Diagnostic Tests: Notes
WARNING:
While ignition is on, DO NOT connect or disconnect battery, or any other electrical connector. Component damage may result.
CAUTION:
When battery is disconnected, vehicle computer memory system may lose memory data. Driveability problems may exist. After disconnecting battery or replacing ECM, drive vehicle to enable ECM to relearn driveability. Inform your customer that they may experience driveability different from what they are accustomed to until ECM completes relearn function.
CAUTION:
DO NOT spray carburetor cleaner on or near coils or plug wires. Allow enough time between checking areas for leaks for carburetor spray to dissipate.
NOTE:
Before performing any DIAGNOSTIC TEST, refer to SELF-DIAGNOSTIC SYSTEM
for system functions and system diagnostic procedures.
NOTE:
If more than one DTC is stored at ECM memory, always perform diagnosis from first DTC stored at ECM memory, unless stated otherwise in test procedure.
NOTE:
If component testing procedure is not covered in this article, see SYSTEM & COMPONENT TESTING
article.
NOTE:
For identification of circuits, terminals and wire colors referenced in the testing procedure. See WIRING DIAGRAMS
article.
NOTE:
After any repair has been made, see AFTER-REPAIR PROCEDURE
under SELF DIAGNOSTIC SYSTEM.
NOTE:
For component removal and installation. See REMOVAL, OVERHAUL & INSTALLATION
article.
NOTE:
In some instances, a short to ground or a short to power may cause damage to control modules. Do not replace control modules until testing proves these conditions do not exist. Also verify that ground circuits have good continuity to ground.