Speedometer Head: Testing and Inspection

If the problem being diagnosed is related to speedometer accuracy, be certain to confirm that the problem is with the speedometer gauge and not with an incorrect pinion factor, axle ratio, or tire size.

WARNING: ON VEHICLES EQUIPPED WITH AIRBAGS, REFER TO AIRBAGS BEFORE ATTEMPTING ANY STEERING WHEEL, STEERING COLUMN, OR INSTRUMENT PANEL COMPONENT DIAGNOSIS OR SERVICE. FAILURE TO TAKE THE PROPER PRECAUTIONS COULD RESULT IN ACCIDENTAL AIRBAG DEPLOYMENT AND POSSIBLE PERSONAL INJURY.

Diagnosis of the rear wheel speed sensor and circuit, the CAB, the Chrysler Collision Detection (CCD) data bus, and/or the Powertrain Control Module (PCM) should be performed with a DRB scan tool. For further diagnosis of the speedometer and the instrument cluster circuitry, refer to Instrument Panel/Testing and Inspection. Testing and Inspection.