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.
Check Mode Procedure
HINT: Hand-held tester only:
Check mode has a higher sensitivity to detect malfunctions and can detect malfunctions that normal mode cannot detect.
Check mode can also detect all the malfunctions that normal mode can detect.
- CHECK MODE PROCEDURE (Using the hand-held tester)
- Make sure that the items below are true.
- Battery positive voltage 11 V or more
- Throttle valve fully closed
- Transmission in the P or N position
- A/C switched OFF
- Turn the ignition switch to OFF.
- Connect the hand-held tester to the DLC3.
- Turn the ignition switch to ON.
- Change the ECM to check mode with the hand-held tester. Make sure the MIL flashes as shown in the illustration.
- Make sure that the items below are true.
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
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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.
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