2010 XC90 Auto - loss of acceleration at higher speeds

[NialStewart]

Just reviewing this I've realised I missed a fault code from post #10.

The dealer reported...
ECM-1517 Turbo Control - Pressure too high
ECM-1540 Turbo control - Pressure too high
TCM-0A31 Control module comunication. Signal missing from Engine Control Module (ECM).

And the one I missed...
ECM-1600 Boost pressure seosor - Signal too high.


I presume this is a result of the boost pressure being too high, not because the sensor was knackered.

Nial.

[cheshired5]

In your position I would get back to the car with Dice and Vida then

Diagnostics >Vehicle Communication >ECM (overhead vehicle diagram) >parameters where you can then have up to 10 values running simultaneously.
I'd double click everything throttle, turbo, egr, swirl related and check their values against those in the description tab.

I'd then move to activations and check everything related to the above.

Finally, I'd go to Advanced where you can carry out adaptations of various related motors/modules including the throttle.

The description tab is your friend in all these and tells you what to look for and what is normal.

Somewhere within that is the root of your problem so I'd try to do as much as I can myself before giving up.

[NialStewart]

Originally Posted by cheshired5

In your position I would get back to the car with Dice and Vida then

Diagnostics >Vehicle Communication >ECM (overhead vehicle diagram) >parameters where you can then have up to 10 values running simultaneously.
I'd double click everything throttle, turbo, egr, swirl related and check their values against those in the description tab.

I'd then move to activations and check everything related to the above.

Finally, I'd go to Advanced where you can carry out adaptations of various related motors/modules including the throttle.
The description tab is your friend in all these and tells you what to look for and what is normal.
Somewhere within that is the root of your problem so I'd try to do as much as I can myself before giving up.

One quick question first, what do you mean by "adaptations"?


I'm afraid it's with Volvo and I can't get to it from work, by the time I'm home they're closed.

Clan had posted on a thread about Throttle Position Sensor failures so I PM'd him about this and
he's suggested one of the boost pressure sensors might be the problem. He said he's seen a few
of them go and the diagnostics don't point to this (though one of my original fault codes was
'signal too high').

The dealer it's with isn't a main dealer and I don't think they see many cars through. They're just going
by Vida and I get the feeling they're chasing their tails. They originally thought the turbo might have gone
but have supposedly done enough tests to show it's probably not this, though he was talking about
that again this morning.

I gave them the go-ahead to replace the boost sensor this morning, the guy sounded almost relieved.
I'll report back if this sorts things, if not at least we know it's not this!

Oh fun. :-(

Nial

[cheshired5]

Originally Posted by NialStewart

what do you mean by "adaptations"?

Sometimes things just get out of whack so with adaptions, Vida can activate/manipulate/calibrate all manner of motors to make sure they're moving as they should.

I never change a sensor without testing so hopefully your garage won't and seeing as the boost sensor is easy to test, hopefully the garage also know this otherwise what expertise are you paying £100/hour for?
Anyone can change parts.

[NialStewart]

Originally Posted by cheshired5

I never change a sensor without testing so hopefully your garage won't and seeing as the boost sensor is easy to test, hopefully the garage also know this otherwise what expertise are you paying £100/hour for?

I'm long past wondering!

Although, if the failure is intermittent, as I've seen driving the car...?

I should know by the end of the day, if they can get the part from Glasgow, if this is it or not.

Nial.

[cheshired5]

Your screenshots tell you that the boost sensor is working just fine so a new boost sensor won't fix anything.
You'll just be £200 poorer from parts and labour and no further forward.

If your garage are seeing the same information and decide a new sensor is the fix, change your garage not the sensor.

[NialStewart]

Originally Posted by cheshired5

Your screenshots tell you that the boost sensor is working just fine so a new boost sensor won't fix anything.
You'll just be £200 poorer from parts and labour and no further forward.

Although if the sensor was going faulty in this post....

http://www.volvoforums.org.uk/showpo...7&postcount=17

...it might explain why it is showing full scale boost and the power is down?

[Edit] I think there are 3 pressure systems in the inlet, I'm not sure which one this is[/Edit]

If your garage are seeing the same information and decide a new sensor is the fix, change your garage not the sensor.

We're thinking about it.

Nial.

[cheshired5]

Originally Posted by NialStewart

Although if the sensor was going faulty in this post....

http://www.volvoforums.org.uk/showpo...7&postcount=17

...it might explain why it is showing full scale boost and the power is down?

You would really need fuel pressure data running alongside to help confirm that.
That said, I'm sticking to your MAP sensor being fine. I've seen nothing to suggest otherwise but let's see where you're at after this garage visit.

[colinbos]

Mega Mega help from Simon. You deserve a medal mate.

Respect.

[NialStewart]

Originally Posted by colinbos

Mega Mega help from Simon. You deserve a medal mate.
Respect.

Yep, I'd have been lost without Simon (and Greg's) input.

Drinks on me if you're ever near Edinburgh!