Check Engine Light Diesel Car
What is the Check Engine Light?
The Check Engine Light (CEL) is a warning light that appears on the dashboard of a vehicle when the engine control module (ECM) detects a problem with the engine or emissions system.
The CEL can be triggered by a variety of different problems, including:
- Loose or faulty gas cap
- Faulty oxygen sensor
- Faulty catalytic converter
- Faulty EGR valve
- Faulty turbocharger
- Engine misfire
- Diesel particulate filter (DPF) problems
What to do if the Check Engine Light Comes On
If the CEL comes on, it is important to take the vehicle to a mechanic as soon as possible to have the problem diagnosed and repaired.
Driving with a CEL on can damage the engine and emissions system, and can also lead to increased fuel consumption.
How to Reset the Check Engine Light
In some cases, the CEL can be reset by simply disconnecting the negative battery terminal for 10 minutes and then reconnecting it.
However, this will only reset the light if the problem that caused it to come on has been fixed.
If the problem has not been fixed, the CEL will come back on after a short period of time.
Diesel-Specific Check Engine Light Codes
In addition to the generic CEL codes that can be triggered on any vehicle, there are also a number of diesel-specific CEL codes.
These codes are typically related to the diesel fuel injection system or the emissions control system.
Some of the most common diesel-specific CEL codes include:
- P0234 – Turbocharger overboost
- P0299 – Turbocharger underboost
- P0401 – EGR valve malfunction
- P0402 – EGR valve position sensor malfunction
- P0403 – EGR valve vacuum regulator malfunction
- P0404 – EGR valve flow sensor malfunction
- P0405 – EGR valve temperature sensor malfunction
- P2002 – Diesel particulate filter (DPF) efficiency below threshold
- P2003 – Diesel particulate filter (DPF) efficiency above threshold
- P2004 – Diesel particulate filter (DPF) regeneration failed
Conclusion
The Check Engine Light is an important warning light that should not be ignored.
If the CEL comes on, it is important to take the vehicle to a mechanic as soon as possible to have the problem diagnosed and repaired.
Ignoring the CEL can lead to engine damage, increased fuel consumption, and failed emissions tests.
