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.
DTC C1605: CAN Hardware Error: General Description
The HECU sends requirement data, such as torque reduction, the number of fuel cut cylinders, and the ESC (ESP) control request, to the PCM (ECM & TCM) through CAN bus line. The PCM (ECM) performs the fuel cut function according to a request signal from the HECU and then retards an ignition timing. The PCM (TCM) maintains current gear position during the ESC (ESP) control period in order not to increase power which causes a Kickdown shift.
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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.