Just when you think all is sorted - A3 (ABS) fault code 443

[JohnM 855 T5R]

Hi All,

After a drive in the T-5R on Sunday to keep the battery topped up, the ABS and TRACS lights came on. Read the codes just now and it's giving me:

443 - Electrical or Mechanical fault in hydraulic modulator pump motor.

That's the worst case code really as it could mean a replacement ABS pump unit if that's had a major failure. Has anyone had this problem and what "fixes" are there (apart from a new unit)?

Thanks
John

[DaveNP]

It doesn't sound like the typical symptoms but have you considered the common problem of 'dry' solder joints in the ABS controller? with a broken connection in there it could throw up a false fault code.

I can empathise with 'Just when you think it's sorted', I've just replaced both wishbones, ARB droplinks, a steering rack gaiter and a CV joint boot on mine for the MOT, took too long as I had problems getting parts and working in the snow etc. The CV boot was stretchy one but in cleaning the crap away before trying to fit it I must have brushed too hard at the ABS reluctor ring and brushed away a rusty tooth as the ABS now fires every time between 20 and 10 mph, at least all the nuts and bolts should come undone easier this time round

[JohnM 855 T5R]

Originally Posted by DaveNP

It doesn't sound like the typical symptoms but have you considered the common problem of 'dry' solder joints in the ABS controller? with a broken connection in there it could throw up a false fault code.

Hi Dave, I've just read of dry solder joints as a possible cause of this problem, so good call,

I'm going to go through the system from fusebox through to pump and check fuses, clean all connectors of the control module and the modulator/pump unit and see where that gets me.
If its a dry joint in the control unit, that should be easy enough to fix but if its in the modulator unit I guess it will have to be taken out to inspect and fix if necessary. Or can it be done in situ - anyone know?

Regards
John

[DaveNP]

If it is a 'dry' joint (emphasis on if) a possible quick bodge fix is to wedge something like a bit of card between the plug and the unit to push the plug to one side, the 'dry' joint is actually where the solder has cracked which occurs mostly where the pins for the plug fit into the circuit board, pushing the plug to the side pushes those cracks back closed. As I say it's all a bodge but for me it meant I could drive for a couple of weeks without a code. Fixing the dry joints requires splitting the module box open which I did in a brutal manner but you do need to remove the control module box from the car, no need to remove the pump unit and brake lines as it can be unbolted from the pump unit relatively easily.

[Cookeh]

Sounds like damaged/missing insulation on the pump power wires to me (the two wires running from under the top of the black casing into the ABS module connector). The wiring here often deterioates, leading to shorts.

[Monty rudge]

Hi i had similar problems with c70 and traced it to pump motor. Removed pump motor and took it a part cleaned inside of gunge and reassembled it works fine. Important point when removing pump from abs module be very careful.

[JohnM 855 T5R]

Thanks for suggestions so far. I'll be following up on these over the next week. Meanwhile, if anyone else has ideas or experience of this problem, please keep on posting.

John

[attilat5]

Hi John

Sorry to bring up an old thread but wondered if you managed to resolve your abs error code issue?

My abs and tracs light came on and I did a scan and it came up with the same DTC as you.

Hoping its just dry solder joints.

[JohnM 855 T5R]

Originally Posted by attilat5

Hi John

Sorry to bring up an old thread but wondered if you managed to resolve your abs error code issue?

My abs and tracs light came on and I did a scan and it came up with the same DTC as you.

Hoping its just dry solder joints.

Yes, I resolved it - an easy fix. Turned out to be two simple issues. The earth strap at the back of the engine was loose so tightened it up. And whilst I was at it, I cleaned all the pins on the main multipin ABS connector using switch cleaner and "air in a can". Bingo, all was well again and has been ever since.

The 850 doesn't suffer the dry joint problem to any great degree (though it can happen rarely). It's the s/v70's that have this problem. The ABS unit changed and it's this later one that suffers the most.

Regards
John

[attilat5]

Very helpful and glad to hear you got it sorted!