PRNDS Selector Lights all on Randomly & Stiff Gear Change
 

Have been lurking here a while trying to find out what's what with my A8 and any gremlins they come with. On a recent 370 mile photo trip, I noticed that all the selector lights were coming on. This usually occurred during three and four point turns down single lane roads and tracks. Wasn't sure at the time what the problem was, so switched off and on again, which cleared them. Have since come across several posts suggesting it might be the F125 switch on its way out.

However, I suspect I have a more pressing issue which may put the F125 switch issue into perspective. I was parked up yesterday for another half an hour on a 30-35 degree slope. When I got back, started the car up, and went to move it into drive. Had to use quite a bit of force to move it and there was a clunk when it moved from P to R. Not being mechanically minded, even I know that this doesn't sound good.

I've read other posts about replacing the gearbox and diff oil, and was wondering if what I described are signs of there not being enough oil in the transmission. That's question one. The second question is whether anyone knows someone who could check and change the oil here in Northern Ireland, who knows what they are doing. I've already had help from one of the forum members in respect of a contact for a LPG conversion.

BTW The car is a 2001 3.7 QS with only 55k on the clock. The car drives fine. Any help would be much appreciated.

Posting from my phone - need to read fault codes to confirm f125 fault but sounds likely given symptoms

Difficulty getting out of park is probably a slightly weak handbrake and nothing to worry about

Welcome! +++
Mua ha haaaa another 3.7 on the forum. . . . World domination!!!! :D

How good is your handbrake? If the car has come to rest on the stop in the gearbox, then it'll be hard to get it out of P.

Though could be low oil in the box.

Know someone who has the cable, so will give him a shout. Never know what other issues it might show up. Might try it this evening.


It's definitely a nice car to waft along in, but needs lots of TLC I suspect. Since I can't afford a D3 S8 (unless I win the lottery), then I want to sort the engine and transmission first, before getting a LPG conversion done like Ricky22buk on here. Will be a lot more friendlier to my wallet than the current 25mpg :)

Good question PsYcHe. Will have to go there again and check it out. Used to parking on level ground. Never had any issues on smaller 5-10 degree inclines.

So, managed to get the car scanned and beginning to wish I hadn't :(

I'll put the results in a separate post and ask for help there, but so far as the F125 switch is concerned, here is what I got:

17090 - Transmission Range Sensor (F125)
P0706 - 35-10 - Implausible Signal - Intermittent

So far it hasn't been a real issue (and will remain that way until dealt with) and only occurred during these 3-4 point turns. Hasn't gone into limp mode, but then I was just restarting the car as I didn't know what the issue was.

If all the gear selector lights are lit up red then the gearbox is in limp mode, which sticks the car in 3rd gear IIRC

OK. Useful information should it happen when I'm on the road. Because I only got it during the 3-4 point turns, and was then stopping and starting it again, I wouldn't have experienced it going into 3rd.

Anotherone for handbrake. Try facing the car up hill, always used to find it worse when facing downhill.