A good friend of mine (who also happens to be a very talented Volvo mechanic) told me that there are instances where a simple ETM reset procedure can help with rough idling, or to simply smooth out roughness after cleaning the throttle. Essentially, the procedure re-calibrates the closed position of the throttle plate which is important if you’ve removed carbon buildup that was affecting the previous calibration.
He noted that it’s a good idea to perform this simple procedure after you’ve tinkered with the ETM – even if you’ve removed it and not cleaned it. So if you remove it as part of your PCV maintenance (ie taking off the intake manifold) you should reset it.
Like I said, it helps the the car re-find/calibrate the ETM’s closed position.
ETM Reset Procedure Steps.
- Turn your engine off, leaving the key in the intermediate position (I) for one minute (I left it for 70 seconds to be safe).
- Turn the key to the locked position position (0) until the car has fully shut down (three minutes).
- Re-start the engine to note any changes to idling and ETM characteristics.
The ETM Reset Procedure is not a Miracle Cure.
Now, this ETM reset procedure isn’t any kind of miracle cure for rough idling, but it’s something you should at least try.
I performed the reset after cleaning my 2004 Volvo XC90 throttle plate in-place and I noticed a difference right away. The car was doing some hunting at idle, trying to find its “safe place” which was difficult as I had removed quite a bit of carbon, which opened the throttle opening slightly – just enough to mess with the idle.
After the ETM rest on my Volvo, my idle issue was gone. Give it a try. It’s easy and it doesn’t cost a dime.