P1593

P1593-SPEED CONTROL SWITCH STUCK







- When Monitored:
Ignition on.

- Set Condition:
S/C Switch is mechanically stuck in the On/Off, Resume/Accel, or Set position for too long. One trip fault.





1. SPEED CONTROL SWITCH STATUS
1. Start the engine.
2. With the scan tool, monitor each switch function for the Speed Control Switches.
3. Press and release each Speed Control Button.
- Resume/Accel
- Cancel
- Decel (Coast)
- On/Off
- Set

Does each switch function change status when pressing and then depressing each switch?

Yes

- Perform the INTERMITTENT CONDITION diagnostic procedure. Intermittent Condition Test

No

- Go To 2

2. SPEED CONTROL SWITCHES
1. Turn the ignition off.
2. Remove the Speed Control Switches from the steering wheel.
3. Measure the resistance across each Switch Control Switch.
4. Monitor the ohmmeter while pressing each function button on each switch.
- Resume/Accel - 15,400 ohms
- Cancel - 909 +/- 9 ohms
- Decel (Coast) - 2940 +/- 30 ohms
- On/Off - 0 ohms
- Set - 6650 +/- 66 ohms

Does the function on the Speed Control Switches have the correct resistance value?

Yes

- Go To 3

No

- Replace the Speed Control Switch that had the incorrect resistance value.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

3. (V71) S/C SWITCH NO. 1 SIGNAL SHORTED TO BATTERY VOLTAGE




1. Measure the voltage on the (V71) S/C Switch No. 1 Signal at the Speed Control harness connector.

Is the is the voltage above 5.0 volts?

Yes

- Repair the short to battery voltage in the (V71) S/C Switch No. 1 Signal.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

No

- Go To 4

4. (V71) S/C SWITCH NO. 1 SIGNAL OPEN





NOTE: The measurement must be taken from both Speed Control Switch 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.

1. Measure the resistance of the (V71) S/C Switch No. 1 Signal from the Speed Control harness connector to the appropriate terminal of special tool #8815.

Is the resistance below 5.0 ohms for both measurement?

Yes

- Go To 5

No

- Repair the open in the (V71) S/C Switch No. 1 Signal.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

5. V937/K914 S/C SWITCH RETURN OPEN





NOTE: The measurement must be taken from both Speed Control Switch 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.

1. Measure the resistance of the V937/K914 S/C Switch Return circuit from the Speed Control harness connector to the appropriate terminal of special tool #8815.

Is the resistance below 5.0 ohms for both measurements?

Yes

- Go To 6

No

- Repair the open in the V937/K914 S/C Switch Return circuit.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

6. PCM

NOTE: Before continuing, check the PCM harness connector terminals for corrosion, damage or terminal push out. Repair as necessary.

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

If there are no possible causes remaining, view repair.

Repair

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