Operation CHARM: Car repair manuals for everyone.

Speed Signal, Checking







Speed Signal, Checking

Observe all safety precautions: => [ Safety Precautions ] Safety Precautions

View clean working conditions: => [ Clean Working Conditions ] Clean Working Conditions

Prior to repair work, perform a preliminary check to verify the condition. Refer to => [ Preliminary Check ] Preliminary Check.

Use only gold-plated terminals when servicing any component with gold-plated electrical harness connector terminals.

For wiring diagrams, component locations, and connector views, Refer to the applicable wiring diagram.

Special tools, testers and auxiliary items required

Scan tool.

Wiring diagram.

Test requirements

The Speedometer (G21) OK.

The Engine Control Module (ECM) (J623) and ABS module fuses OK.

Battery voltage at least 12.5 volts.

All electrical consumers such as, lights and rear window defroster, switched off.

A/C switched off.

Ground connections between engine/transmission/chassis OK.

Ignition switched off.

Function test

- Connect the scan tool.

- Perform a road test with a vehicle speed greater than 5 Km/h.

- Using the scan tool to access the ABS module, check the vehicle speed displayed:






- Compare the vehicle speed on the scan tool to the Speedometer (G21).

Specified value: a difference of no greater than 10%.

If the specified value was not obtained or no speed was displayed on the cluster:

- Check the electrical harness connector at the Instrument Cluster Control Module (J285) for an open circuit, Short to Battery (+), or to Ground. Refer to Wiring Diagram.

- Check the wiring connection for damage, corrosion, loose or broken terminals.

- If necessary, repair the faulty wiring connection.

If the wiring check is OK:

- Replace the Instrument Cluster. Refer to the Repair Information.

Final procedures

After the repair work, the following work steps must be performed in the following sequence:

1. Check the DTC memory. Refer to => [ Diagnostic Mode 03 - Read DTC Memory ] Diagnostic Modes 01 - 09.

2. If necessary, erase the DTC memory. Refer to => [ Diagnostic Mode 04 - Erase DTC Memory ] Diagnostic Modes 01 - 09.

3. If the DTC memory was erased, generate readiness code. Refer to => [ Readiness Code ] Monitors, Trips, Drive Cycles and Readiness Codes.