[gezaphoto]

About month ago the girlfriend was driving home on a Friday night and had #4 coil pack fail. I wasn't too surprised as the XC90 (146K miles) was due for a new set and new plugs but a pain none the less. Needing all the cars on the road for the week (two teens driving and the GF in nursing school) my only option was aftermarket coils, either DuraLast or Import Direct from O'Reilly.

I went with the Import Direct after reading on here they might be reboxed Volvo oem, unfortunately they are not. Went with Bosch Iridium plugs since that's all I could get over the weekend to have the car on the road monday morning.

Install went fine, I had to replace the fuse as well, no errors to speak of and the car drives great. Then a day later I get the CEL and dreaded P0420 and P0430 catalyst codes. I read through a million threads on the error so I am starting basic -> to $$ repairs. I cleaned the MAF, did a PCV glove test, checked for vacuum leaks, cleared the codes once, drove 45+ minutes on the highway to hopefully burn anything in the cat out and just cleared the codes again today. Oil change and new air filter a week or two before the coil pack went, I've been running full Castrol synthetic since I bought the car 5 years ago.

I'm adding some Jectron to the tank today and we'll see if the codes stay cleared.

Questions:

Would the Bosch plugs throw this error code? I was under the impression that the Bosch Iridiums would be fine, although I do know how finicky Volvos can be about plugs.

I am about to order a new thermostat and PCV as maintenance items, anything aftermarket OK for this or stick with genuine Volvo? Dorman PCV is less than half the cost but I can't find any Volvo specific reviews, not sure about what aftermarket T stat would last (Mahle, rein?).

Is there a good way to test the upstream o2 sensors? I have VIDA and a dice unit but just starting to get acquainted with it.

Will aftermarket o2 sensors function or am I biting the bullet and spending $260+ on each one?

 

[ChitownV]

First, the glove test is for the 2.5t engines, not the 3.2.

Second, have you replaced the cheap aftermarket coil with a good branded one? I am not sure where you got that Import Direct is a reboxed Volvo coil for the 3.2. The other coils may be on their way out too.

Third, Have you replaced all spark plugs with recommended plugs outlined in this forum?

Fourth, have you used a good scanner or VIDA to see if there are any misfire codes stored? This could indicate additional issues with other cylinders.

Fifth, it is talked about here Not to get the cheap Dorman part. You have to pop off the circular cover, often times cracking the plastic as seen in many many other makes with a diaphragm PCV/CCV. It doesn’t last and the cover can leak.

Lastly, IMHO, you have to stop piece-mealing maintenance/repairs and stop going cheap. Do it right once and that will prevent parts going bad early as well as getting other issues due to premature failure or poor performing cheap parts. Do the maintenance right and actually do your maintenance as outlined in the 3.2 sticky thread. What is your mileage.

 

[gezaphoto]

I thought the glove text applied to all of the Volvos, good to know it is only for the 2.5. Is there a similar test for the 3.2?

Yes, I have VIDA and scanned, no other misfires or issues other than when the coil went and the P0420/0430. I was out of luck going aftermarket with the coils, happened on a Friday night and I had no options for genuine Volvo as the car had to be on the road Monday morning. It got a full set of coils and Bosch iridium plugs, could not get Densos for almost a week at that time.

To clarify I am replacing with a full PCV, not just the diaphragm, I normally use genuine Volvo unless there isn't an option (ie coils) or if it's verified an aftermarket part is good/better which is why I asked about the parts. Mileage as stated above is 146K, so it is ready for coils/plugs/pcv/waterpump etc. It's been a matter of having the time to do the maintenance with 3 kids in school/sports, 2 of them teens driving the other cars and the girlfriend in nursing school. Now that she's done I will be able to keep one vehicle home for maintenance this month.

Densos and Volvo PCV on order for this weekend, water pump/coolant system refresh will have to happen after - will most likely order the FCP kit plus the decoupler pulley.

 

[ChitownV]

Ahh, much clearer and great you have a good general understanding of the XC90 3.2 as well as VIDA. The PCV is a little more difficult to determine if it's bad. If it is really bad, like completely torn diaphragm, then you will hear the whistle and vacuum. If it is a smaller tear, leak, etc., it can be more difficult to determine. But at your mileage, sounds like you already know to change it that part for maintenance.

Still trying to summarize,

• after the coil issue, you bought a whole set of coils, but they are the cheaper ones
• you will get the entire PCV. On FCP, if they have an OE/M option, then get that as it can be cheaper than Volvo branded. The Dorman is not OEM and there is a reason it's much cheaper.
• you did all plugs with Bosch Iridium and plan to keep it
• you plan to do the coolant system, serpentine, decouple some time soon

Now about a month after changing all coils with cheaper aftermarket and changing plugs with Bosch Iridium, you get the P0420/P430 codes.

Are you consuming any oil?
What oil change intervals are you using? 5k, 7k?
Any other maintenance before this or was there basically no other engine maintenance besides oil/filter & air filter? Maybe plugs around 75k miles?

