Diagnostic Trouble Code (DTC) Information ECM-983A
Condition
The diagnostic trouble code (DTC) is stored if the engine speed (RPM) exceeds 520 RPM and the engine control module (ECM) registers an internal fault indicating that the calculated engine speed (RPM) in the internal monitoring functions differs from the normal calculated engine speed (RPM) in the engine control functions. The diagnostic trouble code (DTC) is diagnosed with the engine running and at an engine speed (RPM) above 520 RPM.
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 work at all
- Uneven idle
- Malfunction indicator lamp (MIL) lit.