Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Testing Procedure
To ensure correct diagnosis and repair, testing should be done in the following sequence:
- Get information about conditions present when malfunction occurred. Retrieve and record DTCs and freeze-frame data. If MIL is on, and DTCs are not accessible, check for ECM fail-safe mode. See FAIL-SAFE MODES . If symptoms exist, but DTCs or freeze-frame data do not exist, go to next step. If symptoms do not exist, but DTCs or freeze-frame data exist, go to step 3.
- Attempt to duplicate conditions present when malfunction occurred. If malfunction is detected, perform basic inspection. See BASIC INSPECTION under THROTTLE POSITION SWITCH, IGNITION TIMING & IDLE SPEED in ON-VEHICLE ADJUSTMENTS article. Then go to TROUBLE SHOOTING - NO CODES article for diagnosis by symptom. If malfunction can not be verified, problem may be intermittent. See INTERMITTENT SIMULATION TESTS .
- Clear DTCs and freeze-frame data. Attempt to reset DTC by performing DTC CONFIRMATION TEST in appropriate diagnostic test. If multiple DTCs are present, diagnose in order of priority. See appropriate MULTIPLE DTC PRIORITY IDENTIFICATION table. See appropriate SELF-DIAGNOSTICS article. If DTC does not reset, problem may be intermittent. See INTERMITTENT SIMULATION TESTS . If DTC resets, go to next step.
- Perform appropriate diagnostic procedure. See appropriate SELF-DIAGNOSTICS article. After repairs are made, perform appropriate DTC CONFIRMATION TEST to verify repair. Clear DTCs. If SRT codes are not set, drive vehicle in specified driving pattern to set all SRT codes. See SYSTEM READINESS TEST (SRT) under ADDITIONAL SYSTEM FEATURES.
| Priority | DTC | ||
|---|---|---|---|
| 1 | P0100, P0110, P0115, P0120, P0125, P0180, P0325, P0335, P0340, P0403, P0460, P0461, P0464, P0500, P0600, P0605, P1126, P1220, P1320, P1335, P1336, P1400, P1464, P1605 & P1706 | ||
| 2 | P0105, P0130, P0131, P0132, P0133, P0134, P0135, P0137, P0138, P0139, P0140, P0141, P0150, P0151, P0152, P0153, P0154, P0155, P0443, P0446, P0450, P0510, P0705, P0710, P0720, P0725, P0740, P0744, P0745, P0750, P0755, P1105, P1165, P1401, P1444, P1446, P1447, P1448, P1490, P1491, P1705 & P1760 | ||
| 3 | P0171, P0172, P0174, P0175, P0300, P0301, P0302, P0303, P0304, P0305, P0306, P0400, P0402, P0420, P0430, P0440, P0455, P0505, P0600, P0731, P0732, P0733, P0734, P1110, P1130, P1131, P1148, P1168, P1402, P1440 & P1441 | ||
|
|||
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Disclosure: Verified tool recommendations may earn an affiliate commission at no cost to you.
When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.
Rather have a pro handle this?
A certified mobile mechanic comes to your home or office. They bring the tools, you stay comfortable. No tow truck, no waiting room, no surprises.
No obligation. See pricing before you book.