For a complete wiring diagram Refer to Section 8W.When Monitored:Ignition on.Set Condition:Cruise Switch inputs are not coherent with each other. Example: PCM is reading Switch No.1 as Accel and Switch No.2 as Coast at the same time. One trip fault.Possible CausesS/C SWITCH SIGNAL CIRCUITS SHORTED TO BATTERY VOLTAGERESISTANCE IN THE S/C SWITCH SIGNAL CIRCUITSRESISTANCE IN THE (V937) S/C RETURN CIRCUITS/C SWITCH SIGNAL CIRCUITS SHORTED TO THE (V937) S/C RETURN CIRCUIT(V71) S/C SIGNAL 1 CIRCUIT SHORTED TO THE (V72) S/C SIGNAL 2 CIRCUITS/C SWITCH SIGNAL CIRCUITS SHORTED TO GROUNDSPEED CONTROL SWITCHPCMAlways perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING).1. ACTIVE DTCIgnition on, engine not running.This DTC is a two trip fault. If the scan tool indicates a one trip failure, the possible cause may have been the customer pressing the switch in two positions simultaneously. Test drive the vehicle and activate the Speed Control system. If the DTC matures to an active fault a repair is necessary.Ask the customer if it is possible that button was held in two positions at the same time before this DTC set. If this is the case, no repair is necessary.Start the engine.Allow the engine to reach normal operating temperature.With a scan tool, select View DTCs.It may be necessary to drive the vehicle to meet the conditions to set this DTC, try to repeat the conditions in which the fault originally set by reviewing the Freeze Frame data.Is the DTC Active or Pending at this time?YesGo To 2NoRefer to the INTERMITTENT CONDITION Diagnostic Procedure.Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)2. SPEED CONTROL SWITCHWith the scan tool, monitor the Speed Control Switch voltage.Disconnect the Speed Control Switch harness connector.Did the voltage change to above 4.8 volts?YesReplace the Speed Control Switch.Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)NoGo To 33. SPEED CONTROL SWITCHESTurn the ignition off.Remove and disconnect the Speed Control Switch from the steering wheel per Service Information.Measure the resistance across each Speed Control Switch.Monitor the ohmmeter while pressing each function button on each switch.The following resistance specs are taken between terminals (V72) S/C Signal 2 and (V937) S/C Return circuits of the Switch when holding the switch button in the following position.Not pressing any switch - 20.5 kohmsOn/Off - 8.87 kohmsSet - 0.825 kohmsCoast - 0.47 kohmsCancel - 3.92 kohmsResume/Accel - 1.87 kohmsThe following resistance specs are taken between terminals (V71) S/C Signal 1 and (V937) S/C Return circuits of the Switch when holding the switch button in the following positionNot pressing any switch - 20.5 kohmsOn/Off - 0.47 kohmsSet - 5.49 kohmsCoast - 2.94 kohmsCancel - 1.24 kohmsResume/Accel - 15.4 kohmsDoes the function on the Speed Control Switch have the correct resistance value?YesGo To 4NoReplace the Speed Control Switch that had the incorrect resistance value.Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)4. S/C SWITCH SIGNAL CIRCUIT SHORTED TO BATTERY VOLTAGE

Disconnect the C3 PCM harness connector.Measure the voltage on the (V71) and (V72) S/C Signal circuits at the Speed Control harness connector.Is the voltage above 5.0 volts?YesRepair the short to battery voltage in the (V71) or (V72) S/C Signal circuit.Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)NoGo To 55. S/C SWITCH SIGNAL CIRCUIT OPEN

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 of the (V71) and (V72) S/C Signal circuits from both Speed Control harness connector to the appropriate terminals of special tool #8815.Is the resistance below 5.0 ohms for each measurement?YesGo To 6NoRepair the excessive resistance in the (V71) or (V72) S/C Signal circuit.Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)6. (V937) SWITCH RETURN CIRCUIT OPEN

The measurement must be taken from both Speed Control Switch harness connectors.Measure the resistance of the (V937) S/C Return circuit at the Speed Control harness connector to the appropriate terminal of special tool #8815.Is the resistance below 5.0 ohms for both measurements?YesGo To 7NoRepair the excessive resistance in the (V937) S/C Return circuit.Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)7. S/C SWITCH SIGNAL CIRCUITS SHORTED TO THE (V937) S/C RETURN CIRCUIT

Measure the resistance between the (V937) S/C Return circuit and both of the (V71) and (V72) S/C Signal circuits in the S/C Switch harness connector.Is the resistance below 5.0 ohms?YesRepair the short between the (V937) S/C Return circuit and the (V71) or (V72) S/C Switch Signal circuit.Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)NoGo To 88. (V71) S/C SIGNAL 1 CIRCUIT SHORTED TO THE (V72) S/C SIGNAL 2 CIRCUIT

Measure the resistance between the (V71) S/C Signal 1 circuit and the (V72) S/C Signal 2 circuit at the Speed Control harness connector.Is the resistance below 100 ohms for each circuit?YesRepair the short between the (V72) S/C Signal 2 circuit and the (V71) S/C Signal 1 circuit.Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)NoGo To 99. S/C SWITCH SIGNAL CIRCUITS SHORTED TO GROUND

Measure the resistance between ground and the (V71) and (V72) S/C Switch Signal circuits at both S/C Switch harness connectors.Is the resistance below 100 ohms?YesRepair the short to ground in the (V71) or (V72) S/C Signal circuit.Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)NoGo To 1010. SPEED CONTROL SWITCH VOLTAGE VALUESAllow the engine to idle.With a scan tool, monitor the S/C Switch voltage readings.SWITCH POSITIONSWITCH No.1 VOLTAGE VALUESWITCH No.2 VOLTAGE VALUENO SWITCHES PRESSED 4.31 to 4.78 volts4.31 to 4.78 voltsON/OFF PRESSED0.59 to 1.13 volts3.53 to 3.92 voltsRES/ACCEL PRESSED3.88 to 4.17 volts2.04 to 2.47 voltsSET PRESSED3.16 to 3.56 volts1.17 to 1.56 voltsCOAST PRESSED2.57 to 2.94 volts0.77 to 1.09 voltsCANCEL PRESSED1.59 to 1.99 volts2.84 to 3.25 voltsTake these same voltage measurements with a voltmeter by back probing the (V71) S/C Signal 1 circuit and the (V72) S/C Signal 2 circuit at the switch.Compare the voltage readings on the voltmeter to what the scan tool displayed.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?YesReplace the Speed Control Switch.Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)NoGo To 1111. PCMBefore 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?YesRepair as necessary.Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)NoReplace and program the Powertrain Control Module per Service Information.Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)