P0593-SPEED CONTROL SWITCH 2 CIRCUIT HIGH

For a complete wiring diagram Refer to Section 8W.

When Monitored:
With the ignition key on.
Set Condition:
Speed Control Switch No.2 input above the maximum acceptable voltage at the PCM. One trip fault.

Possible Causes

(V38) S/C SIGNAL NO.2 CIRCUIT SHORTED TO VOLTAGE

(V38) S/C SWITCH NO.2 SIGNAL CIRCUIT OPEN

(K914) SWITCH RETURN CIRCUIT OPEN

CLOCKSPRING

SPEED CONTROL SWITCH

PCM

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING).

Diagnostic Test

1.SPEED CONTROL SWITCH VOLTAGE HIGH

NOTE: Do not press any of the Speed Control Switch buttons.

Is the Speed Control voltage above 4.8 volts?

Yes

Go To 2

Refer to the INTERMITTENT CONDITION Diagnostic Procedure.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

2.SPEED CONTROL SWITCHES

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

Yes

Go To 3

Replace the Speed Control Switch that had the incorrect resistance value.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

3.CLOCKSPRING

Was the resistance above 5.0 ohms for either circuit?

Yes

Replace the Clockspring per Service Information.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

Go To 4

4.(V38) SIGNAL NO.2 CIRCUIT SHORTED TO BATTERY VOLTAGE

Is the voltage above 0 volts?

Yes

Repair the short to battery voltage in the (V38) S/C Signal No.2 circuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

Go To 5

5.(V38) S/C SWITCH NO.2 SIGNAL CIRCUIT SHORTED TO BATTERY VOLTAGE

Is the voltage above 0 volts?

Yes

Repair the short to battery voltage in the (V38) S/C Switch No.2 Signal circuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

Go To 6

6.(V38) S/C SWITCH NO.2 SIGNAL CIRCUIT OPEN

Is the resistance below 5.0 ohms?

Yes

Go To 7

Repair the open in the (V38) S/C Switch No.2 Signal circuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

7.(V38) S/C SWITCH NO.2 SIGNAL CIRCUIT OPEN

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.

Is the resistance below 5.0 ohms for both measurements?

Yes

Go To 8

Repair the open in the (V38) S/C Switch No.2 Signal circuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

8.(K914) S/C SWITCH RETURN CIRCUIT OPEN

Is the resistance below 5.0 ohms?

Yes

Go To 9

Repair the open in the (K914) S/C Switch Return circuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

9.(K914) S/C SWITCH RETURN CIRCUIT OPEN

Is the resistance below 5.0 ohms for both measurements?

Yes

Go To 10

Repair the open in the (K914) S/C Switch Return circuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

10.PCM

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

Were there any problems found?

Yes

Repair as necessary.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

Replace and program the Powertrain Control Module per Service Information.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)