Diagnostic Trouble Code (DTC) Information

Diagnostic trouble code (DTC) information ECM-91AC

Condition




The engine control module (ECM) checks that the throttle follows the requested throttle angle from the engine control module (ECM). The diagnostic trouble code (DTC) is stored if a fault related to the engine or control of the engine in the throttle unit is detected.
The diagnostic trouble code (DTC) can be diagnosed when the car has been test-driven in various driving conditions.

Substitute value
- The cruise control is disengaged when the fault is active
- The supply to the throttle unit is switched off, causing the throttle disc to turn to the return position.

Possible source

Throttle jammed
- The throttle is sticking or is blocked (e.g. dirt, icing, etc.)
- Damaged throttle unit.

Faulty signal
- The throttle is sticking or is blocked (e.g. oil film, dust, icing)
- Damaged throttle unit
- Damaged engine control module (ECM).

Actuator current too high
- Short-circuit to supply voltage or ground in the wiring for the throttle unit
- Open-circuit in the wiring for the throttle unit
- Damaged throttle unit
- Damaged engine control module (ECM).

Fault symptom[s]
- Deterioration in performance
- Uneven idle
- Cruise control does not function at all.