P0592
P0592-SPEED CONTROL SWITCH 2 CIRCUIT LOWP0592-Speed Control Switch 2 Circuit Low:
WHEN MONITORED
With the ignition key on.
SET CONDITION
Speed control switch input No.2 is below the minimum acceptable voltage at the PCM. One trip fault.
POSSIBLE CAUSES
- (V38) S/C Switch NO.2 signal circuit shorted to ground
- (V38) S/C Switch NO.2 signal circuit shorted to the (v937) switch return circuit
- Clockspring
- Speed control resume/accel switch
- Speed control on/off switch
- PCM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding.
DIAGNOSTIC TEST
1. SPEED CONTROL SWITCH VOLTAGE LOW
NOTE: Do not press any of the Speed Control Switch buttons.
Ignition on, engine not running.
With a scan tool, read the Speed Control voltage.
Q: Is the Speed Control voltage below 1.0 volt?
YES: Go To 2
NO: Refer to the INTERMITTENT CONDITION Diagnostic Procedure. Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
2. SPEED CONTROL ON/OFF SWITCH
With the scan tool, monitor the Speed Control Switch voltage.
Disconnect the Speed Control On/Off Switch harness connector.
Q: Did the voltage change to above 4.7 volts?
YES: Replace the Speed Control On/Off Switch. Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
NO: Go To 3
3. SPEED CONTROL RESUME/ACCEL SWITCH
With the scan tool, monitor the Speed Control Switch voltage.
Disconnect the Speed Control Resume/Accel Switch harness connector.
Q: Did the voltage change to above 4.7 volts?
YES: Replace the Speed Control Resume/Accel Switch. Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
NO: Go To 4
4. CLOCKSPRING
Turn the ignition off.
Disconnect the C1 Clockspring harness connector per Service Information.
Ignition on, engine not running.
With the scan tool, read the S/C Switch voltage.
Q: Did the S/C Switch volts change to 5.0 volts?
YES: Replace the Clockspring. Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
NO: Go To 5
5. V38) S/C SWITCH NO.2 SIGNAL CIRCUIT SHORTED TO GROUND
Turn the ignition off.
Connect the Clockspring harness connectors per Service Information.
Disconnect the C3 PCM harness connector.
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 the resistance between ground and the (V38) S/C Switch No.2 Signal circuit to the appropriate terminal of special tool #8815.
Q: Is the resistance below 100 ohms?
YES: Repair the short to ground in the (V38) S/C Switch No.2 Signal circuit. Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
NO: Go To 6
6. (V38) S/C SWITCH NO.2 SIGNAL CIRCUIT SHORTED TO THE (V937) SWITCH RETURN CIRCUIT
Measure the resistance between the (V937) Switch Return circuit and the (V38) S/C Switch No.2 Signal circuit in the Speed Control Switch.
Q: Is the resistance below 5.0 ohms?
YES: Repair the short between the (V38) S/C Switch No.2 Signal circuit and the (V937) Switch Return circuit. Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
NO: Go To 7
7. SPEED CONTROL SWITCH VOLTAGE VALUES
Connect the C3 PCM harness connector and the S/C Switch harness connectors.
Allow the engine to idle.
With a scan tool, monitor the S/C Switch voltage readings.
Take these same voltage measurements with a voltmeter by back probing the (V38) S/C Switch No.2 Signal circuit at the switches.
Compare the voltage readings on the voltmeter to what the scan tool displayed.
Q: Are the voltage readings out of the listed specification and is there less than a 0.2 of a volt difference between the voltmeter switch values and the scan tool switch values?
YES: Replace the Speed Control Switch. Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
NO: Go To 8
8. 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.
Q: Were there any problems found?
YES: Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
NO: Replace and program the Powertrain Control Module per Service Information. Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test