Diagnostic Test

Ignition on, engine not running.

Ask the customer if it is possible that two buttons were pressed at the same time before this DTC set. If this is the case, no repair is necessary.

Is the DTC active a this time? 

Yes 

1. Go To step  2).

No 

1. Refer to INTERMITTENT CONDITION .
2. Perform POWERTRAIN VERIFICATION TEST .

With the scan tool, monitor the Speed Control Switch voltage.

Disconnect the Speed Control On/Off Switch harness connector.

Did the voltage change to above 4.8 volts? 

Yes 

1. Replace the Speed Control On/Off Switch.
2. Perform POWERTRAIN VERIFICATION TEST .

No 

1. Go To step  3).

With the scan tool, monitor the Speed Control Switch voltage.

Disconnect the Speed Control Resume/Accel Switch harness connector.

Did the voltage change to above 4.8 volts? 

Yes 

1. Replace the Speed Control Resume/Accel Switch.
2. Perform POWERTRAIN VERIFICATION TEST .

No 

1. Go To step  4).

Turn the ignition off.

Remove and disconnect the Speed Control Switches 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 (V372) S/C Switch No.2 Signal and (V397) S/C Switch Return circuits of the Switch when holding the switch button in the following position.

Not pressing any switch - 20.5 kohms

On/Off - 8.87 kohms

Set - 0.825 kohms

Coast - 0.47 kohms

Cancel - 3.92 kohms

Resume/Accel - 1.87 kohms

The following resistance specs are taken between terminals (V371) S/C Switch No.1 Signal and (V397) S/C Switch Return circuits of the Switch when holding the switch button in the following position

Not pressing any switch - 20.5 kohms

On/Off - 0.47 kohms

Set - 5.49 kohms

Coast - 2.94 kohms

Cancel - 1.24 kohms

Resume/Accel - 15.4 kohms

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

Yes 

1. Go To step  5).

No 

1. Replace the Speed Control Switch that had the incorrect resistance value.
2. Perform POWERTRAIN VERIFICATION TEST .

Fig 1: Checking Speed Control Switch No. 1 Signal Circuit

Courtesy of DAIMLERCHRYSLER CORP.

Disconnect the C3 PCM harness connector.

Measure the voltage on the (V371/V71) S/C Switch Signal circuit at both Speed Control harness connectors.

Is the voltage above 5.0 volts? 

Yes 

1. Repair the short to battery voltage in the (V371/V71) S/C Switch Signal circuit.
2. Perform POWERTRAIN VERIFICATION TEST .

No 

1. Go To step  6).

Turn the ignition off.

Disconnect the C1 and C3 SCCM harness connectors per Service Information.

Measure the resistance of the (V371/V71) S/C Switch Signal circuit between the C1 and C3 SCCM connections.

Measure the resistance of the (V397/V937) Switch Return circuit between the C1 and C3 SCCM connections.

Is the resistance above 5.0 ohms? 

Yes 

1. Replace the SCCM per Service Information.
2. Perform POWERTRAIN VERIFICATION TEST .

No 

1. Go To step  7).

Fig 2: Checking Speed Control Switch No. 1 Signal Circuit

Courtesy of DAIMLERCHRYSLER CORP.

Measure the resistance of the (V371/V71) S/C Switch No.1 Signal circuits from both Speed Control harness connectors to the appropriate terminals of special tool #8815.

Is the resistance below 5.0 ohms for each measurement? 

Yes 

1. Go To step  8).

No 

1. Repair the excessive resistance in the (V371/V71) S/C Switch No.1 Signal circuit.
2. Perform POWERTRAIN VERIFICATION TEST .

Fig 3: Checking Speed Control Switch Return Circuit

Courtesy of DAIMLERCHRYSLER CORP.

Measure the resistance of the (V397/V937) Switch Return circuit from both Speed Control harness connector to the appropriate terminal of special tool #8815.

Is the resistance below 5.0 ohms for both measurements? 

Yes 

1. Go To step  9).

No 

1. Repair the excessive resistance in the (V397/V937) Switch Return circuit.
2. Perform POWERTRAIN VERIFICATION TEST .

Fig 4: Checking Speed Control Switch No. 1 Signal Circuit & Return Circuit

Courtesy of DAIMLERCHRYSLER CORP.

Measure the resistance between the (V397/V937) Switch Return circuits and the (V371/V71)S/C Switch No.1 Signal circuits in the S/C Switch harness connector.

Is the resistance below 5.0 ohms? 

Yes 

1. Repair the short between the (V397/V937) Switch Return circuit and the (V371/V71) S/C Switch No.1 Signal circuit.
2. Perform POWERTRAIN VERIFICATION TEST .

No 

1. Go To step  10).

Fig 5: Checking Speed Control Switch No. 1 Signal Circuit

Courtesy of DAIMLERCHRYSLER CORP.

Measure the resistance between ground and the (V371/V71) S/C Switch No.1 Signal circuit at both Switch harness connectors.

Is the resistance below 100 ohms? 

Yes 

1. Repair the short to ground in the (V371/V71) S/C Switch No.1 Signal circuit.
2. Perform POWERTRAIN VERIFICATION TEST .

No 

1. Go To step  11).

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 (V371) S/C Switch No.1 Signal circuit at the switches.

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? 

Yes 

1. Replace the Speed Control Switch.
2. Perform POWERTRAIN VERIFICATION TEST .

No 

1. Go To step  12).

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? 

Yes 

1. Repair as necessary.
2. Perform POWERTRAIN VERIFICATION TEST .

No 

1. Replace and program the Powertrain Control Module per Service Information.
2. Perform POWERTRAIN VERIFICATION TEST .