Brains trust help-- Volvo XC90

kazbanz, May 4, 12:54pm
Hey team
Im hoping for some help from the great brains trust.
I have a 2006 Volvo XC90 which is the 2007 model.
Ie Its got the B6324 chain drive engine.
The DASH has fault coming up saying Antiskid service and Brake assist Service.
The scanned Fault code says Position sensor fault.
So far so good
Near as I can tell there is a 3 wire travel switch on the drivers side of the Brake booster and a 5 wire position sensor on the Passenger side.
All the pictures/diagrams ive looked at show these as push in parts from outside the brake booster.
Our auto electrician -(not a Volvo guy) is saying theres a switch/contact inside the booster so the entire booster needs to be changed.
Im scratching my head a bit as a used booster is about $500 yet the two sensors are about $100 (in the uk)
anyone with experience with this issue I'd appreciate feedback

franc123, May 4, 1:45pm
You mean that the fault code is logging in the instrument cluster only? Is it not logging in the EBCM (or ABS if you like) module too? Surely monitoring the live data stream whilst operating the brakes is going to reveal which switch is faulty. What is the actual code?

kazbanz, May 4, 2:23pm
Sorry Franc-I didn't scan but the CODE from scanning comes back as Position Sensor fault. -Sparky is saying you need to replace the entire Booster as the faulty part is inside the booster itself. All the diagrams I can find are saying the travel switch and position sensor are parts that push into the booster.-im trying to picture a part inside the booster being the issue

franc123, May 4, 3:55pm
The fault code must have an actual number, probably beginning with a C.

bigfatmat1, May 5, 2:24am
So unplug sensors one at a time and see which one brings back same code. Cause by the sounds of it you are disagreeing with location of sensor. Surely no one would put a sensor inside the booster that isn't replaceable.

franc123, May 5, 3:48am
RockAuto supplies exchange boosters for that model, seeing that usually means the OE part had been a problem child. It appears there are several position sensors associated with the brake actuation though, really the above process is going to be the only way to be sure.

poppy62, May 5, 3:59am
Hi Kaz! just a simple query of which I'm sure you have checked, is the brake fluid low in the reservoir?

kazbanz, May 5, 4:02am
my thought precisely.

intrade, May 5, 4:34am
volvo is like apple. And i said that before Scanner danner had to programm a new fuse box for from what i recall about that year volvo. because there is a chip inside with programming that cant be changed and is only for that cars vin number. its for theft protection volvo said. The same scumbag as apple is what i was thinking back then. The chip are one time write only and only with factory tool and factory subscription. that fuse box was 1400$ us plus programming plus labour. With a part from a wrack half the system did not work because you cant change the coding.

kazbanz, May 5, 6:08am
Apreciate the thought but definitely isn't the "simple stuff"

poppy62, May 5, 8:53am
I just remembered that I had an issue with a Volvo I had some years ago. It was the brake pedal sensor that is located next to the master cylinder. It was a reasonably common issue but was an easy fix.

kazbanz, May 5, 9:03am
Sounds familiar

tamarillo, Aug 12, 1:40am
My legs itch.
Got as much to do with subject so just saying I told you so.