Engine RPM/Vehicle Speed Limiter System
The engine RPM/vehicle speed limiter system is integrated into PCM. The purpose of this system is to prevent damage to the powertrain in overspeed conditions.
Whenever engine RPM or vehicle speed is detected, PCM will disable some or all of the fuel injectors. This will cause engine to run rough and DTC P1270 will set in PCM memory. When overspeed condition has been discontinued, normal engine operating conditions will be restored.