Getting up arrow and check engine light on after repairing PNP switch Topic is solved

[aeg]

Another note. My guess would be that inside the switch, the innermost trace (closest to the circular hole) is ground, the next is PA, then A, then B; and the outermost two traces are shared between C, 50S and BL; and there is an electrical connection between the innermost two copper brushes at the wiper arm. Again, just a guess. So maybe in your case, the problem is with the middle copper brush.

[rgroove54]

Hi aeg, I opened up the PNP switch again and did the rebuild by stretching the three springs a lot more this time. I put it all back together and the up arrow and check engine light has gone out!!! I cleared the DTC codes and no longer have any transmissiin errors. When I re-opened the switch, I noticed that the middle copper contact looked like it was 'wedged' into the slot. I guess the spring it was on, wasn't stretched enough the first time? So if it was that, you were spot on guessing it was the middle contact. I hope that's all it is. I'm yet to do a test drive to see how the gears shift. Your troubleshooting tips on the electrical side have been invaluable and I've learnt a lot, so many thanks for your time.

All the best for the new year.

[rgroove54]

Hi aeg or anyone else. Following on from my last post and after realigning the PNP switch where I get reverse lights ok, it's starting in Park and Neutral fine and no up arrow and check engine light on, I went for a test drive. I was still losing gears when I stopped or slowed down. Managed to get the car home and rechecked the TCU pins 3,4,5,6 against pin 29 in all gear positions. I was getting continuity in all the gear positions correctly. So, the Comms between the TCU and PNP switch is still fine. Anything else I could check please?

[scot850]

Did a quick skim of the info in this post, but did not pick up anywhere if the trans fluid level was checked or if/when the trans oil was last changed? Apologies if I missed it and it is there.

Neil.

[rgroove54]

Did a quick skim of the info in this post, but did not pick up anywhere if the trans fluid level was checked or if/when the trans oil was last changed? Apologies if I missed it and it is there.

Neil.

Hi Neil, the ATF fluid was changed twice back in Sept 2025 with Dexron III. I checked the fluid today and it looks a bit overfilled. I read a post by MVS member Cn90 (I think) and he said a little overfill won't hurt.

Shall I leave it or drain and refill again?

Many thanks for your thoughts.

[scot850]

When you say drained and filled, do you mean you just pulled the drain plug and refilled with 3.5 liters each time or you did a flush?

Did you use the correct ATF?

When you show that dipstick picture above, was that with the engine and trans oil hot?

Neil.

[erikv11]

The price is steep but here's one way to eliminate all PNP woes viewtopic.php?t=107560

[rgroove54]

When you say drained and filled, do you mean you just pulled the drain plug and refilled with 3.5 liters each time or you did a flush?

Did you use the correct ATF?

When you show that dipstick picture above, was that with the engine and trans oil hot?

Neil.

Hi Neil, I drained and refilled with 3.5 litres. I did it twice with 50+ miles in between each change. I'm using Mannol Dexron III - https://www.mannol.de/products/automati ... dexron-iii

Yes, the engine was hot. Before I checked the level, it was driven/warmed up for 30 minutes, went through each gear with a count of 5 seconds and waited for over 3 minutes before reading the ATF level.

[scot850]

m Having seen all the work you did on the PnP switch, if you are still getting slips or rough changes in gears it may unfortunately be a bad transmission. Do you have AWD or FWD in your car? The V70R only came in AWD in North America as far as I know, but I believe it had a FWD version in Europe.

It could be the solenoids are dirty or failing. There was a rebuild kit for that but the whole operation is beyond my paygrade unfortunately. There are others that have done this and it may save your trans. However, you may be quicker swapping in a good used trans. Not too terrible on a FWD, a bit more challenging for a AWD because of the angle gear.

Neil.

[rgroove54]

m Having seen all the work you did on the PnP switch, if you are still getting slips or rough changes in gears it may unfortunately be a bad transmission. Do you have AWD or FWD in your car? The V70R only came in AWD in North America as far as I know, but I believe it had a FWD version in Europe.

It could be the solenoids are dirty or failing. There was a rebuild kit for that but the whole operation is beyond my paygrade unfortunately. There are others that have done this and it may save your trans. However, you may be quicker swapping in a good used trans. Not too terrible on a FWD, a bit more challenging for a AWD because of the angle gear.

Neil.

Hi Neil, mine is FWD. I'll look into the solenoids, but thought a scan would highlight any issues with them? Don't have the budget unfortunately for a transmission swap.

Thank you for your thoughts.