Diagnostic Test

1) ACTIVE DTC
Ignition on, engine not running.

With a scan tool, read DTCs.

Is the DTC active at this time?

Yes
1. Go To 2).
No
1. Refer to the INTERMITTENT CONDITION diagnostic procedure.
2. Perform the POWERTRAIN VERIFICATION TEST. (Refer to STANDARD PROCEDURE - POWERTRAIN VERIFICATION TEST) .
2) (F856) 5 VOLT SUPPLY CIRCUIT OPEN
Turn the ignition off.

Disconnect the Vehicle Speed Sensor harness connector.

Turn the ignition on.

Measure the voltage of the (F856) 5 Volt Supply circuit in the VSS harness connector.

Is the voltage above 4.6 volts?

Yes
1. Go To 3).
No
1. Repair the (F856) 5 Volt Supply circuit for an open.
2. Perform the POWERTRAIN VERIFICATION TEST. (Refer to STANDARD PROCEDURE - POWERTRAIN VERIFICATION TEST) .
3) VSS SIGNAL

Fig 1: MEASURING FOR VOLTAGE ON THE VSS SIGNAL CIRCUIT
Courtesy of DAIMLERCHRYSLER CORP.

Measure the voltage of the (K75) VSS Signal circuit in the VSS harness connector.

Is the voltage between 4.5 to 5.0 volts?

Yes
1. Go To 4).
No
1. Go To 5).
4) (K914) SENSOR GROUND CIRCUIT OPEN

Fig 2: MEASURING RESISTANCE OF THE VSS SENSOR GROUND CIRCUIT
Courtesy of DAIMLERCHRYSLER CORP.

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 No. 8815 to perform diagnosis.

Measure the resistance of the (K914) VSS Sensor Ground circuit between the VSS harness connector and to the appropriate terminal of special tool No. 8815.

Is the resistance below 5.0 ohms?

Yes
1. Remove and inspect the Pinion Gear. If OK, replace the Vehicle Speed Sensor.
2. Perform the POWERTRAIN VERIFICATION TEST. (Refer to STANDARD PROCEDURE - POWERTRAIN VERIFICATION TEST) .
No
1. Repair the (K914) Sensor ground circuit for an open.
2. Perform the POWERTRAIN VERIFICATION TEST. (Refer to STANDARD PROCEDURE - POWERTRAIN VERIFICATION TEST) .
5) (K75) VSS SIGNAL CIRCUIT SHORTED TO GROUND

Fig 3: MEASURING RESISTANCE OF THE VEHICLE SPEED SENSOR SIGNAL CIRCUIT
Courtesy of DAIMLERCHRYSLER CORP.

Disconnect the PCM harness connector.

Measure the resistance of the (K75) Vehicle Speed Sensor Signal circuit in the VSS harness connector to ground.

Is the resistance below 100 ohms?

Yes
1. Repair the (K75) VSS Signal circuit for a short to ground.
2. Perform the POWERTRAIN VERIFICATION TEST. (Refer to STANDARD PROCEDURE - POWERTRAIN VERIFICATION TEST) .
No
1. Go To 6).
6) (K75) VSS SIGNAL CIRCUIT OPEN

Fig 4: MEASURING RESISTANCE OF THE VSS SIGNAL CIRCUIT
Courtesy of DAIMLERCHRYSLER CORP.

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 No. 8815 to perform diagnosis.

Measure the resistance of the (K75) VSS Signal circuit between the VSS harness connector and to the appropriate terminal of special tool No. 8815.

Is the resistance below 5 ohms?

Yes
1. Go To 7).
No
1. Repair the (K75) VSS Signal circuit for an open.
2. Perform the POWERTRAIN VERIFICATION TEST. (Refer to STANDARD PROCEDURE - POWERTRAIN VERIFICATION TEST) .
7) PCM
NOTE: Before continuing, check the PCM harness connector terminals for corrosion, damage, or terminal push out. Repair as necessary.

If there are no possible causes remaining, view repair,

Repair
1. Replace and program the Powertrain Control Module in accordance with the Service Information. Refer to MODULE-POWERTRAIN CONTROL and STANDARD PROCEDURE - PCM/ECM/SKREEM PROGRAMMING .
2. Perform the POWERTRAIN VERIFICATION TEST. (Refer to STANDARD PROCEDURE - POWERTRAIN VERIFICATION TEST) .