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My car went into limp mode with a CEL. I pulled over and scanned it. One of the codes was P1686, indicating a high signal from the OMP. I have tried to search to find all the answers, but really I have just collected some ideas (see list of references below).
I managed to get the battery and battery box out to expose the front of the OMP. I got the power/data connecter on the left to release. Based on this thread and this article I need to open the thing on the passenger side to reset it to full clockwise (I think). But I'm having trouble figuring out which bolts or screws to release. Does anyone have better images to explain this job?
Similar happened to me. After going through the same research that you have I made the choice to just replace the OMP (since mine had over 100K miles on it anyway). Just couldn't make myself comfortable that I would make the adjustment properly after going through all the work to pull the OMP and then reinstall it. Happy with that choice, has been running fine ever since and actually consuming just a wee bit less oil tan was the case before the replacement.
It is crazy expensive. After shopping around I bought mine through Mazmart. However, I justify that spend in my own mind as an offset to how much time I would have gambled in trying to do the reset, remounting it and seeing if it was working, finding out it wasn't and then having to remove it again and replace with a new one anyway.
So can anyone help me understand exactly which bolts/screws to release in order to just do the reset? I think I'll at least try the reset once before committing $1k to a new part.
So can anyone help me understand exactly which bolts/screws to release in order to just do the reset? I think I'll at least try the reset once before committing $1k to a new part.
I'm interested in this because I've had my OMP off and on what feels like at least a couple dozen times and I've been expecting something like this to happen.
It hasn't -- Knock on wood .. my head will do (no not that one you dirty buggers)
I would just clear the MIL -- add 8oz of premix to my tank and see if it happens again.
I got a private message from dannobre, but wanted to share here for others' benefit and hopefully to get some further clarification from others.
In this first picture, you see the black connector harness (for the position sensor) and two screws.
Then in the second picture (a collage of two images) you see the internal components.
dannobre's response was
There are 2 screws on the positioning switch......
If you haven't removed the switch before you should leave it on and just move it a bit. reset the ECU and see if it is working. Maybe go 2 small moves in one direction...and if that doesn't work then you can try going the other way
I guess I'm still confused. I wouldn't expect the outside of this to move, but it sounds like the part with the black connector housing will rotate.
I noticed what seems to be a slot opening for each screw, which would allow some movement if I loosen the screws, but there's no way that small slot opening allows for the amount of travel shown in the second image.
Also, in the pictures with the piece removed, I don't see the two receptacles for the screws. Where do they attach in the inside photo?
I got a private message from dannobre, but wanted to share here for others' benefit and hopefully to get some further clarification from others.
Like I said in the PM...there is a lot of not so good info in that thread. The switch allows more movement than the slots...it is very similar to a throttle positioning switch. The slots allow adjustment so the ECU sees the correct resting point for want of a better word. If that is off the ECU thinks the pump has malfunctioned and puts the car in to limp mode
Try what I suggested and see if it works. If you have taken the switch off that is a different matter and then you will have to reset it to have a place to start
05-17-2016, 08:07 PM
