FREE REPAIR MANUALS & LABOR GUIDES 1982-2013 Vehicles
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Test Z: The O/D Off Indicator Is Never/Always On

PINPOINT TEST Z: THE O/D OFF INDICATOR IS NEVER/ALWAYS ON

Normal Operation
The instrument cluster receives the overdrive (O/D) off signal from the PCM over the high speed controller area network (HS-CAN) communication bus. When the O/D function is selected off, the PCM sends a message to the instrument cluster to illuminate the O/D off indicator. If the O/D on/off message is missing or if the data is deemed invalid by the instrument cluster for more than 5 seconds, the instrument cluster sets DTC U0100 in continuous memory and defaults the O/D off indicator off.

NOTE: If DTC U0100 is set in the instrument cluster, other observable symptoms may be an inoperative speedometer, tachometer or odometer.

This pinpoint test is intended to diagnose the following:
- O/D concern
- PCM
- Instrument cluster


Z1-Z5:






Z6: