Speedometer &/Or Odometer Inoperative Or Inaccurate

Ensure vehicle has been checked for Diagnostic Trouble Codes (DTCs). See TESTS W/CODES article in ENGINE PERFORMANCE section. Connect scan tool to DLC connector. Test drive vehicle and compare scan tool speed display to instrument cluster speed display. If both speeds agree, check for correct tire size, Powertrain Control Module (PCM) calibration and VSS. If both speeds do not agree, go to next step.
If one or more of speed related features are inoperative, go to next step. If all speed related features are operating, check and repair open, short to ground or high resistance in Dark Green wire between instrument cluster Black connector terminal "N" and PCM Blue connector terminal No. 13. See Figure and Figure .
Disconnect any inoperative speed related components. Using DVOM, measure voltage between inoperative component Dark Green wire and ground. Turn ignition on. If voltage is 5-12 volts, go to next step. If voltage is not 5-12 volts, check and repair open, short to ground or battery or high resistance in Dark Green wire.
With DVOM still connected, slowly rotate drive wheel in forward rotation. If voltage does not vary from less than one volt to more than 2.5 volts, go to next step. If voltage varies from less than one volt to more than 2.5 volts, check and repair poor connection. If connection is okay, replace inoperative component.
Turn ignition off. Reconnect all speed related components. Disconnect PCM Blue connector. Turn ignition on. Measure voltage between PCM Blue connector terminal No. 13 (Dark Green wire) and ground. If voltage is more than 5 volts and less than battery voltage, check and repair connection at PCM connector. If connection is okay, replace PCM. If voltage is not more than 5 volts and less than battery voltage, check and repair open, short to ground or battery or high resistance in Dark Green wire.