If this occurs, the engine computer will turn on the malfunction indicator lamp (Check Engine Light) in the instrument cluster, and the DIC will display the message ENGINE POWER IS REDUCED.Checked 2026-08-12
Limp mode
The common name for a protective state in which a control module limits engine power after a fault.
Also called: reduced engine power · failsafe mode · limp home mode
What it means
Definition
Limp mode is a driver's term, not a manufacturer's. It describes a control module capping power, throttle response or speed after certain faults, to limit further damage. Manufacturers use their own wording on the dash: Chevrolet's 2019 Silverado HD manual, describing a diesel particulate filter that has become plugged, states that the engine computer will turn on the malfunction indicator lamp and the driver information centre will display the message ENGINE POWER IS REDUCED.
Why a buyer cares
What it changes
It is one of the few faults that shows itself during a test drive rather than on a report, which is why a car that will not accelerate normally is worth scanning before anything else.
In practice
Where you meet it
Felt while driving as capped power, usually with a dash message and often the check engine lamp.
Two things that look alike
Not the same as
The check engine lamp reports a stored code; limp mode changes how the car drives. Either can occur without the other.
Read next
Related terms
Malfunction Indicator Lamp (MIL)
The dashboard lamp — usually labelled Check Engine — that the OBD-II system switches on when it confirms a fault.
Powertrain Control Module (PCM)
The onboard computer that runs the engine and, on many cars, the transmission.
Diagnostic Trouble Code (DTC)
The code an OBD-II system stores to identify which monitored system it found a fault in.
Where this comes from
Sources
The only verified manufacturer wording is GM's, in one diesel-specific context. Whether GM uses the same message for other faults, and what Ford or Toyota display, was not confirmed.