Have I bought a Lemon? Major XC90 problems... help?

angello · Post by **angello** » 08 Sep 2022, 08:33

After a good deal of searching and research we bought a 2010 XC90 Executive in June to replace our aging family car....

Initially, Mrs Angello was very happy - the Volvo had all the toys, was waaaaay nicer to drive than her old nail and seemed to do everything we wanted it to do

Then, the problems started.... We started to notice BLIS system would occassionally not work, or Alarm system would trigger 'Alarm System Service Required' message and a few other issues... inconvenient, but not a major deal breaker....

Then came the breakdown.

Mrs Angello took the Volvo on a trip and rang me to say it seemed to be revving high, there were warning messages popping up on the dash, lights coming on and then while I was on the phone ... the engine died..... on the slip ramp of a dual carriageway...at a roundabout.... with a horse box on the back.... and three kids in the car....

She coasted to the side of the road and there the dead ensemble sat... It would turn over but not start. Cue Police closing road, specialist equine recovery and the whole nine yards.... VERY stressful experience for all concerned.

Having had the car recovered back to our house and rolled into the drive, when I got back from work I put the key in the ignition to see what lights were on the dash and it started instantly ... and drove completely normally. Great

An intermittent fault.

So I now have a car sat on the drive that Mrs Angello won't drive as she can't trust it (I can't argue with that!) that we've owned for 3 months and seems to have some sort of terminal fault that caused the engine to actually stop and shut off...

I've taken it to Volvo to have the codes read and THIS is what has been recorded

What the hell do I do from here? I'm guessing some critical electrical component has some sort of intermittent fault somewhere... but where do I even start? We can't afford to chuck money at this until it's fixed, as we're better to take the hit now and weigh it in than throw another £umpteen thousand at it and still have a car we can't trust...

Help!

Post by **ggleavitt** » 08 Sep 2022, 09:25

First things first. I think I was able to deduce from your codes and your geographic location that you're running a diesel. I'll further guess it's a D5244T5 motor. Please confirm if this is correct.

With this assumption in mind, I see the following active codes:
BCM-0101 (module communication)
ECM-135F (MAF or circuit)
ECM-5720 (module communication)
PHM/PSM (ignore I think)
UEM-0004 (Siren module or UEM circuit)

The alarm module (siren module) is a known problem area with a leaking internal NiCad battery that eats away at the PCB. Replacement is the resolution.
The MAF code needs looked at. VIDA has electrical fault or a failed sensor as probable cause.
Codes for module communication are a little harder to diagnose in granularity but one thing that can contribute to these are a failing vehicle battery or a failing charging system or a combination of both. If the battery in the vehicle is original (Volvo labelled with a week/year installation stamp on the top of one of the terminals), it's 12+ years old and may just be worn out.

I don't see anything that would arbitrarily stop the vehicle from running to be honest, others might see something I'm not.

Were it me, I might troubleshoot the siren module and the MAF after replacing the vehicle battery and validating the charging system, then see where you end up. Battery in this vehicle may be the H7 or the larger H8, either will fit (I installed the larger battery in my '05 when I owned it, just needs the hold-down bracket moved to the right).

Again, probably something I'm missing but this is what I might do were I in your position.

angello · Post by **angello** » 08 Sep 2022, 13:19

Yes, you're right - it's a 5 cylinder diesel.
I know it has a Volvo battery, but I'll check on the date code - good idea.

The reason the engine shut down is the real worry

.... That's seriously dangerous and we were just lucky it didn't get rammed by another vehicle on the dual carriageway before the Police arrived..... That's not a risk I'm prepared to take again.

There were no symptoms of low charge at any point - even after the engine shut off, Mrs Angello was able to crank the engine repeatedly in failed attempts to get it to start so it could be limped off the road... but nothing.... It also started straight up when I got to it a few hours later.

angello · Post by **angello** » 11 Sep 2022, 00:30

Anyone?

AndreyKo · Post by **AndreyKo** » 11 Sep 2022, 08:52

Inspect CEM for moisture. Volvo XC90 has the Achilles' heel in drain under windshield

Post by **abscate** » 20 Sep 2022, 03:57

angello wrote: ↑08 Sep 2022, 13:19 Yes, you're right - it's a 5 cylinder diesel.
I know it has a Volvo battery, but I'll check on the date code - good idea.

