4x4 light on and abs light on

[Jerry]

changed fuel pump on x5 running smooth now, but 4x4 and abs lights on wont go off when i turn wheel lock to lock .

battery  kept going flat so wonder if that caused it,  as these lights have never been on before

any info would be welcome.

[Greydog]

X5's are renowned for being sensitive souls when it comes to the battery condition. First step I would get the battery checked, if it isn't holding a charge it may be dying. If the battery is OK then make sure its fully charged remember it can take up to 12 hrs to fully charge, I have a Ctek battery conditioner/charger and use it at least twice a year. 

When you are sure of the battery and it's condition try rolling forward going lock to lock again, if that doesn't cure it I would back track over what you did changing the Fuel pump just in case you disturbed a connector. My money however would be on the battery, I had issues with my 4.4 which drove me nuts battery test said OK the car never failed to start but I would get random fault warnings even though the car ran as smooth as silk. Then I read the code label on the battery it was 10 years old !! must have been the original a new battery fixed my problems the crazy thing is that battery is still powering an electric fence system with the help of a solar charger. 

[Jerry]

Diagnostic could not communicate with transfer control unit plus battery losing charge on tester .think I go with control unit first battery under leg tank bit more cost 

[Greydog]

Morning Jerry

My 4.6 is the simple cousin (no X drive) your 2 posts are related so I will try to help with both here if I can as any diagnostic by remote control is really a best guess.

Your 4.8 has X drive the difference between our cars, mine has a simple chain driven transfer box giving a fixed front rear split yours has the X drive transfer case which has an electric motor controlled clutch to vary the front rear power split dependent on wheel slip. You say diagnostics doesn't see the transfer control unit? Did it before? Fuse 46 controls the X drive try checking that, check the motor connector at the Transfer box, check you haven't disturbed the ABS sensor at the rear when you were underneath (the system measures wheel slip by ABS)

When doing the lock to lock thing the car has to be moving when you do it and sometimes it may take a mile of driving for things to reset.

I don't know what diagnostics you have but it needs some dedicated BMW software INPA or similar to see some modules

[Jerry]

Afternoon I put a fuse in slot 46 not sure what ampage could someone give info now 4x4 and abs lights go out for 10 seconds then pop back on do I need to get them cleared help

[Greydog]

Morning Jerry

You say you put a fuse in position 46 was it missing ? I believe it should be 7.5 amp rating. If the fuse is sound I would try clearing all stored codes you could also try disconnecting the battery for 30 mins. Have you tried driving forwards going lock to lock. If the fuse was there or blown there is a cause you must have a dead short somewhere.

If the fuse was missing you have to wonder why, had a previous owner removed it to cover a fault? The Xdrive system controller gets inputs from (1) The wheel ABS sensors to measure slip and either apply the brake or more torque the signals come from the ABS system controller. (2) Throttle position sensor. (3) Steering Angle sensor (4) Wheels speed sensors. There are probably many other links through the bus system from DSC Hill Descent ASC.

From a brief conversation with my friendly BMW specialist his view would be first make sure all connectors are clean and fully on (especially where you were working) check the fuses, if all is OK then make sure the Xdrive actuator on the Transfer box is working (these are known to give issues). The ABS controller is also a possibility as a culprit but he says there are several companies that rebuild them. Last thought he asked if you had had the transfer box fluid changed? apparently it requires its own fluid not the same as my simple cousin.

I hope this helps Jerry 

[Jerry]

All done turns out some fuses where missing when air suspension was removed replaced a few  Diagnostic could then communicate with module .I put my hands up don't think I helped fumbling around , took for test drive Tec guy says just got slight play when pulling off drive shaft but hardly notice it not be racing off from lights at my age

[Jerry]

Forgot to say big thanks for all info.

[Greydog]

Well done Jerry, persistence pays in the end, if anything posted helped that's what the Forum is about and thanks for the update 

So it's on coils not air suspension that explains a lot. You may get advisories popping up on the instrument cluster which could be why there were missing fuses, you can code these out using BMW 1.4.0 software or Carly it is just a case of going into the program IKE if I recall and un-ticking a couple of boxes (if you use 1.4.0 you will need an old laptop running Win 7 or 8 or set up a Virtual Machine on newer) 

Check the centre bearing on the prop shaft also the rear suspension bushes odd tyre wear or excessive camber is a give away sub frame to body bushes as well they only seem to last about 80k.

I brought a kit off the bay of e 2 years ago as rear adjustment was hard for the garage to get in tolerance, the difference is massive

Now drive it and enjoy it