Diagnostic Tests: Notes

CAUTION: If engine control module (ECM) replacement is instructed in following tests, always ensure ECM connectors and ground circuits are okay. If either are defective, repair and repeat testing to confirm ECM malfunction.

NOTE: Before performing any diagnostic test, see SELF-DIAGNOSTIC SYSTEM for diagnostic system functions and system diagnostic procedures. Also check for any related Technical Service Bulletins (TSBs). For component location, see appropriate illustration in THEORY & OPERATION article.

NOTE: When performing diagnostic tests, it may be necessary to identify ECM harness connector terminals referenced in testing. See Fig 1.

Fig 1: Identifying Engine Control Module Connector Terminals