V50 2.0d limp mode - exasperation sets in ....

[Penrynian]

I’d like to ask opinions about way forward with this please. It’s “one of those sagas” so I’ll try to keep it brief ….

’08 V50 2.0d R-design, no DPF fitted in this model, it has what they call a standard Ford/Citroen/Peugeot lump installed.

Last year was an expensive year - had a new turbo followed by a new clutch. The new turbo increased the output power such that it showed up the fact that the clutch was slipping which hadn’t been previously noticed.

Recently been getting intermittent limp mode, no EM light on the dashboard, just wouldn’t rev above 2500.

Last week we entered permanent limp mode, decided to take it to main dealer for code read and “adjustment of pin tensions”.

Had quite a few DTCs before, left with only two afterwards but they were deemed to be related to starting issues, which I don’t have. “Bear them in mind if it happens again” was the suggestion.

CEM-3A00 ECM, software faulty signal
ECM-C301 control module, faulty software checksum ECM

Drove away from the garage £300 lighter but the car went light poo off a spade.

The euphoria lasted less than 24 hours, we’re now back to intermittent limp mode.

Taking it back next week for a “complimentary code read” and a chat about a way forward.

What is most irritating is the “change some modules until you get the right one” approach.

For all the internal software and well-trained technicians to interpret the error messages, it’s still a hit and miss affair. CEM is allegedly c £1300 but no guarantees it’s fix the fault if changed.

Any comments welcomed.

[Bungo]

Has the car had a remap or been tweaked ?
If not test alternator and battery.

[Penrynian]

Originally Posted by Bungo

Has the car had a remap or been tweaked ?
If not test alternator and battery.

I have had it nearly 3 years Bungo, and I haven't had it re-mapped.
Can't speak for the previous 2 owners.
When it goes into the Volvo garage for code checking on Tuesday I'll ask about the status of the code - presume they could tell with diag machine plugged in?

Had a new battery about 2.5 years ago - it had classic non-starting problems that were fixed by throttle body cleaning and chamfering of the vane.
Funny you mention that though, because one comment made after they checked pin tensioning was that the remaining two DTCs refer to potential starting issues. Yet it never fails to start.

[Penrynian]

An update - by a stroke of luck I was introduced to an independent garage, called Powells in Redruth. They have an ex Volvo master technician on the staff so I put it in for code read/inspection/opinion about why it goes into limp mode with no engine management light on the dash.

They found P2263 fault code - "boost pressure outside parameters".
Found turbocharger actuator arm was disconnected from the turbo.
Also main turbo-to-exhaust fixing was insecure.

Action taken: refit actuator arm using replacement E-clip (about a fiver) and remove, re-position and refit turbo securing clamp.

Result: it drives better than it has done in 2 years.
Just done 200 miles today from SW Cornwall to N Devon, round trip. Didn't miss a beat.

Chuffed that Powells did all this for well under £200.

And not so chuffed that Volvo main dealer in Truro charged £300 for checking and adjusting pin tensions that made no difference whatsoever, and ultimately advised to "change the ECM (£1200) and see what happens".

[Bloders2]

Originally Posted by Penrynian

An update - by a stroke of luck I was introduced to an independent garage, called Powells in Redruth. They have an ex Volvo master technician on the staff so I put it in for code read/inspection/opinion about why it goes into limp mode with no engine management light on the dash.

They found P2263 fault code - "boost pressure outside parameters".
Found turbocharger actuator arm was disconnected from the turbo.
Also main turbo-to-exhaust fixing was insecure.

Action taken: refit actuator arm using replacement E-clip (about a fiver) and remove, re-position and refit turbo securing clamp.

Result: it drives better than it has done in 2 years.
Just done 200 miles today from SW Cornwall to N Devon, round trip. Didn't miss a beat.

Chuffed that Powells did all this for well under £200.

And not so chuffed that Volvo main dealer in Truro charged £300 for checking and adjusting pin tensions that made no difference whatsoever, and ultimately advised to "change the ECM (£1200) and see what happens".

sorry, what are "pin tensions"?
Personally, id write a letter to the Volvo dealer and explain what the problem was and who found it. Id then ask for at least a partial refund as they should be better qualified and trained than an independant.
You will probably get nothing back, but you only know if you try. It will also convey to them they are not up to the standard required.

[Penrynian]

Pin tension checks are wiring continuity checks - there were so many seemingly disparate and unrelated faults coming up that it was deemed unlikely that all the suspected modules were actually faulty. So it was assumed that there was a fault with the interconnecting wiring somewhere, i.e a common factor that affects all.

This all came about from a code-read; it would seem that diagnoses are only made by looking at a computer readout, not by aiming an Eyeball Mk1 at the engine bay.