Check engine light has left the chat

[simonasaur]

Hey y’all,
I recently unplugged what I believed was my traction control module. It’s located just behind my drivers seat (LHD). I started the car just like normal and it seems to run the same as it has the last 6 years for me. I tested the TCS button, and it no longer illuminates, as I had intended/ expected.

Here’s the question; I noticed when I start the car, they’re is no longer a check engine light. It doesn’t illuminate on the dash at all. I’m very accustomed to this light over the years, and am curious if it was somehow attached to the module I unplugged? Any help is always appreciated.

Sam

 

[Old Guy]

The CEL is on a separate circuit so meddling with the TCS should not affect the CEL operation. The CEL is either burned out, you have a dash wiring problem, a harness problem or the output transistor in the ECU that controls the CEL has failed. The CEL bulb get +12 v from a common bus in the cluster. That could have failed; but, then you would have a whole bunch of other stuff in the cluster that does not work.

The CEL is connected to ground by a transistor in the ECU to illuminate it. Get the service manual and check the pin out for the ECU to find the connection for the CEL. Remove that plug with the CEL connection and ground that pin on the wiring harness side and switch the ignition on. You should have continuous illumination of the CEL as long as the ground is connected. If you do there is a problem with the output in the ECU. If you don't the problem is somewhere between the Ecu harness plug and the bulb in the cluster.