Diagnostic Aids

A skewed MAP signal or faulty MAP sensor or an incorrect MAP signal may cause PCM to incorrectly calculate the predicted TP sensor value during high engine load situations. Check for an unusually low MAP reading. This condition can cause DTC to set.

Check for poor connections at PCM. Inspect harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, and poor terminal-to-wire connection.

If DTC cannot be duplicated, the information included in the FAILURE RECORDS data can be useful in determining vehicle mileage since DTC was last set. If it is determined that DTC is intermittent, performing DTC P1121 or P1122 diagnosis may isolate cause of fault.