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Trans failsafe

Discuss the problems with your X5 (E53).
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Themoog2
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Trans failsafe

Post by Themoog2 » Sun Mar 03, 2024 9:31 pm

Here's a good one..
The 4.4 has gone in trans failsafe mode.
I've had it at the place where I had the transmission rebuilt but he couldn't get his diagnostic to communicate with the car.
I scanned the car when it was cold before starting yesterday to take a look. Only the ignition was on.
This time-
DD CAN timeout ASC/DSC
DC CAN timeout, electronic transmission management (EGS/AGS)
78 signal, vehicle speed
80 CAN BUS monitoring
82 CAN ABS/DSC signal
81 CAN timeout DME
20 wheel speed sensor front right transmits no signals
21 wheel speed sensor front left transmits no signals
68 steering angle sensor internal

Some of those may be explained as the car was stationary I’m not sure.
I took it for a drive for 30 min and it drove ok.
The heater blower motor would not work at all and the hill decent switch was illuminated and would not turn off.
No lights on the dash.
During the drive I reconnected my scanner but it would not communicate with the car at all.
Got home and switched off. When I restarted it was in trans failsafe mode with no speedo or rev counter and the temp gauge was right over in the red again.
I've looked in the electrics box under the scuttle and it's dry but haven't had chance to look at the fuse board behind the glove box for anything.
Something is going on that I can’t figure out.
Anyone around the globe got any ideas?
Anyone know a place that can help out near Cambridge UK?
If this reads funny it's because I copied and pasted it from another forum so apologies.

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Alan Gunn
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Trans failsafe

Post by Alan Gunn » Mon Mar 04, 2024 4:54 am

Thought i had read this before.
Fingers crossed for help.

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X5Sport
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Trans failsafe

Post by X5Sport » Mon Mar 04, 2024 6:41 am

You’ve probably tried this, but is the battery OK?
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Themoog2
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Trans failsafe

Post by Themoog2 » Mon Mar 04, 2024 6:34 pm

Well it has crossed my mind but it seems to be ok on my stabber.
It's normally left on a ctek anyway.
What I have noticed however, is that my scanner can read the car when it's cold but after 30min or so when it's hotter it won't.
Just this evening I've removed the glove box to check all the fuses etc and everything seems to be in order. No dampness there or under the scuttle.
Next check will be the plug on the ABS module but that involves removing the headlight - which is bizarre as the driver bulb light went only yesterday. It's as if it's pointing me in that direction... I wish.

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marti
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Trans failsafe

Post by marti » Tue Mar 05, 2024 7:12 pm

Have you checked the battery voltage.....

Themoog2
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Trans failsafe

Post by Themoog2 » Fri Mar 08, 2024 7:25 am

Yes that's OK.
I think I'm narrowing it down..
It can't be the ECU as the engine starts and runs OK. So that just leaves the TCM and Abs modules or something that they use for function ie wheel speed sensor etc. As the cluster also requires a signal from the wheel sensors that would point towards the abs module which is a common failure on vehicles anyway. In fact I've had one fail on my E39 and my Mini 1.
I have an auto electrician coming on wed to run a better diagnosis with the engine cold so we may get some codes to work with.

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Trans failsafe

Post by Themoog2 » Wed Mar 13, 2024 7:40 pm

Latest..
All the symptoms points to the abs module so I whipped it out today.
Bit tricky I must admit..
Anyone recommend someone who can test / repair these modules?
I've emailed a few from a search so we will see.

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Trans failsafe

Post by X5Sport » Wed Mar 13, 2024 9:11 pm

Autotronics in Leicester has come up before. Not yet had to use anyone personally.
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Themoog2
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Trans failsafe

Post by Themoog2 » Thu Mar 14, 2024 10:46 am

It's being collected tomorrow to go to Ecu testing in Derbyshire.
I the mean time I need to go over all the earth connections etc.

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Trans failsafe

Post by Themoog2 » Wed Mar 27, 2024 5:56 am

Update..
Ecu Repair had the module. They called me and said it was faulty but beyond repair unfortunately. Drat!
Had to plump for a used one from Ebay which cost me £200.Bit of a gamble but it's got a 3 month warranty.
Anyway, it arrived (abs pump included) so I whipped it apart and put the used module on my car.
I've had it running and drove it about for several miles and everything seems OK thank goodness.
The heater blower is a different story - I had a spare new Ebay hedgehog that I thought I would install. Mistake. The blower motor was erratic and when I switched the car off it went to full chat even with the key removed. I've put the old one back in for the time being until a new one arrives. Paid a bit more for a proper one this time.
So that's it so far. MOT booked next Thurs so let's see what surprises that brings. 🤔

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Alan Gunn
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Trans failsafe

Post by Alan Gunn » Wed Mar 27, 2024 8:22 am

Needed coding ????.

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Trans failsafe

Post by Themoog2 » Wed Mar 27, 2024 8:55 am

Nope. Plug and play. Same part number tho. I did the same on my old E39 several years ago as that module had already been repaired when I took it off..
I've only driven it for 4/5 miles at the moment but so far so good.

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Alan Gunn
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Trans failsafe

Post by Alan Gunn » Thu Mar 28, 2024 6:04 am

:thumbsup: :thumbsup: :thumbsup: :thumbsup:

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