• HEADINGS
  • * PLEASE READ THIS FIRST *
  • WHERE DOES DRIVEABILITY DIAGNOSIS START?
    • PERFORM BASIC INSPECTION
    • CHECK FOR TROUBLE CODES
    • DIAGNOSE SYMPTOM
    • TEST SYSTEM
• FIGURES
• TABLES

GENERAL INFORMATION

Engine Performance Diagnostic Routine Outline

* PLEASE READ THIS FIRST *

NOTE:

This article is generic in nature and all information does not apply to all vehicles. For vehicle specific information, see the appropriate articles in the ENGINE PERFORMANCE category.

WHERE DOES DRIVEABILITY DIAGNOSIS START?

PERFORM BASIC INSPECTION

NOTE:

This article is generic in nature and all information does not apply to all vehicles. For vehicle specific information, see the appropriate articles in the ENGINE PERFORMANCE category.

1. Verify Customer Complaint
2. Check for Relevant Technical Service Bulletins (TSBs)
3. Perform Visual Inspection (See Basic Diagnostic Procedures)
4. Test Engine Sub-Systems (See Basic Diagnostic Procedures)
   • Mechanical Condition (Compression)
   • Ignition Output
   • Fuel Delivery
5. Check Air Induction System For Leaks
6. Check & Adjust Basic Engine Settings(See On-Vehicle Adjustments)
   • Ignition Timing
   • Idle Speed

CHECK FOR TROUBLE CODES

NOTE:

This article is generic in nature and all information does not apply to all vehicles. For vehicle specific information, see the appropriate articles in the ENGINE PERFORMANCE category.

1. Check for Diagnostic Trouble Codes (DTCs).(See Self-Diagnostics)
2. Repair cause of DTCs.
3. Clear PCM memory and repeat self-test.

DIAGNOSE SYMPTOM

NOTE:

This article is generic in nature and all information does not apply to all vehicles. For vehicle specific information, see the appropriate articles in the ENGINE PERFORMANCE category.

1. If no self-diagnostics available, or no trouble codes present, identify symptom.
2. See trouble shooting procedure to identify problem. (See Trouble Shooting - No Codes)

TEST SYSTEM

NOTE:

This article is generic in nature and all information does not apply to all vehicles. For vehicle specific information, see the appropriate articles in the ENGINE PERFORMANCE category.

1. Perform required tests. (See Systems & Component Testing)
2. Verify complaint is repaired.