Diagnostic Aids
WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2004 Oldsmobile Bravada, 2004 GMC Envoy XUV, 2004 GMC Envoy XL, 2004 GMC Envoy, and 2004 Chevrolet TrailBlazer. However, it is still accessible from the selected car via links, so may be relevant.
Attempting to start the vehicle by bypassing the Passlock system or by substituting parts without performing the Programming Theft Deterrent System Components procedure may set a DTC P1631 and a P1632.
If no password is received, a DTC U1064 and P1632 may be set.
An intermittent may be caused by a poor connection, a rubbed through wire insulation, or by a wire broken inside the insulation.
Thoroughly check any suspected circuitry for the following items:
- Backed out terminals or improper mating
- Broken locks
- Improperly formed or damaged terminals
- Poor terminal to wiring connections
- Physical damage to the wiring harness
- Corrosion