Auto box fault

[johnkarl]

Hello everyone, looking for some help if possible, I have a recently acquired x5 e53 with a 4x4 fault, it also has the red tyre pressure warning light next to it, the car starts first time and has full power, there is no engine management light on but it is stuck in 2nd or 3rd gear, I have checked and replaced the transfer actuator nylon cog, it was undamaged, I made sure it worked when it was off the car and it works fine, is there anything else I should try , hope someone can point me in the right direction

[Greydog]

Hi John Karl

Welcome to the Forum

First the 4x4 light can be triggered by several things, Low Battery voltage, ABS sensor faults, Steering angle sensor. However the fact it is combined with Trans Fail Safe which locks the transmission in 3rd  is more of a concern. I would carry out a Diagnostic Scan (as you seem to have a collection hopefully you have a BMW capable scanner) Clear down any codes then rescan to see what if anything comes back. The Red Tyre symbol is tyre pressure the E53 used the ABS system to measure rotation a flat tyre will rotate at a different rate and trigger the warning. With luck replacing a failed ABS sensor will sort the problem. Check Google for ABS sensor tests 

You don't say how many miles are on the car or whether there is any evidence of transmission services being carried out. I would change the fluid and filter as a matter of course, which hopefully will get you back running properly if not you may need a Transmission specialist to help which could get expensive

Fingers crossed its the simple fix

Dave

[johnkarl]

The car has 145k on it, there is no proof of any transmission oil changes and,  strangely I have just today,  ordered a icarsoft Pro that covers bmw, this should be here in a couple of days, will update when codes have been checked, thanks for your reply 

Edited April 10 by johnkarl
Spelling

[johnkarl]

OK quick update, I found a bmw dedicated obd2 cheap as chips local to me, so fo £10 I can have a play until my icarsoft Pro arrives, step one was to clear all codes and to my surprise the trans fail disappeared from the dash, I also removed the red tyre pressure warning light with this tool, quite impressed so far, so I started it up and all gears are working, even the manual side of the box is working, the only light on the dash now is 4x4 Amber warning lights, can't seem to get that one to stay off, so I know I have a problem, but at least the gear box changes now and the tyre pressure warning light has gone

[Greydog]

Morning John Karl

For me that would indicate either an ABS sensor is down or the ABS controller has a Fault (not unknown)

There are several companies that repair the ABS controllers at a reasonable cost and Warranty their work, the controller can be removed without disturbing the Brakes. An ABS sensor is around £20 make sure the reluctor ring is clean and not filled with crud (seen that a few times) fiddly to clean but worth it. Google will help with test procedures for ABS Sensors

Don't know what system you brought locally but it seems to have moved you forward so Good Buy

Dave