Ecm-a02b

[jeremycolley]

2005 XC70 AWDSE LUX 167k miles

I have VIDA / Dice, firstly I'd like to thank CheshireD5 (Si Robb) for his excellent service and instructions for installing the software. Buy your kit from him and follow the video on youtube to install it and you'll be fine.

So - I have the Brake Failure stop safely message, ABS light and red ! light.

Codes now read and I have ECM-A02B which Vida suggests is either 'open circuit on the CAN wiring' or 'Defective ABS Control Module'. Having read up on this forum my gut feel is that the ABS (BCM) is faulty and needs repair or replacement. Is this a good place to start investigations, or is there anything else I should check first?

The message came on and went off for a few days and is now on all the time, which suggests some sort of deterioration or intermittent connection - hence my gut feel that it could be dry solder joints in the ABS module.

Thanks in advance

Jeremy

[petey]

I’ve both cut my ABS module open and resoldered the joints (which worked for two years) and then stripped and re-brushed the pump. My suspicion is that the pump was the fault all along, but by reducing the voltage drop across the connections from the pump to the module, I squeaked 20 month’s more time out of it.

VIDA has an ABS process in it, and from memory it ends up with the pump being forced on and you check to see if it actually runs. Mine didn’t, so I took the magnet housing off the pump and found more black dust than on the floor of a black dust factory.
Volvo, BMW, VW group and many more all use the same ATE pump and module. Volvo seem to feel that mounting the rotor in a single bearing at the bottom and a bush at the top is good enough; it isn’t, it leads to a lot of rotor excursion which destroys the brushes. I happened to have a Touareg ABS pump hanging about, so I replaced the brushes on my pump, and fitted the rotor with new bearings and magnet housing from the VW onto mine, and everything’s sorted now.