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.
Diagnostic trouble code (DTC) information
Condition
Diagnostic trouble code (DTC) ECM-9100 is stored if the engine control module (ECM) registers an internal fault or a fault in the circuit for the damper motor in the throttle unit when the ignition is switched on.
Substitute Value
The engine control module (ECM) shuts down the supply to the throttle unit damper motor. The throttle will set itself to the return position.
Possible Source
- Contact resistance or oxidation in the terminals between the engine control module (ECM) and the throttle unit
- Open-circuit, short-circuit to ground or short-circuit to supply voltage in the wiring for the damper motor in the throttle unit
- Short-circuit to each other in the wiring for the damper motor in the throttle unit
- Defective throttle unit
- Defective engine control module (ECM).
Fault symptom[s]
- Malfunction indicator lamp (MIL) lit
- Poor performance.
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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.