Speedometer Inoperative

Use this fault-tracing procedure if other instrument panel gauges are working.

Sources of Fault:





- Sensor faulty.
- Open-circuit in signal lead.
- Signal lead short-circuited to ground.
- Signal lead short-circuited to supply.
- Open-circuit in ground lead.

Start fault-tracing at step 1, below.

1) Checking Speedometer:





- Ignition off.
- Undo speedometer connector by gearbox.
- Connect an ohmmeter across speedometer connector terminals 1 and 2.
- Ohmmeter should read 1820 ± 180 ohm at room temperature.

If reading is correct, check ground lead. See step 2, below.
If reading is incorrect there is a fault in the VSS. Replace VSS.

2) Checking Ground Lead:





- Ignition off.
- Connect an ohmmeter between cable harness connector terminal 2 by the VSS and ground.
- Ohmmeter should read approx. 0 ohm.

If reading is correct, go to step 3, below.

If reading is incorrect, there is an open-circuit in ground lead between VSS connector terminal 2 and instrument panel # A2. Check ground lead and connections for open-circuit. Checking Cables and Terminals

3) Checking Sensor Signal Lead:





- Ignition off.
- Connect VSS connector.
- Expose instrument panel. (Remove Dash Board Cover) Service and Repair
- Undo instrument panel connector.
- Remove instrument panel. Service and Repair
- Connect test box to cable harness connector and check ground points. Connecting Test Box
- Connect an ohmmeter across test box terminals # A2 and # A3.
- Ohmmeter should read 1820 ± 180 ohm.

If reading is correct, check the VSS signal. See step 4, below.

If reading is incorrect, there is an open-circuit or poor contact in the signal lead between VSS connector terminal 1 and instrument panel # A3. Check signal lead and connections for open-circuit, contact resistance and oxidization. Checking Cables and Terminals

4) Checking VSS Signal:

WARNING: Use axle stands if the front end of the car is raised with a car jack in order to drive with freely rotating wheels. Ensure that the handbrake is securely engaged. Before starting: Ensure that no personnel are by the front wheels when they are rotating.





- Put gearshift into neutral.
- Raise up front of car so front wheels are free to rotate.
- Ignition on.
- Connect a voltmeter set to AC across test box terminals # 3 (# A3) and # 2 (# A2). Read voltmeter while turning wheel by hand.
- Voltmeter should jump.

If voltmeter jumps, the fault is in the speedometer. Replace speedometer and test. Service and Repair (Individual Component Replacement)

If voltmeter does not jump, the fault is in the Vehicle Speed Sensor. Replace the VSS and test.