Diagnostic Test

WARNING: This page is about a different car, the 2005 Jeep Grand Cherokee. However, it is still accessible from the selected car via links, so may be relevant.

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.

Is the Speed Control voltage below 1.0 volt?

Yes
1. Go To step 2).
No
1. Refer to INTERMITTENT CONDITION .
2. Perform POWERTRAIN VERIFICATION TEST .
2) SPEED CONTROL SWITCHES
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 (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 positions.

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 3).
No
1. Replace the Speed Control Switch that had the incorrect resistance value.
2. Perform POWERTRAIN VERIFICATION TEST .
3) SPEED CONTROL ON/OFF SWITCH
Connect the Resume/Accel Switch.

Ignition on, engine not running.

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 4).
4) SPEED CONTROL RESUME/ACCEL SWITCH
With the scan tool, monitor the Speed Control Switch voltage.

Disconnect the Speed Control Resume/Accel Switch harness connector per Service Information.

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 5).
5) STEERING COLUMN CONTROL MODULE
Turn the ignition off.

Disconnect the C1 SCCM harness connector per Service Information.

Ignition on, engine not running.

With the scan tool, read the S/C Switch voltage.

Did the S/C Switch volts change to 5.0 volts?

Yes
1. Replace the Clockspring.
2. Perform POWERTRAIN VERIFICATION TEST .
No
1. Go To step 6).
6) (V371) S/C SWITCH NO.1 SIGNAL CIRCUIT SHORTED TO THE (V397) S/C SWITCH RETURN CIRCUIT

Fig 1: Checking Speed Control Switch No. 1 Signal Circuit & Return Circuit
Courtesy of DAIMLERCHRYSLER CORP.

Turn the ignition off.

Disconnect the C3 SCCM harness connector.

Disconnect the C3 PCM harness connector.

Measure the resistance between the (V397) S/C Switch Return circuit and the (V371) S/C Switch No.1 Signal circuit at the S/C Switch harness connectors.

Is the resistance below 5.0 ohms?

Yes
1. Repair the short between the (V371) S/C Switch No.1 Signal circuit and the (V397) S/C Switch Return circuit.
2. Perform POWERTRAIN VERIFICATION TEST .
No
1. Go To step 7).
7) (V71) S/C SWITCH NO.1 SIGNAL CIRCUIT SHORTED TO THE (V937) S/C SWITCH RETURN CIRCUIT

Fig 2: Checking Speed Control Switch No. 1 Signal Circuit & Return Circuit
Courtesy of DAIMLERCHRYSLER CORP.

Measure the resistance between the (V71) S/C Switch No.1 Signal circuit and the (V937) S/C Switch Return circuit in the C1 SCCM harness connector.

Is the resistance below 5.0 ohms?

Yes
1. Repair the short between the (V71) S/C Switch No.1 Signal circuit and the (V937) Switch Return circuit.
2. Perform POWERTRAIN VERIFICATION TEST .
No
1. Go To step 8).
8) (V371) S/C SWITCH NO.1 SIGNAL CIRCUIT SHORTED TO GROUND

Fig 3: Checking Speed Control Switch No. 1 Signal Circuit
Courtesy of DAIMLERCHRYSLER CORP.

Measure the resistance between ground and the (V371) S/C Switch No.1 Signal circuit in the S/C Switch harness connector.

Is the resistance below 100 ohms?

Yes
1. Repair the short to ground in the (V371) S/C Switch No.1 Signal circuit.
2. Perform POWERTRAIN VERIFICATION TEST .
No
1. Go To step 9).
9) (V71) S/C NO.1 SWITCH SIGNAL CIRCUIT SHORTED TO GROUND

Fig 4: Checking Speed Control Switch No. 1 Signal Circuit
Courtesy of DAIMLERCHRYSLER CORP.

Measure the resistance between ground and the (V71) S/C Switch No.1 Signal circuit in the C1 SCCM harness connector.

Is the resistance below 100 ohms?

Yes
1. Repair the short to ground in the (V71) S/C Switch No.1 Signal circuit.
2. Perform POWERTRAIN VERIFICATION TEST .
No
1. Go To step 10).

10) SPEED CONTROL SWITCH VOLTAGE VALUES

Allow the engine to idle.

With a scan tool, monitor the S/C Switch voltage readings.

SWITCH POSITION	SWITCH No.1 VOLTAGE VALUE	SWITCH No.2 VOLTAGE VALUE
NO SWITCHES PRESSED	4.31 to 4.78 volts	4.31 to 4.78 volts
ON/OFF PRESSED	0.59 to 1.13 volts	3.53 to 3.92 volts
RES/ACCEL PRESSED	3.88 to 4.17 volts	2.04 to 2.47 volts
SET PRESSED	3.16 to 3.56 volts	1.17 to 1.56 volts
COAST PRESSED	2.57 to 2.94 volts	0.77 to 1.09 volts
CANCEL PRESSED	1.59 to 1.99 volts	2.84 to 3.25 volts

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 value?

Yes

Replace the Speed Control Switch.
Perform POWERTRAIN VERIFICATION TEST .

Go To step 11).

11) 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.

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 .