Diagnostic Procedure Buick Century VI

Diagnostic Procedure

1. Turn ignition ON, engine OFF. Does the scan tool turn ON? If so, go to next step. If not, diagnose scan tool concern. See appropriate BODY CONTROL MODULES article in ACCESSORIES & EQUIPMENT. NOTE: Check for applicable service bulletins before proceeding with this diagnostic procedure. Perform this diagnostic procedure only if there is a driveability complaint or if you have been directed to this diagnostic procedure from another section in the service information. NOTE: Do not turn the ignition OFF when performing this diagnostic procedure. Do not clear the DTCs unless instructed by this diagnostic procedure.
2. Is the MIL ON? If so, go to next step. If not, diagnose MIL concern. See appropriate SELF-DIAGNOSTICS article in ENGINE PERFORMANCE.
3. Attempt to establish communication with the PCM. Does the scan tool communicate with the PCM? If so, go to next step. If not, diagnose scan tool concern. See appropriate BODY CONTROL MODULES article in ACCESSORIES & EQUIPMENT.
4. Use the scan tool CAPTURE INFO function to save or capture (store information) any DTC information. Are there any DTCs present? If so, see «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(/buick/century/vi-1997-2005/remont/automatic-trans/#automatic-transaxle-diagnosis-4t65-e__diagnostic-trouble-code-definitions) . If not, see «SYMPTOM DIAGNOSIS»(/buick/century/vi-1997-2005/remont/automatic-trans/#automatic-transaxle-diagnosis-4t65-e__symptom-diagnosis) under TROUBLE SHOOTING. NOTE: DTCs, engine performance, and transaxle default actions can greatly affect the transaxle performance. Ensure that these items are not the cause of a transaxle concern.