Diagnostic Test

1) ACTIVE DTC
Ignition on, engine not running.

With a scan tool, read DTCs.

Is the DTC active at this time?

Yes
1. Go To 2).
No
1. Refer to the INTERMITTENT CONDITION diagnostic procedure.
2. Perform (NGC) POWERTRAIN VERIFICATION TEST. (Refer to STANDARD PROCEDURE - NGC POWERTRAIN VERIFICATION TEST VER - 1) .
2) POWER STEERING PRESSURE SWITCH

Fig 1: CHECKING POWER STEERING SWITCH SIGNAL CIRCUIT
Courtesy of DAIMLERCHRYSLER CORP.

Turn the ignition off.

Disconnect the Power Steering Pressure Switch harness connector.

Ignition on, engine not running.

Connect a jumper wire to the (K66) P/S Switch Signal circuit at the Power Steering Pressure Switch harness connector.

Use the scan tool to monitor the Power Steering Pressure Switch status.

Touch the other end of the jumper wire to the (Z902) Ground circuit at the Power Steering Pressure Switch harness connector several times.

Did the Power Steering Pressure Switch status change from High to Low when connecting and disconnecting the jumper wire?

Yes
1. Replace the Power Steering Pressure Switch.
2. Perform the POWERTRAIN VERIFICATION TEST. (Refer to STANDARD PROCEDURE - POWERTRAIN VERIFICATION TEST) .
No
1. Go To 3).
  NOTE: Remove the jumper wire before continuing.
3) (K66) P/S SWITCH SIGNAL CIRCUIT OPEN
Turn the ignition off.

Disconnect the PCM harness connectors.

CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install Miller Special Tool #8815 to perform diagnosis.

Measure resistance of (K66) P/S Switch Signal circuit from the Power Steering Pressure Switch harness connector to the appropriate terminal of special tool #8815.

Is the resistance below 5.0 ohms?

Yes
1. Go To 4).
No
1. Repair the open in the (K66) P/S Switch Signal circuit.
2. Perform the POWERTRAIN VERIFICATION TEST. (Refer to STANDARD PROCEDURE - POWERTRAIN VERIFICATION TEST) .
4) (K66) P/S SWITCH SIGNAL CIRCUIT SHORTED TO GROUND

Fig 2: MEASURING RESISTANCE BETWEEN THE P/S SWITCH SIGNAL CIRCUIT AND GROUND
Courtesy of DAIMLERCHRYSLER CORP.

Measure the resistance between the (K66) P/S Switch Signal circuit in the Switch connector and ground.

Is the resistance below 100 ohms?

Yes
1. Repair the short to ground in the (K66) P/S Switch Signal circuit.
2. Perform the POWERTRAIN VERIFICATION TEST. (Refer to STANDARD PROCEDURE - POWERTRAIN VERIFICATION TEST) .
No
1. Go To 5).
5) (Z902) GROUND CIRCUIT OPEN

Fig 3: MEASURING RESISTANCE BETWEEN GROUND AND THE GROUND CIRCUIT
Courtesy of DAIMLERCHRYSLER CORP.

Measure the resistance between Ground and the (Z902) Ground circuit in the Power Steering Pressure Switch connector.

Is the resistance below 100 ohms?

Yes
1. Go To 6).
No
1. Repair the open in the (Z902) Ground circuit.
2. Perform the POWERTRAIN VERIFICATION TEST. (Refer to STANDARD PROCEDURE - POWERTRAIN VERIFICATION TEST) .
6) PCM
NOTE: Before continuing, check the PCM harness connector terminals for corrosion, damage, or terminal push out. Repair as necessary.

Using the schematics as a guide, inspect the wire harness and connectors. Pay particular attention to all Power and Ground circuits.

Were there any problems found?

Yes
1. Repair as necessary.
2. Perform the POWERTRAIN VERIFICATION TEST. (Refer to STANDARD PROCEDURE - POWERTRAIN VERIFICATION TEST) .
No
1. Replace and program the Powertrain Control Module per Service Information. Refer to MODULE-POWERTRAIN CONTROL and STANDARD PROCEDURE - PCM/ECM/SKREEM PROGRAMMING .
2. Perform the POWERTRAIN VERIFICATION TEST. (Refer to STANDARD PROCEDURE - POWERTRAIN VERIFICATION TEST)