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.
Fail-Safe Function
When a malfunction has occurred in specific areas of engine and emission control system, ECM enters "fail-safe function". When vehicle is operating in fail-safe function, ECM allows a lower level of engine performance to be available, allowing vehicle to be driven for service. When malfunction occurs a failure signal is sent to ECM, and ECM control over affected sensors and actuators is maintained on the basis of standard signals and/or a back-up program stored in ECM. While in fail-safe mode ECM ignores failure signal and/or CPU inputs. ECM will remain in fail-safe mode as long as malfunction is detected, fail-safe mode is canceled when ECM detects normal conditions. For fail-safe function parameters and detected item. See Fig 1.
Use the Manual With the Right Hardware
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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.