Testing Procedure

To ensure correct diagnosis and repair, testing should be done in the following sequence:

• Record Customer Complaint
  
  Ensure all customer complaints or observations are recorded.
• Retrieve Diagnostic Trouble Codes
  
  Retrieve Diagnostic Trouble Codes (DTC) from Engine Control Module (ECM). See RETRIEVING DIAGNOSTIC TROUBLE CODES .
• Clear Diagnostic Trouble Codes
  
  Clear DTCs from ECM. See CLEARING DIAGNOSTIC TROUBLE CODES .
• Confirm Symptoms & Diagnostic Trouble Codes
  
  Determine if original symptoms still exist. Retrieve DTCs from ECM. See RETRIEVING DIAGNOSTIC TROUBLE CODES .
• Diagnose & Repair Diagnostic Trouble Codes
  
  For DTC description, see ENGINE IMMOBILIZER DIAGNOSTIC TROUBLE CODE DEFINITIONS  table. Perform appropriate DTC test listed under DIAGNOSTIC TESTS  as necessary. If no DTCs are present, trouble shoot engine immobilizer system by symptom. See TROUBLE SHOOTING .
• Verification Procedure
  
  After repairs have been completed, clear all DTCs from ECM. See CLEARING DIAGNOSTIC TROUBLE CODES . Ensure no DTCs exist and all symptoms and/or complaints have been repaired.