Brakes: List of DTC's to work through....

[currymunster]

Finally got Vida (Thanks Simon&#128077
And pulled some codes.
Anti skid service required on 2004 XC90 manual.
About 34 codes, some active and some not.
I want to concentrate on the brakes for now so looking for the best procedure so I don't waste time and more importantly money.
BCM-0133 sensor signal low
BCM-0148 communication error
BCM-0131 left rear sensor faulty signal
BCM-0132 left rear sensor mechanical error
BCM-0136 pressure sensor 1 & 2 outside range
After this it will be ECM but this is more important.
Just looking to see if anyone know if one fault can cause all those issues or where the best place to start is.
Thanks 👍👍

[paddy74]

First of all, you should erase the DTCs and than run the car around the block (at least over 20mph and more than 500 meter) and read the codes again. That should eliminate a few and gives a clearer view.

After that post all the codes again, not only specific to one module.

If the BCM errors still stand, I'd start with the most obvious things: the rear sensor on the left. It is behind the wheel bearing, check from underneath. Maybe there is something obvious like a corroded cable/plug.

The pressure sensors are interchangeable, so try to change the plugs and see, if the error changes in any way (work -> erase DTCs -> run the car -> readout again).

[currymunster]

Originally Posted by paddy74

First of all, you should erase the DTCs and than run the car around the block (at least over 20mph and more than 500 meter) and read the codes again. That should eliminate a few and gives a clearer view.

After that post all the codes again, not only specific to one module.

If the BCM errors still stand, I'd start with the most obvious things: the rear sensor on the left. It is behind the wheel bearing, check from underneath. Maybe there is something obvious like a corroded cable/plug.

The pressure sensors are interchangeable, so try to change the plugs and see, if the error changes in any way (work -> erase DTCs -> run the car -> readout again).

Thanks,
I can't drive it at present due to a broken clip on the rear off side brake shoe. I need to get a new back plate as the clip retainer head been snapped off by someone.
I've only just bought the car. Well, back in August but it's been stood idle. It now needs a new battery as well.
I have a print out which I will attach one I've made the file size smaller.

[paddy74]

Then start with the battery. A little drop of power, and some modules produce crazy results and errors. So first thing should be to get a working battery, idealy in good to very good condition.

If you can't drive, nevertheless erase the errors and read it out again. Some will likely disapear, because some things need movement to get tested (parts of the brake eg).

I'd then repair the known fault on the brake shoe. While you are there, you can easily check the sensor that's listed.
Check the wheel bearing as well, in contrary to the front, the reluctor ring is part of the bearing, so faults there can easily extend to the sensor. Sometimes a "broken" cv joint and the grease coming from it can also disturb the sensor.

[currymunster]

Originally Posted by paddy74

Then start with the battery. A little drop of power, and some modules produce crazy results and errors. So first thing should be to get a working battery, idealy in good to very good condition.

If you can't drive, nevertheless erase the errors and read it out again. Some will likely disapear, because some things need movement to get tested (parts of the brake eg).

I'd then repair the known fault on the brake shoe. While you are there, you can easily check the sensor that's listed.
Check the wheel bearing as well, in contrary to the front, the reluctor ring is part of the bearing, so faults there can easily extend to the sensor. Sometimes a "broken" cv joint and the grease coming from it can also disturb the sensor.

I've ordered the back plate and shoes with fitting kit.
Looking at the VIDA parts diagrams it looks like the front axle has reluctor rings but the rear doesn't.
It obviously had sensors at the rear as you've mentioned cleaning them.
If there is no reluctors on the rear then how do they work?

[paddy74]

Originally Posted by currymunster

I've ordered the back plate and shoes with fitting kit.
Looking at the VIDA parts diagrams it looks like the front axle has reluctor rings but the rear doesn't.
It obviously had sensors at the rear as you've mentioned cleaning them.
If there is no reluctors on the rear then how do they work?

For the rear, the "reluctor ring" is already integrated into the wheel bearing.

Take a look at the second picture, that's the back side. The four white whatever-they-are-called...
https://www.skandix.de/en/spare-part...right/1014995/

[currymunster]

Originally Posted by paddy74

For the rear, the "reluctor ring" is already integrated into the wheel bearing.

Take a look at the second picture, that's the back side. The four white whatever-they-are-called...
https://www.skandix.de/en/spare-part...right/1014995/

Great picture thanks. That clears up my confusion.
I know what I'm looking at now when I remove it all to clean now.
Once the back plate turns up from Wales.....

[currymunster]

Back plate turned up and apart from some minor problems it's all back together but the parking brake still doesn't work.
I've adjusted the same as Vida but it still isn't right.
I even bought some of those adjusters but they don't fit.
They were sold for a XC90 but they are to fat to fit in the recess on the shoe which means I can't get the drum on.
Does it need them? Is there something else I'm missing or should be checking?

Minor issues were caliper bolts rounded off before I even started.
Off side ABS sensor looks like once in its life it hasn't been tightened up properly and the drive shaft has worn it down.
Off side back plate needs doing in the future. The bottom shoe had worn through it and more there is a small hole.
Joy.

[currymunster]

Originally Posted by paddy74

For the rear, the "reluctor ring" is already integrated into the wheel bearing.

Take a look at the second picture, that's the back side. The four white whatever-they-are-called...
https://www.skandix.de/en/spare-part...right/1014995/

Hi, parts turned up and the parking brake is working fine. Surprisingly easy to adjust..
New battery fitted and codes deleted.
Took it for a spin and the read the codes.
Here's what VIDA spat out at me below.
Obviously the brake pressure sensor needs doing and I assume that is the reason for the anti skid service message.
I already have the part. It turned up today.
The next one is the brake pedal position sensor.
What I really don't understand is all the "Faulty communication"
How do I go about fixing those?

[SwissXC90]

It is extremely unlikely that you have multiple bus failures at the same time in different places in the vehicle.

The common point for all the CAN buses is the CEM.

If all those comms messages continuously come back, then you need to remove and inspect the CEM for water damage and corrosion on the connectors.

Don't bother with any other faults until you fix the bad comms problems.