Reduced Engine Power Mode
Engine power has been reduced due to a fault detected in the system.
Heads up: this code wasn't in our hand-written library yet, so DiagCoach AI built this page on the fly. Double-check critical specs against service info before condemning parts.
What it means (plain English)
When the engine computer sees problems like high temperatures or bad signals from sensors, it limits the engine power to prevent damage.
What the computer is actually seeing
The Engine Control Module (ECM) detects abnormal readings from critical sensors or temperatures that exceed safe operating limits, triggering reduced power output.
What a healthy reading looks like
Normal sensor values for things like coolant temp should be between 190°F to 220°F, and voltage readings from sensors should be around 0.5V to 4.5V, depending on the type. Any readings outside this can trigger the fault.
Guided diagnostic — the DiagCoach way
Don't just throw parts at it. Walk through these in order — each step tells you whether to keep going or stop and fix what you found.
- 1Check wiring and connectors for corrosion or damage related to the temperature sensors. Repair as needed.
- 2Verify coolant level; if low, fill and check for leaks before conducting further tests.
- 3Use a scan tool to check for additional codes that may indicate related issues. Pay attention to any PIDs that relate to temperature or pressure readings.
- 4Monitor the engine temperature while running; if readings exceed 220°F, investigate cooling system issues including thermostat or radiator performance.
- 5Check for excessive back pressure in the exhaust system; replace or clean components as necessary.
Common causes
- Faulty temperature sensor
- Wiring issue between sensors and ECM
- Engine overheating
- Malfunctioning turbocharger
- Exhaust restrictions or DPF issues
Typical repair cost
$$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
It's not safe for long drives as it indicates potential overheating or sensor issues that could worsen.
Will this code come back after clearing it?
If the underlying problem isn't fixed, yes, it will likely return.
Why does it pair with over-temperature codes?
It's designed to protect the engine from overheating by reducing power to limit heat generation.
Working a real vehicle right now?
Let DiagCoach walk you through it live with your specific symptoms, vehicle, and what you've already checked.
Start guided diagnostic →