The reason the engine shut down is the real worry .... That's seriously dangerous and we were just lucky it didn't get rammed by another vehicle on the dual carriageway before the Police arrived..... That's not a risk I'm prepared to take again.

There were no symptoms of low charge at any point - even after the engine shut off, Mrs Angello was able to crank the engine repeatedly in failed attempts to get it to start so it could be limped off the road... but nothing.... It also started straight up when I got to it a few hours later.

There are many instances of battery sufficient to crank car, but will not run car electronics reliably. Some video of me on a trip with a battery at about 3% of capacity…..

viewtopic.php?t=92161&hilit=Weak+battery+1999

angello · Post by **angello** » 05 Oct 2022, 03:00

One month on and I think we might be making some progress..... Having disgraced itself and been recovered home, the fault disappeared.... We've checked all the things suggested above and drawn a blank, with no smoking guns - battery and charging all good etc.. The car hasn't been driven much as Mrs Angello wasn't prepared to be marooned in it and it's only been used for non-important trips to see if these faults return.

The wretched thing had been largely behaving until the weekend.... when I had a big misfire, a forest of warning lights and several 'failures' - ABS, Transmission, Check Engine light etc. The dash display also dropped the transmission gear display from 'D' to '-' .....

With the fault 'live' I plugged in the OBD and read the multitude of faults, with 'Injector No 2' being the fault causing the misfire and Check Engine light. Engine running, I pulled off the cover and gave the wiring plug on No. 2 injector a wiggle, whereupon it immediately stopped misfiring and smoothed out

..... this also extinguished the ABS and Transmission Fault warnings!

Cycling the ignition cleared all warning lights and the engine then ran as normal.

So I'm now pretty confident that there is a fault in the loom or the plug to No.2 Injector - popping the plug off that injector shows discolouration in comparison to the others which smacks of electrical arcing....

A long test drive this morning saw it run perfectly for a while, then cough a little (as injector began to fault), then illuminate ABS light, change down a few gears in transmission (which I believe is transmission going into 'limp mode' and fixing 3rd gear) and check engine light all came on as power dropped off .... suggesting all those faults appear to be related and kick off from the misfire.

I think this is a replication of the fault Mrs Angello first experienced as it's a pretty close match to the description she gave me in non-mechanical terms of the engine revving high and no power etc. I suspect the engine probably didn't actually 'die' it just lost all power and wouldn't pull beyond limited revs as it was in 'limp' mode.

A bit of Googling has turned up this post:- https://www.volvoforums.org.uk/showthread.php?t=181907 on Volvo Forums which describes pretty much exactly the same fault.

Given all the evidence, I'm going to be investigating the loom to the injectors and replacing the plug on No. 2. Has anyone any experience of dying injector looms? or replacement?

Post by **abscate** » 13 Nov 2022, 06:35

We don’t get the Diesel engine over here in the States but I would inspect all the injector looms carefully. At the least, have some idea as to why #2 faulted.

Post by **RickHaleParker** » 14 Nov 2022, 03:02

angello wrote: ↑05 Oct 2022, 03:00
I pulled off the cover and gave the wiring plug on No. 2 injector a wiggle, whereupon it immediately stopped misfiring and smoothed out ..... this also extinguished the ABS and Transmission Fault warnings!

Before you dump a load of time and money into it. Clean the connectors and tighten them up with a pair of needle nose pliers or a small screwdriver.

They may not look very dirty but just a thin layer of oxide is enough to cause poor electrical connections.

I just picked up a non-working first generation Bose Wave for $8.00. Took it home open it up, cleaned all the electrical connectors and it rose from the dead. Got me a $100.00 Bose Wave for $8.00 and it sounds great

angello · Post by **angello** » 15 Nov 2022, 14:03

A month on, an update.....
Having cleaned and tweaked the plug for injector No.2 it's been back together and behaving perfectly since October... so I'm calling it problem fixed.

Phew!

I got very close to just getting out of this car as the barrage of faults it displayed had big $$ written all over it - even Volvo themselves didn't know where to start and were looking at just replacing parts....

Turns out it was just a poor connection on No.2 injector plug. This must have been feeding back into the CANBUS and disrupting communication between all modules and firing random fault codes for all sorts of things that actually aren't faulty. Not an easy one to diagnose and worth checking if anyone else gets something similar.