P0593

P0593-SPEED CONTROL SWITCH 2 CIRCUIT HIGH





For complete wiring diagrams refer to Diagrams/Electrical.


- When Monitored:

Key on or Engine running.

- Set Condition:

Speed Control MUX switch above 11.5 volts for 5 seconds.







Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding.

Diagnostic Test


1. SCAN TOOL SHOWS SPEED CONTROL SWITCH ON/OFF

Turn the ignition on.

With the scan tool in Inputs/Outputs, read the Speed Control inputs state in ECM.

While monitoring the scan tool, push the Speed Control On/Off Switch several times, then leave it on.

Did the scan tool show Speed Control Switch off and on?

Yes

- Go To 2

No

- Test Complete.

2. S/C WIRING HARNESS OBSERVABLE PROBLEM

Turn the ignition off.

Using the Schematics as a guide, inspect the Wiring and Connectors.

Were any problems found?

Yes

- Repair as necessary.
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

No

- Go To 3

3. STEERING COLUMN CONTROL MODULE









Disconnect the C1 and C3 SCCM harness connectors.


NOTE: Check connectors - Clean/repair as necessary.

Measure the resistance of the (V937) S/C Switch Return circuit between the C1 and C3 SCCM harness connectors.

Measure the resistance of the (V38) S/C Switch 2 Signal circuit between the C1 and C3 SCCM harness connectors.

Was the resistance above 5.0 ohms for either circuit?

Yes

- Replace the Steering Column Control Module.
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

No

- Go To 4

4. SPEED CONTROL ON/OFF SWITCH

Disconnect the Speed Control On/Off Switch harness connector only.


NOTE: Check connectors - Clean/repair as necessary.

Measure the resistance across the S/C On/Off Switch.

Is the resistance between 20.3K and 20.7K ohms?

Yes

- Go To 5

No

- Replace the On/Off Switch.
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

5. (V38) S/C SWITCH 2 SIGNAL CIRCUIT SHORTED TO VOLTAGE

Turn the ignition on.

Measure the voltage of the (V38) S/C Switch 2 Signal circuit at both S/C Switch harness connectors.

Is the voltage above 6.0 volts?

Yes

- Repair the (V38) S/C Switch 2 Signal circuit for a short to voltage.
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

No

- Go To 6

6. (V38) S/C SWITCH 2 SIGNAL CIRCUIT OPEN ECM TO SCCM

Turn the ignition off.

Disconnect the ECM harness connector.


NOTE: Check connectors - Clean/repair as necessary.

Measure the resistance of the (V38) S/C Switch Signal 2 circuit between the ECM connector and the C1 SCCM harness connector.

Is the resistance below 5.0 ohms?

Yes

- Go To 7

No

- Repair open in the (V38) S/C Switch 2 Signal circuit between the ECM and the SCCM.
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

7. (V38) S/C SWITCH 2 SIGNAL CIRCUIT OPEN SCCM TO S/C SWITCH

Measure the resistance of the (V38) S/C Switch 2 Signal circuit from the C3 SCCM harness connector to the S/C Switch harness connectors.

Is the resistance below 5.0 ohms?

Yes

- Go To 8

No

- Repair the open in the (V38) S/C Switch 2 Signal circuit between the Steering Column Control Module and the S/C switches.
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

8. (V937) S/C SWITCH RETURN CIRCUIT OPEN BETWEEN THE SCCM AND S/C SWITCHES

Measure the resistance of the (V937) S/C Switch Return circuit between the S/C harness connectors to the C3 SCCM harness connector.

Is the resistance below 5.0 ohms?

Yes

- Go To 9

No

- Repair open in the (V937) S/C Switch Return circuit from Steering Column Control Module to the S/C switches.
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

9. (V937) S/C SWITCH RETURN CIRCUIT OPEN BETWEEN THE ECM AND SCCM

Measure the resistance of the (V38) S/C Switch Return circuit between the ECM harness connector and the C1 SCCM harness connector.

Is the resistance below 5.0 ohms?

Yes

- Replace and program the ECM.
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

No

- Repair open in the (V937) S/C Switch Return circuit between the ECM and Steering Column Control Module.
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test