C0500

CIRCUIT DESCRIPTION
The PSCM supplies a 0-850 milliamperes pulse width modulation current (percent Duty Cycle) to the power steering fluid flow actuator. 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 output to modulate. This results in an increase or decreased in steering wheel efforts. With 0 milliampere supplied to the power steering fluid flow actuator the valve will be fully retracted providing maximum fluid flow and power steering assist. With 850 milliamperes supplied to the power steering fluid flow actuator the. valve will extend decreasing fluid flow and minimize power steering assist. The PSCM is constantly adjusting current flow to the power steering fluid flow actuator based on vehicle speed and steering wheel position, thus providing vehicle speed related power steering assist.

CONDITIONS FOR SETTING THE DTC
When there is a open or short to ground, or short to voltage in CKTs 1294 or 1254 while the PSCM is pulsing the current to the power steering fluid flow actuator.
1. When voltage is below O volts.
2. When voltage is at battery voltage.
- The above conditions must be met for one second or longer.

ACTION TAKEN WHEN THE DTC SETS
The PSCM will not send any current to the power steering fluid flow actuator. This will result in the actuator 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 has occurred without a fault.
2. History and current DTC(s) can be cleared by using the Tech 2 scan tool.

DIAGNOSTIC AIDS
- If DTC's 502 or 503 are present, perform these codes first.
- 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 power Steering Control Module (PSCM) and the Vehicle Control Module (VCM) 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 solenoid valve may be stuck providing uncalculated power steering assist.








TEST DESCRIPTION
The Step numbers below refer to the same step numbers in the EVO Tracking Errors Diagnostic Table
- Step 1 ensures that the "Diagnostic System Check" is performed.
- Step 2 checks for short to voltage CKTs 1294 or 1295 with the PSCM disconnected.
- Step 3 checks for commanded and actual duty cycle.
- Step 4 checks the power steering fluid flow actuator harness for a short to voltage with the actuator disconnected on CATS 1294 and 1295.
- Step 6 checks the power steering fluid flow actuator harness for a short to ground or open with the actuator disconnected on CKTs 1294 and 1295.
- If voltage is indicated then there is a short to voltage on CAT 1294 or 1295.
- If voltage is 0 then there is a short to ground on CKT 1294 or 1295.