Transmission problem.

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SHAUNE55

Banned
Joined
Jul 20, 2011
Messages
143
Location
Manchester.
Car
'01 E55 : '99 E55
Hi,
I'll try and give you the brief version of the story as it's quite long!
The clip came off the gear rod on my 2001 E55 and I was in drive at the time, but not knowing this I was trying to park so I moved the lever and only had forward.
I found the problem and fitted a new clip, the car was fine but when I went to it a few days later it was showing R when in park. Eventually after running through the gears it started but still showing R, then after a while all went back to normal. This kept happening every day so I put another shifter on and same thing, but then that shifter went really bad and put it in limp with severe banging into gear. It wouldn't clear the code so I swapped the shifters over again and codes cleared car was fine.
Next day same problem but I had to clear the codes and then it was fine, it's as if something got damaged when the rod came off which is now killing gear shifters.
When the car's warmed up it's perfect but the next day my display for the gears is wrong and no start without repeatedly moving the shifter, then it starts and if I turn it off then ignition back on I have to wait for R to turn to P and all OK....When warmed up I don't have to wait.
Here's what I got last time it was in limp mode, only one current fault P2602, after lots of searching found about 30 people who'd had that code and a new battery cured it but it didn't cure mine.
Everything points to the shifter being faulty but I'm reluctant to fit a third because of it already killing two.
Any ideas what could have been damaged when the box was telling the TCU it was in drive but the shifter was telling it other things, and therefore killing shifter PCB's?
First that comes to mind is the TCU itself, but with the fact it corrects itself when warm could mean the conductor plate?
Today I'm back in limp mode after running it with the shifter plug off to check connections and now I have no gear display.
By the time I drive it a mile to my mates computer it shows no codes because it's working, although now it should be the same as the pics.
Any advise would be welcome as this is driving me round the twist!
Cheers.
 

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Check the engine mounts haven't sagged stressing the linkage. That may be what pulled the clip off in the first place.

I don't think the gearbox tells the TCU what it's doing other than the speed sensors, all input comes from the selector.

Those codes are happening because the battery voltage is low, but is restored after a few minutes running.
 
It did have new mounts before I bought it but I'll check them, all these problems I'm having could be pure coincidence and nothing to do with the rod. As I said it was OK after putting it back on then I didn't use the car for three days and that's when it all started.
I've got battery number 3 on at the moment and I've tried a fully charged battery straight off the charger in the morning, when I know it will be a problem but it was still the same.
I've tried putting a jump lead to the engine from - terminal in case it was a bad earth.
First thing I'm going to try tomorrow is changing the K40 with the other car and scan it again, I'll take snap shots of every screen. Reset the TCU code and if it's OK then I have to wait 'till the next morning.
Googling P2602 gives me about 30 people saying it was their battery.
Today I didn't finish in time to get to the garage and that's where my other one is due to SORN, but I tried the car and now I have a permanent blank display and only the occasional start in P or D.
IF it starts in neutral I have no gears engaging until I go to park, then take it out of park and I get gears with a slight bang.....Strange thing is I now have ESP/BAS/ABS lights that won't go off via lock to lock.
Had a new brake light switch last week.
So it does seem like a low voltage, I wonder if it could be the K40?
 
Well it's not the K40 relay.
I swapped it with my other car then I swapped the TCU which matched the part# that the EPC shows but it didn't work. So the later one my car has fitted must be required, obviously it wasn't backwards compatible to the original unit. I'm presuming then that something else in the car has been changed to only accept the later one.
I didn't want to try recoding the earlier one in case I ended up needing two!
Anyway cleared the codes to get it out of limp mode and had to clear a code from the traction unit to get the BAS/ABS/ESP lights off.
Car drove superb with the gear display perfect, I left it parked up for 3 hours and the display went blank again, now I'm just waiting for a TCU to arrive and see what happens when I fit that.
From what people have said it should just plug straight on but if not I'll have to try to code it.
So when the car is warm it works and cold it doesn't, if the TCU doesn't cure it then I'll have to investigate the conductor plate...I'm thinking maybe to do with fluid temp?
My fingers are crossed that it's a component in the TCU that is failing when cold.
 
If I wasn't bald I would pull my hair out!
Plugged in a used but correct part# TCU, gear display still wrong but car started every time so I went round to put it on the computer. Cleared a couple of faults and left it 10 minutes and problem still there but different, at last count the dash display is correct but sometimes I have a very slight bang into gear and sometimes not. When I start the car and put it in D the tip works and then when I drive off it changes up to third but no higher and tip stops working, then when I stop it stays in third until I turn it off and on again.
Then the tip works when stationary until it changes up to third, I didn't have much time to play around on the diagnostics because it was 4.30 and they were getting ready to shut up shop.
Does this sound like I now need to code this TCU? or if it needs coding would it not work at all, also I would have expected the diagnostics to say it had the wrong version code?
Bonfire night is fast approaching and if I've not sorted it I won't have to collect wood!!

The problem is that most of this will be irrelevant either in a couple of hours or in the morning when the symptoms will have changed again.:confused:
 
Have you fitted a new battery yet?

Yes, after trying one of a working car.
I also checked the rod adjustment again because today it was saying (diagnostics) that it was between gears.
I'm expecting another shifter assembly tomorrow but since that rod came off it's completely killed one and I don't know if the other is at fault occasionally.
All my mates at the garage are stumped because it's not a problem they've had before, if it would die and stay dead it would help.
It has a complete mind of it's own, just as it develops a pattern so I think I'm getting somewhere it changes to new symptoms.
I don't want my mates at the garage to get fed up with me going round using there computer so I try to give it a few days between.
I could do with my own!
I know for a fact a new shifter won't cure it although now it has a different TCU I live in hope.
I don't suppose resetting the shift pattern values (adaptation) could cure it?
I'm new to all this stuff, I'm a nuts and bolts mechanic. I prefer an engine to rebuild.
 
OK after 8 days of being lied to by a guy who said he sent me a gear selector when he hadn't and a forceful email later he finally sent it.
I put it on and dash display perfect straight away and starts, but I still have the problem of it only changing up to third and not changing back down until I turn off and restart the car then it goes back to first.
I don't want to try the original TCU in case that caused the first two selectors to go bad, I'll hook it up to diagnostics tomorrow.
Does this sound like the TCU needs the values resetting by doing the 4x 1-2 shift and so on?
 
That sounds like the speed sensor is sensing an implausible speed.
 
The speed sensor on the conductor plate?
Changing past third and changing down again wasn't a problem with the original TCU, that's why I was wondering if it needs setting in some way.
I found this on WIS but have no idea if this applies?
 

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You will need to set the variant coding of the TCU to the same as the car.
 
I reprogrammed the TCU to the car by following the on screen instructions on the diagnostic, I had to type the VIN in and click a couple of other steps and job done.
Took it for a spin and all is perfect...At last!
Thanks for the help.
 

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