Rear axle differential lock error

[___]

Took it to independent shop. Up on the lift, unplugged all sensors, compressed air on all connectors, plug back in, error gone. Beat up on the car hard to make it happen again (not that it took a hard beating for it to pop up prior to the "repair", but wanted to be sure). Car slides perfectly, doughnuts like it used to, no error.
$49 for 20 minutes of labor. As compared to the $300 I paid for BMW service to tell me I needed a $5.5k new differential.
So if you have the error... There's hope. Event if the car feels completely different when errored. That's what mine did, and that's because it threw the diff in safe mode based on wrong sensor input, not because the diff itself had any issue.

[stefan]

Just will add to this thread, I hit a texas gate at speed and it caused a noise that sounded like a rock in the heat shield. After inspection, everything seemed ok, noise went away, and then that error popped up. Clearing it would cause it to come back a few hours later. Ended up being the servo motor for the diff under warranty, but presumably an expensive fix outside of warranty.

[cbertels]

Reviving an old thread but the info here saved me big time. I had the dash light up like a Christmas tree showing differential codes and wheel speed codes. Out of warranty and I don't drive the car much right now (a few times a month).

Took the car to an independent dealer recommending the diff be replaced at a cost of roughly 5k in parts and labor. Also showed the wheel sensor was bad. Had them replace the sensor and lights gone and issue seems resolved. Total repair cost of roughly $250.

It's not just the dealers but we'll respected Indy shops don't always get the diagnosis right. The info in this thread and forum are amazing and saves me a few grand. Hope this helps others.

[J22 RSA]

Firstly thanks for all the above help in locating this issue, however I have a new problem that has not been listed here in relation to the GHAS and Diff Lock error.

I have a M2 which has the same GHAS and Diff as the M3 & M4 I believe.

I had the error come up when starting the car a few weeks back and then it went but came back on permanently.

I used my bimmer link to try and clear the code but it would not communicate with the GHAS, code D35432.

I had code 4809AB too, DSC control under voltage, after some digging I saw that some people replaced the battery, mine was 62% so I replaced it and nothing has changed so that rules battery under voltage out.

I then came back to this thread and checked all the plugs leading to the diff, cleaned them with electrical contact cleaner, nothing solved still.

I will not go to BMW with the car as it is modified but not mapped, plus out of warranty, I have read that they may try and fob me off with a new diff and ££££ bill, I know the diff is fine as there is no noise and it was perfect until this electrical error, just had the seals done too.

Anyway I decided it was the GHAS that must have given up the ghost. I ordered one online from a breakers that matched my car 2017 M2 LCI and it is on the way. £90 compared to the £500 BMW quoted (I still feel that is high as I have seen £200 mentioned here) plus coding.

Curiosity got the better of me and I decided to strip the right hand side of the boot ready for the new module, I unplugged the GHAS and shock all the terminals were corroded/rusty!

Opposite the GHAS there is a rubber bung that takes the wires from the modules and loom to under the car and into mechanical parts.
This bung was not seated in the metal panel of the car, therefore allowing moisture from under the car to get into the rear quater where all the essential ECU's are... hence the corrosion as the GHAS is the lowest module in the that area, it was not swimming with water but condensation was present.

I thought jackpot and cleaned the terminals and plug, however this has still not cleared the fault so I still think the GHAS is broken. A Snapon solus cannot communicate with the GHAS too, so the fault remains. (fuming)

I'm hoping the new GHAS once coded will be fine, I may need new plugs but hopefully not, in the meantime I still have an open diff and I am one wheel peeling everywhere....

Top tip, you can get to the GHAS by removing the plastic storage bin in the boot liner, for a module change you will need to take it all out though, but to check your bung this is all you need.

I will follow up with what happens once the new module is fitted, "M"erry Christmas!

Even if you don't have this error I would check your bung (no pun intended)

Pictures of the GHAS (61358092583) & wire bung below.

[Dabeamerking]

Yea good find. Water corrosion will do that. I hope that is your fix

[Zstyle]

Recently got the diff lock error on a 2017 M3 (bone stock) 69k miles.

Errors:
482B86
482BAE
D3542F

Recently washed the car before the code came up and has never come up before.

If it is a a wheel or abs sensor, can anyone give a specific part number(s). I’ve read it could be a front or rear sensor. Only have BimmerLink to pull codes.

Curious why BMW would allow a fail safe to be a locked diff versus keeping it open….

Are there any problems if the error is not fixed?

[Zstyle]

Wasn’t able to find an Indy shop in time for my needs, so brought the car to dealer.

My problem was attributed to the servo motor for e-diff ground failed causing an open circuit internally. They be replacing servo motor tomorrow hopefully.

[HaidarKA]

Originally Posted by Zstyle

Wasn’t able to find an Indy shop in time for my needs, so brought the car to dealer.

My problem was attributed to the servo motor for e-diff ground failed causing an open circuit internally. They be replacing servo motor tomorrow hopefully.

Did the problem solved when they replaced the servo-motor?

[Zstyle]

Yes, the problem was solved with a replacement servo motor. Per dealership, 2 yr warranty & unlimited miles for service and parts.

*Wish i could've done it myself but the motor needs to be coded to ecu

[carbon-14]

I just did my rear diff bushings, diff plate & upgraded to DSS axles. I’m now getting the “rear axle differential lock out reduced” message… I’ve replaced all the ABS sensors as some have suggested and I’m still getting this message.

Shop I took it to says the rear diff temp is spiking upto 400* F. When this message comes up. And once temp comes down this message disappears.

[carbon-14]

Just to update thread with what my issue was…

My front and rear tires have a huge difference in tire diameter. Rears are 305/45/17 & fronts are 235/45/18. That’s 9% diameter difference… the car doesn’t like it and it throws the rear axle differential lock out message.

I switched fronts to my stock CS wheels 265/35/19 which is only 5% difference and error went away.