I Think I Know What This Might Be! (ABS UNIT)

[Luxobarge]

Originally Posted by spottedhaggis

Would this also be the cause for my cruise control not working, absolutely nothing happens when the button is pressed, and I also get the service required warning orange triangle on startup.

I read somewhere that if I start the engine with the clutch in and the service message does not come on it could be this thats the cause, I tested that and sure enough starting with the clutch in it never comes on, it only appears after I release the clutch.

What exact model car and year do you have?

I ask, because on my V70 the service requried light is text, not a yellow triangle.....

[Kecy]

Hi, Would you know where a bout's on the back of the sensor does the O-ring go exactly ?
Thanks in Advance

kecy

Originally Posted by Jaymz

Here you go fella, its a common problem on all 850 and early v70's

here's the fix foryou

http://www.volvoforums.org.uk/showthread.php?t=72655

[buzzy1919]

The step by step instructions were great--fixed my brake position sensor--no more brake assist required or engine service --in the information window--error code PO 573 gone--been almost 3 weeks--thanks again.

[monkeyleader]

Originally Posted by spottedhaggis

Would this also be the cause for my cruise control not working, absolutely nothing happens when the button is pressed, and I also get the service required warning orange triangle on startup.

I read somewhere that if I start the engine with the clutch in and the service message does not come on it could be this thats the cause, I tested that and sure enough starting with the clutch in it never comes on, it only appears after I release the clutch.

Yes. Having trouble shot this in VIDA, I can tell you that any ECM-9000* errors will disable the cruise-control.

Heres an excerpt from VIDA...

Diagnostic trouble code (DTC) information ECM-9000

Condition

The diagnostic trouble code (DTC) is stored if the engine control module (ECM) registers a fault in the circuit for the brake pedal position sensor, the circuit for the stop lamp switch or in the CAN communication between the brake control module (BCM) and the engine control module (ECM).
The diagnostic trouble code (DTC) can be diagnosed when the engine is running.

Substitute value

Cruise control switched off.

Possible source

• Fault in the brake control module (BCM) or the central electronic module (CEM)
• Contact resistance or oxidation in the terminals between the engine control module (ECM) and the stop lamp switch
• Open-circuit in the power supply to the stop lamp switch
• Open-circuit or short-circuit to ground or supply voltage in the cable for the stop lamp switch
• Incorrectly installed stop lamp switch
• Damaged stop lamp switch.

Fault symptom[s]

• Cruise control/Does not engage
• Text window and warning symbol/Text message

[johnboneske]

How do I remove the "C" clip? I see it is in the 3 o'clock position on my S80 and don't know how to remove it??

[goldxc70]

Originally Posted by johnboneske

How do I remove the "C" clip? I see it is in the 3 o'clock position on my S80 and don't know how to remove it??

Push small screwdriver into slot, lever and pull, I believe.
Although having repeated that, I have had no success in getting mine off
This might help: http://www.volvoxc.com/0/resources/h...-replacing.pdf

[MojaveXC70]

My 2001 XC70 cruise control and warning light problems were both solved with a brake pedal sensor repair/replacement.

[MojaveXC70]

I had trouble replacing the sensor until I realized that the metal split ring fits back over the tab that sticks out at the 3 o'clock position, with the split at the 9 o'clock position. Once in place, align the sensor tab with the tab on the housing, and gently but firmly push the sensor back in until it clicks.

(I made the sensor repair carefully, but sadly, in trying to figure out how to reinsert the sensor, the o-ring slipped off and fell somewhere in the engine compartment or the oil pan. Fortunately, someone was selling a pedal sensor with an o-ring online. For $50 I installed it with a comforting click, and on the second test drive the warning disappeared and the cruise control worked again.)

Thanks again to SwedishInside for the clear repair post!

[terry_cunnane]

That's it all complete. I haven’t tested it yet because I am writing this how to whilst the sealant dries. I hope it does work.
I will come back in a few days with another update with my conclusion whether this fix has worked.

So very helpful. Thanks for doing it.

[mrclonkey]

Originally Posted by SwedishInside

This morning I decided to give the sensor an extra piece of protection: Electrical tape (or insulating tape). I did this also for the look. Now my sensor will not stand out as much.

The tape is not dark blue... It is black, but I edited the image to make the tape standout from the black sensor so you could at least see how I wrapped it.

Bl**dy marvellous post!! I used this method on my 2006 V70 2.4 petrol and it seems to have worked. I was getting 'brake assist service required', 'engine system service required' and after a certain number miles a couple of further scary red messages like 'engine system required urgent'. The solder connections and pcb were slightly different and had 3 pins, but I cleaned the carbon tracks and contacts with meths and then carefully resoldered the 3 contacts, avoiding the plastic casing. I reassembled, sealing with transparent soudal fix-all, my incredibly effective choice for fixing and sealing on most jobs these days.
I have a chinese copy VIDA DICE box (£45 on ebay) and software to find and clear fault codes, but for quickness I disconnected the negative battery terminal and held it onto the positive terminal as a system reset. 2 days later, the faults havene't come back and my cruise control works again!!
Thanks a lot