Diagnostic Aids

If a TP sensor No. 1 or No. 2 DTC is set, diagnose that DTCs first. See DIAGNOSTIC TROUBLE CODE DEFINITIONS  .

If DTC P1523 is set, the ECM will default to one of the two limp home modes (random injector disable with engine speed limited to 1800 RPM). The REDUCED POWER telltale will be illuminated and the ECM will remain in this condition for the entire ignition cycle even if the fault is corrected.

The Throttle Body Relearn Procedure should be performed anytime a throttle body has been replaced or an ECM has been replaced or reprogrammed. See THROTTLE BODY RELEARN PROCEDURE  under PROGRAMMING.