ABS pump - which caliper, which pipe?

[ShakTak]

I’ve just got VIDA and read the fault codes due to an intermittent ANTI SKID message.

It’s come up with the brake pressure sensor (BCM-0130). I’ve worked out which one of the two sensors it is by testing.

My question is, when I replace it, air will get it the system so I want to bleed it.

It looks like I should only have to bleed two calipers, so do I follow the two thinner pipes directly under the larger pipe (with sensor on) that enters the pump?

As I can’t see inside the pump, I have no idea if my guess is right!

Maybe someone knows for sure. Thanks.

[gmonag]

Have you eliminated other possible causes?

Possible source

-Open-circuit in the wiring
-Short-circuit to ground or supply voltage in the wiring
-Defective pressure sensor
-Internal fault in the control module.

Make sure the sensor is faulty before replacing it.

[ShakTak]

Well that’s straight from VIDA.

Back to the question please.

[Chunk11]

Not sure which two you will have to bleed but if you need to bleed 2 then why not bleed 4 and do a full brake fluid change as you will be half way there already.

[ShakTak]

Originally Posted by Chunk11

Not sure which two you will have to bleed but if you need to bleed 2 then why not bleed 4 and do a full brake fluid change as you will be half way there already.

Just replaced rear discs a few days ago and did the whole system before my VIDA arrived, so was unaware of the fault.

Back to the question please. 😆

[Dastardly Diesel]

Originally Posted by gmonag

Have you eliminated other possible causes?

Possible source

-Open-circuit in the wiring
-Short-circuit to ground or supply voltage in the wiring
-Defective pressure sensor
-Internal fault in the control module.

Make sure the sensor is faulty before replacing it.

Indeed. VIDA can't tell the difference between a faulty sensor, and a failure somewhere else on the same 'circuit' that gives the same end result.

I believe VIDA allows you to cycle the ABS pump to bleed it, and you'll need to bleed the brakes too. Do all 4, starting with the corner furthest from the master cylinder and working inwards. You can't effectively bleed just the one circuit. As per above, considering that ypure doing it anyway it's not really any extra labour to do the fluid at the same time.

[gmonag]

Originally Posted by ShakTak

Well that’s straight from VIDA.

Back to the question please.

Yes, bleed the brakes. All of them. Like you would in any other situation that requires bleeding.

I still say you need to properly diagnose the fault.

[Tannaton]

Ok to back to the question -

Why don't you remove the ABS module and strip it down - then when you inspect you and identify the through route and you will know for sure if you only need to bleed 2 calipers?

[ShakTak]

Originally Posted by Tannaton

Ok to back to the question -

Why don't you remove the ABS module and strip it down - then when you inspect you and identify the through route and you will know for sure if you only need to bleed 2 calipers?

That’s the point of the question in the first place, to see if anybody had an answer.

I’ll just bleed everything again, as mentioned it’s not a big deal. Thanks anyway.

[ShakTak]

Useful link, this is for the P1 platform though, not the P2 which is in question.

https://www.volvoclub.org.uk/tech/S40MY2005-Brakes.pdf