V50 General : Speed sensor faulty reading trough OBD2 - how come?

[LizardOfBodom]

Hi everybody

A while ago I was writing about weird behaviour of my car that ocasionally goes into "dull mode" and does violent jerking while decelerating.

Problems still persists and occurs more often now, BUT yesterday I made an important discovery. I was driving with OBD reader and torque app active with realtime monitoring of data, and when it started happening again (car became dull and started to jerk on deccelerating) I noticed the speed was showing 0 on the screen. Please see screenshot attached. Speed on speedometer was showing correct values in that time.
Whats more - I did a readout of faults and it show a pending error: P0501 Powertrain - Vehicle Speed Sensor Range/Performance. Still driving, I cleared it using torque and car imediately regained full power and jerking have stopped! Also, speed on torque app was reported correctly and showing actual car's speed!

This was huge, I'm really happy I found anything on this issue, but now a big ask for help to you - what is the problem? What sensor would be responsible for not reporting correct values to ECU but reporting correctly on dashboard?

will appreciate ANY suggestions, thank you very much!

[cheshired5]

Start with these simple checks.
https://www.youtube.com/watch?v=77sntnVpyvI

[LizardOfBodom]

Originally Posted by cheshired5

Start with these simple checks.
https://www.youtube.com/watch?v=77sntnVpyvI

Will do tomorrow, thanks, easy to check.

Although I must add I have never had TC/ABS light on, nor have ever felt it disabled.
Also - does the same sensors report speed to dashboard or those are only for ABS purposes, do you know maybe?

[cheshired5]

A cracked or corroded ring can be bad enough to create a logged fault without noticeably affecting the speedo readout so see how they look first then take it from there.
You may need better diagnostics though if the problem isn't obvious asTorque Pro can be of limited use in situations like this.

[LizardOfBodom]

Originally Posted by cheshired5

A cracked or corroded ring can be bad enough to create a logged fault without noticeably affecting the speedo readout so see how they look first then take it from there.
You may need better diagnostics though if the problem isn't obvious asTorque Pro can be of limited use in situations like this.

Hi

I have checked as per your YT link, everything seem to be ok just from close inspection. Do you reckon I need to disassemble wheel hub to properly see those rings? If not, what else would you recommend me to do? Any way to check the actual sensor that reads from those rings or is that interconnected?

I had a big diagnostic reader plugged in at my local indie worhshop, but it came up with nothing else except the same fault code :/
Would Volvo dealer with VADIS come back with pinpoint location of the fault or its gonna be same story - generic fault + "we need to replace half of the car and see what will help" ?

[cheshired5]

Vida will be able to tell you what you need, even individual wheel speeds.
I sell the complete setup which many members have bought but I also read cars for free.

I would do a separate request thread for a read using Vida and I'm sure a member in your area will oblige...... Not everyone is free, though most are.

[LizardOfBodom]

Originally Posted by cheshired5

Vida will be able to tell you what you need, even individual wheel speeds.
I sell the complete setup which many members have bought but I also read cars for free.

I would do a separate request thread for a read using Vida and I'm sure a member in your area will oblige...... Not everyone is free, though most are.

Im in Ireland, Dublin/Meath, not many people on this forum from here :]
Was considering investing in VIDA/DICE, have found few on Ebay but wasnt convinced. But it would cost me same as "diagnose" in stealership so I might reconsider though.
Can you PM me with the price for your kit please?
[EDIT: nevermind, found your post with price and explanation :]

Wheel speed sensor aside, any other suggestions as for culprit of this issue, anybody? :]

[cheshired5]

Originally Posted by LizardOfBodom

Was considering investing in VIDA/DICE....... But it would cost me same as "diagnose" in stealership

It wouldn't because you still have a Dice unit at the end which you can sell.
The money paid to a dealer is dead.

[LizardOfBodom]

Originally Posted by cheshired5

It wouldn't because you still have a Dice unit at the end which you can sell.
The money paid to a dealer is dead.

no no, I was actually saying it as a "pro buy" argument, sorry, english is my 2nd language :]

[cheshired5]

Originally Posted by LizardOfBodom

no no, I was actually saying it as a "pro buy" argument, sorry, english is my 2nd language :]

I understand what you mean now.
A couple of members in the Republic have bought Dice from me and others have it too so still put out a request. You may get lucky.