On and Off ABS Service/Brake assist service - BCM-0070

[Caerwyn72]

Evening all been having the same problems, was wondering if the control unit has to be coded in ?

Cheers all

[sreviz]

Yes can't be swapped. It needs programming.

[paddy74]

Originally Posted by sreviz

Yes can't be swapped. It needs programming.

The BCM? Are you sure? As far as I know, the BCM is changeable without new software. But at least it _is_ programmable (around 100.-EUR here in Germany), so you can always reload a BCM software that fits your car. Not like the CEM or the head unit.

[Caerwyn72]

Can anyone confirm this please before I send mine away lol

[paddy74]

*bump*
I'm sorry, my knowledge is, the BCM is changeable. But that doesn't mean I'm right...

Can someone please confirm or deny?
I once changed a BCM, but I can't remember, if I had any errors... I switched back after the original BCM was repaired...

[T689]

I don't think the BCM can be changed with another due to the chip inside recognised by the car.

On a follow up to my post #15, I did fix it a while ago;

I took the BCM apart (its a sealed unit) on my 2004 XC90 and the pins were not soldered to the board inside like later ones, but rely on a 'contact' fit.
I used long nose pliers and bent all pins, (each pin individually) slightly over to improve the contacts, then sealed the unit up again.

Once all back together and start the car, the fault will still be present, but this does not mean you haven't fixed it - you have to take it for a short drive and if you have fixed it, the fault will then disappear.

Mine fault has not recurred since (18+ months ago)

[aslan]

From Oct 2020 the brake assist service error was coming on and off until June 2021 it became permanent. Same BCM-0070 message.

Took out the motor, cleaned the connector and hurrah it's been good since then.

Prior to cleaning the motor again I was contemplating sending the motor and the BCM for repair to Xemodex.com

https://xemodex.com/us/available-ser...ontrol-module/

From their description, simply swapping the BCM with another used BCM probably won't work? The software has to match the VIN.

[Slevin]

Cant swap the bcm, it needs programming. but can swap the pump itself.

[T689]

Okay, 21 months later, ABS light on 90% of the time including startup.
When plugged code reader into car, returned fault code BCM0070.
I’ll update how I get on…

[T689]

UPDATE:

Although same DTC, cause of fault is different from the one I had 21 months ago/16,000 miles ago (where I repaired the ABS BCM - that fix is still going strong)

This time, as the diagnostics were saying "ABS PUMP - no power", after checking the fuse was fine first, then I thought favourite would be to check the ABS pump motor.

Took the motor off, and found quite a lot of carbon deposit.

Cleaned the brushes and internals, light grease on the shaft near the bearing, and installed back on the car.

Put everything else back, ABS light cleared.

Bearing in mind it was on 90% of the time and upon startup before I cleaned the ABS pump motor, now it hasn't returned after 5 test drives.

Diagnostics not showing any fault present either.
Odometer: 130,000 miles.

I believe this has fixed my ABS issue!