Solenoid valve to retract providing maximum fluid flow and full power steering assist at all times.

CONDITIONS FOR CLEARING THE DTC
1. A history DTC will clear after 100 consecutive ignition cycles have occurred without a fault.
2. History and current DTC(s) can be cleared by using the scan tool.

DIAGNOSTIC AIDS
^ An Intermittent problem may be caused by a poor connection, break in the wire insulation exposing the internal wire, or a wire that is broken inside the insulation.
^ The EVO/Passlock Module and the Vehicle Control Module (VCM) or Powertrain Control Module (PCM) should be thoroughly checked for terminals that have backed out, broken locks, improperly formed or damaged terminals, weak terminal retaining tension, or for proper routing.
^ The Steering Assist Control Solenoid valve may be stuck, providing uncalculated power steering assist.

TEST DESCRIPTION
The step numbers below refer to the same step numbers in the STEERING ASSIST CONTROL SOLENOID CIRCUIT HIGH DIAGNOSTIC TABLE.
^ Step 1 ensures that the Diagnostic System Check is performed.
^ Step 2 checks for short to voltage in BRN (1295) wire with the EVO/Passlock Module disconnected.
^ Step 3 checks the Steering Assist Control Solenoid harness for a short to voltage with the actuator disconnected.
- If voltage is indicated, there is a short to voltage on BRN (1295) wire.