Speedometer Inoperative

Conditions:





- Other gauges on instrument panel 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.

1) Checking Speedometer:





- Ignition off.
- Undo speedometer connector on gearbox as per Vehicle Speed Sensor Replacement Procedure.
- Connect an ohmmeter across speedometer connector terminals 1 and 2.
- Ohmmeter should read 1820 ± 180 ohms at room temperature.

If reading is correct:
- Check ground lead, see step 2 below.

If reading is incorrect:
- Fault in Speedometer. Replace Speedometer and test.

2) Checking Ground Lead:





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

If reading is correct:
- Check sensor signal lead. See step 3, below.

If reading is incorrect:
- Open-circuit in ground lead between speedometer connector terminal 2 and # A2 on instrument panel.
Check ground lead and connections for open-circuit. Checking Cables and Terminals

3) Checking Signal Lead:





- Ignition off.
- Connect speedometer connector.
- Expose instrument panel (Remove Dash 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 (Breakout) Box





- Connect an ohmmeter across test box terminals # A2 and # A3.
- Ohmmeter should read 1820 ± 180 ohms.

If reading is correct:
- Check VSS signal, step 4 below.

If reading is incorrect:
- Open-circuit or poor contact in signal lead between speedometer connector terminal 1 and # A3 on instrument panel.
- Check signal lead and connections for open-circuit and contact resistance and oxidization. Checking Cables and Terminals

4) Checking VSS Signal:





- Put gearshift in neutral.
- Jack up front of car so front wheels are tree to turn.
- Ignition on.
- Connect a voltmeter set to AC across # 3 (# A3) and # 2 (# A2) on test box, read voltmeter reading while turning wheel by hand.
- Voltmeter should jump.

If voltmeter jumps:
- Fault in speedometer. Replace speedometer. (Individual Component Replacement) Service and Repair

If voltmeter does not jump:
- Fault in speedometer sensor (VSS). Replace VSS and test.