Btw, an XC90 member in Europe and on several German forums, Castrol synthetic oil is reported to carbon up more and leave more varnish on engine internals than other good synthetic brands like Mobil 1, Pennzoil, Liqui Moly, and Royal Purple.

 

[gezaphoto]

Full set of coils as "cheap" insurance knowing when one goes the others could fail. #4 coil had failed, and cracked/melted. Whatever they are filled with smells horrible.
Set of plugs as that would rule out any fouled plug issues, the old ones weren't too bad aside from one (#6 if I remember, I have to go though my phone pics), gaps were a little off.
P0420/0430 showed up in a day after the coils/plugs and about a month after the oil change. Again this was done as it was the only coils/plugs I could get and install by Sunday and I didn't want to risk another misfire/coil failure.

At this point I only had the car soft OBD II tool, I was in the process of setting up VIDA (ebay copy that wouldn't work with DICE) and waiting on the DICE unit from AliExpress. Once I got Roxanna's VIDA I read all the codes and then cleared them a couple days after they P0420 showed up to see what would pop back up. The 0420/0430 showed back up within a day (15 miles of driving I believe)

The car was purchased CPO from the local dealer, all scheduled maintenance was done by them up until the warranty ran out at 100K. IIRC it had new coolant, plugs and some other preventative stuff done as part of the sale, I have to go dig up the paperwork.

Oil changes have been mostly at the 7500 recommended intervals, I say mostly because I typically change in the spring after lots of short trip (school) driving and prior to summer road trips. Oil consumption has been maybe a 1/2 qt per change? I think this last one was closer to a quart total but I went over the interval a bit and we had done a long trip with trailer in tow so not surprised. Planning on the next change at 150K and probably sticking at a 5K from here on out.

No other real engine maintenance - coils/plugs and coolant/pump/t stat etc. are all on my to do list pre 150K. I have been using the Castrol synthetic as rec but I am not opposed to running something different/better in my cars. I also ordered a set of the Delphi coils, hate spending the money twice but the car made it through high school and nursing school finals and that pays for itself!

 

[ChitownV]

Volvo dealership maintenance can ruin an XC90.

Volvo scheduled maintenance up to 100k miles is nothing more than oil/filter changes, spark plugs ~70k miles, air filter, and any fluids or additives they can upsell. That's it and that's been a trending problem.

Oil changes at dealership 7,500 miles is also another issue. Dealership doesn't usually use full synthetic unless requested. It should be done closer to 5k miles and use full synthetic.

Many 3.2s have a lack of maintenance issue and it seems yours does too. I specifically write in the stickied 3.2 thread to do most of the engine maintenance around 100k miles while Volvo says 150k miles. Volvo also says their transmissions are lifetime fluid, which we know is not.

Some thing outlined with explanations in the stickied 3.2 thread,

• Do 5k mile oil changes and try Mobil 1 0W-40
• Catch up on the engine maintenance and preventative fixes
• Check your exhaust for rust, especially the downpipe and flex pipe areas. A link to Ryan R's thread fixing his rusted-with-holes downpipe/secondary cats worked for him and P0420 codes
• There are more discussions about P0420 in the 3.2 thread such as, you may have carboned up piston rings due to the dealership oil changes, oil consumption could be caused from things like the PCV to the piston rings, oil consumption could damage the catalytics

 

[Hong Kong]

"Btw, an XC90 member in Europe and on several German forums, Castrol synthetic oil is reported to carbon up more and leave more varnish on engine internals than other good synthetic brands like Mobil 1, Pennzoil, Liqui Moly, and Royal Purple."

Yes Im from EU and first 6 years of new car I used Castrol that filled deposits in PCV and clodgged all very bad. Glove test was blowing like baloons. Of course 2.5t 2006 xc90. Just soon after 5 years my turbine blow white smoke that all area past summer without mosquitos hahaha
I dont like cheap gipsy stingy chinese parts and even if i was at begining against Volvo exchange parts that Volvo repair old used not yours and sell under "exchange" way one is bevel gear exchanged and also turbine that i purchased. Now after 10 years bevel gear is dry no signs of leak and as well turbine.
I changed all PCV parts with original Volvo and from than using Mobil 5W50 regular change every max 9000 km.

Inspected with camera inside opened PCV pipes ect its clean after 85000 km.
Need to add that after I changed PCV parts car spooling incredible better.

Why Mobil 5W50 on my engine? After 180.000 km i start using it and I drive very fast and temperament that in US isnt possible. Mobil 5w50 i start using after 180k km as thicker oil and caracteristics for cooling turbine with my style of driving...where average on highways is 160km/h and when free even more to burn deposits.

Engine now have 16 y. and 355.500 km and thicker oil I use. Consumption of oil on 2.5t by factory is normal and its not so much lets say in 2000 km approx. 0,2 - 0,3 dcl but i think as laik its still acceptable. