DTC C0498
Circuit Description
The electronic variable orifice (EVO)/Passlock™ module supplies a 0-850 milliamperes percentage duty cycle current to the steering assist control solenoid. The current extends or retracts the actuator valve inside the solenoid. The extension or retraction will regulate an orifice on the power steering pump. The regulated orifice will cause the fluid flow output to modulate. The fluid flow output will increase or decrease in steering wheel effort. Supplying a 0 milliampere to the steering valve control solenoid will fully retract the valve. This provides the maximum fluid flow and power steering assist. Suppling 850 milliamperes to the steering assist control solenoid extends the valve. The extended valve will decrease the fluid flow and minimize the power steering assist. The EVO/Passlock™ module constantly adjusts the current flow to the steering assist control solenoid based on the vehicle speed and the steering wheel position. The adjusting current flow provides vehicle speed related power steering assist.
Conditions for Setting the DTC
| • | There is a short to ground in CKT 1294 (WHT). |
| • | When cycling the ignition switch to the OFF position and then to the ON position. |
| • | The conditions must be met for 1 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 cause the solenoid valve to retract. The retracting valve will provide the maximum fluid flow and full power steering assist at all time.
Conditions for Clearing the MIL/DTC
| • | A history DTC will clear after 100 consecutive ignition cycles occur without a fault. |
| • | Use a scan tool in order to clear the history and the current DTC(s). |
Diagnostic Aids
| • | The following conditions may cause an intermittent problem: |
| - | A poor connection. |
| - | A break in the wire insulation that exposes the internal wire. |
| - | A wire that is broken on the inside of the insulation. |
| • | Thoroughly check the EVO/Passlock™ module and the vehicle control module (VCM) for the following conditions: |
| - | Backed out terminals |
| - | Broken locks |
| - | Improperly formed terminals |
| - | Damaged terminals |
| - | Weak terminal retaining tension |
| - | Proper routing |
| • | The steering assist control solenoid valve may be stuck. The stuck valve provides uncalculated power steering assist. |
| Refer to Power Steering System Test in Power Steering System. |
Test Description
The number(s) below refer to the step number(s) on the diagnostic table.
-
This step ensures that you perform the Diagnostic System Check.
-
This step checks for a short to voltage in CKT 1294 (WHT) with the EVO/Passlock™ module disconnected.
-
This step 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 CKT 1294 (WHT).
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
Did you perform the Diagnostic System Check? | -- | Go to Step 2 | Go to the Diagnostic System Check | |
Did the voltmeter display a voltage? | Greater than 1.0 volt | Go to Step 3 | Go to Step 7 | |
Did the J 39200 DMM display a voltage? | Greater than 1.0 volt | Go to Step 5 | Go to Step 4 | |
4 |
Did the J 39200 DMM display the specified resistance values? | 7-15ohms | Go to Step 7 | Go to Step 6 |
5 | Repair the short to voltage in CKT 1294 (WHT). Is the repair complete? | -- | Go to Step 9 | -- |
6 | Replace the steering assist control solenoid. Refer to Power Steering Solenoid Actuator and Discharge Fitting Replacement . Is the repair complete? | -- | Go to Step 9 | -- |
7 |
Did you find a problem? | -- | Go to Step 5 | Go to Step 8 |
8 | Replace the EVO/Passlock™ module. Refer to Elec Variable Orifice Passlock Module Replacement . Is the replacement complete? | -- | Go to Diagnostic System Check | -- |
9 |
Is the repair complete? | -- | Go to the Diagnostic System Check | -- |
