Diagnostic Aids

An intermittent problem can be caused by misrouted harness, rubbed-through wire insulation or broken wire inside insulation. Check for poor connection at PCM. Inspect harness connectors for backed-out terminals, improper mating, broken locks, improperly formed or damaged terminals and poor terminal connection. Inspect wiring harness for damage. If harness appears to be okay, use scan tool to observe sensor readings while moving connectors and harnesses. A change in display will indicate location of fault.

Low MAP reading can cause PCM to incorrectly calculate TP sensor value. If DTC cannot be duplicated, check scan tool FAILURE RECORDS to determine mileage since last DTC was set. If it is determined that DTC is intermittent, performing DTCs P1121 and DTC P1122 diagnostics may isolate cause of fault.