For 1990-2009 cars

### Diagnostic Instructions

• | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

• | Review Strategy Based Diagnosis for an overview of the diagnostic approach.

• | Diagnostic Procedure Instructions provide an overview of each diagnostic category.

### DTC Descriptor

DTC P0500: Vehicle Speed Sensor (VSS) Circuit

### Circuit/System Description

The transmission control module (TCM) provides the engine control module (ECM) vehicle speed information through the high-speed communications on the controller area network (CAN). Vehicle speed is produced by the AC current generated through the transmission output shaft speed (OSS) sensor as the output shaft rotates. The ECM continuously monitors the vehicle speed signal supplied by the TCM.

### Conditions for Running the DTC

• | DTCs P0689 and P0690 are not set.

• | The engine is running.

• | The ignition 1 voltage is between 10-16 volts.

• | The DTC runs continuously once the above conditions are met.

### Conditions for Setting the DTC

The ECM detects that the vehicle speed is greater than 270 km/h (167 mph) or less than 10 km/h (3 mph) for a calibrated length of time.

### Action Taken When the DTC Sets

DTC P0500 is a Type B DTC.

### Conditions for Clearing the DTC

DTC P0500 is a Type B DTC.

### Reference Information

#### Schematic Reference

Engine Controls Schematics

#### Connector End View Reference

• | Engine Control Module Connector End Views

• | Engine Controls Connector End Views

#### Electrical Information Reference

• | Circuit Testing

• | Connector Repairs

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

#### DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

#### Scan Tool Reference

• | Scan Tool Data List

• | Scan Tool Data Definitions

• | Scan Tool Output Controls

### Circuit/System Verification

1. Raise the drive wheels.

Notice: Support the lower control arms in the normal horizontal position in order to avoid damage to the drive axles. Do not operate the vehicle in gear with the wheels hanging down at full travel.

2. Support the lower control arms so that the drive axles are in a horizontal position.
3. Start and idle the engine.
4. Engage the transmission into 2nd gear.
5. Observe the scan tool VSS parameter. The following should display a vehicle speed once the drive wheels are at a speed above 8 km/h (5 mph):

• | The VSS parameter

• | The speedometer

6. If the vehicle passes the Circuit/System Verification test, then operate the vehicle within the conditions for running the DTC. You may also operate the vehicle within the conditions that are captured in the Freeze Frame/Failure Records Data List.

### Circuit/System Testing

1. Ignition ON, verify there are no TCM DTCs set.

⇒ | If TCM DTCs are set refer to Diagnostic Trouble Code (DTC) List - Vehicle for further diagnosis.

2. Ignition OFF, test the CAN communication circuits between the ECM and the TCM for an open, short to ground, or a short to voltage.
3. If all circuits test normal, replace the ECM.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for engine control module replacement, setup, and programming