The error code wheel of fortune continues - This time P1242

[RTB]

Originally Posted by JeanLuke

The PCI bus runs at 0V=low and 7.5V=high. The CAN bus runs at 1.5V=low and 3.5V=high. The WG has both present, with the comms between the ECU, ABS and TCM are on the CAN bus.

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Good to know. More reading to do for me it seems. Thanks for the tip.

[JoergM]

So I changed the electric plug adaptor and sure enough, I had plenty of oil on the connector. I replaced it and to my surprise I had tranny fluid pouring out once I removed the adaptor (not the plug). I have seen other instructions but never saw I fluid coming out in the amount I had it. I guess this was the excess of the fluid I added

Question for the ones who have the OEM dip stick too. How do I read it correctly? At the moment it seems to be on the second line from the bottom. Right after I replaced the adaptor, it was even on the first line only. There are other lines too but I am not sure where the level supposed to be (see picture).

Nonetheless, the problem seem to be solved. I took the Jeep for a test drive and it was shifting nicely and not acting up at all.

Thanks to all who had given me advise, really appreciate it.



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[JeanLuke]

It should be between the top two lines when measured at 87 degrees C. Use WJ Diag to read the temperature, but the transmission must be in drive for a valid reading. If it's not in drive, it reads the coolant temperature instead. I have no idea why Chrysler/MB thought this was good programming.

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[Adrian D]

Originally Posted by JeanLuke

It should be between the top two lines when measured at 87 degrees C. Use WJ Diag to read the temperature, but the transmission must be in drive for a valid reading. If it's not in drive, it reads the coolant temperature instead. I have no idea why Chrysler/MB thought this was good programming.

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One of my old bosses used to work for MB, he recounted a story where one of the guys involved in the discussions about UDS (Unified Diagnostics Server, basically what we can read through OBD), a mechanic, really wanted the umlaut for anything with oil in the name.

There we go, silly things have happened in the past and I bet there are tons line this

[JoergM]

Gaaaaaah. I thought i finally got my transmission problem fixed but yesterday I was back to square one.
Thought I take the Jeep to town with a trailer and wanted to pickup some stuff. Realised pretty fast, that the transmission started to acting up but one in reverse it came back online.

When I then parked the car on the side and restarted it, I had same problem as before. There was a P703 brake switch signal circuit - Plausibility After Init which I could clear but then again ... no code. No matter what I did, I could not get this thing going. Then I got the transfer case in low and finally go the car going. Initially in low rev, I could feel the transmission biting on but then when I try to accelerate it jumped out again. It took me roughly 15 to 20 min to get this thing really going again, although I am not sure what I did so that it was back online.

Back home I checked again the transmission plug but is was bone dry so no oil here. The only thing I can still think off is some oil inside the plug since only cleaned the contacts outside but did not clean up inside the plug (not sure if this is needed but I saw it in some youtube video.

I guess I am starting to running out of options and have to look on some of the electric boards for some issue. Not really something I was hoping for.

[RTB]

Was it only 703 you had? Any chance there was a P0572 or P0573 as well?

I'd still be pulling the TCU and carefully cleaning the main plugs going into it.

Seems the brake switch has 2 switches. Primary ad Secondary. Might be worth looking around there too.

[RTB]

Are you able to activate cruise control? I had a car once that the cruise control would turn off every now and then.

Turned out to be a faulty brake switch that would activate on it's own and cut cruise. Wouldn't have known I had a faulty switch otherwise.