Diagnostic trouble code (DTC) information ECM-986A
Condition
Diagnostic trouble code (DTC) ECM 986A is stored if the engine control module (ECM) registers an internal fault where the input signals from the throttle unit position sensor are interpreted by the normal engine control functions as having exceeded their minimum or maximum limits, while the internal monitoring function interprets the input signals from the electronic throttle unit position sensor differently.
Substitute Value
The engine speed (RPM) and torque are limited to a calculated normal operating range.
Possible Source
- Defective engine control module (ECM).
Fault symptom[s]
- Maximum engine speed (RPM) too low
- Cruise control does not function at all
- Uneven idle
- Malfunction indicator lamp (MIL) lit.