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.
Circuit Description
The ECM continuously monitors it's internal memory status, internal circuits, and output signals to the throttle actuator. This self-check determines whether the ECM is functioning properly. If any malfunction is detected, the ECM will set the appropriate DTC and illuminate the MIL.
The ECM memory status is diagnosed by internal "mirroring" of the main CPU and the sub CPU to detect random access memory (RAM) errors. The two CPUs also perform continuous mutual monitoring. If there is a difference between outputs from the two CPUs that deviates from standard level ranges, the ECM concludes that there is a fault and sets a DTC. Additionally, if the signals to the throttle actuator deviate from the standard range or if the ECM detects malfunction in the throttle actuator supply voltage, the ECM will conclude that there is a fault and set a DTC. With any malfunction of the ECM, the MIL will be turned on and DTC (s) will be set.
| DTC No. | DTC Detection Condition | Trouble Area |
|---|---|---|
| P0606 | ECM inside error | ECM |
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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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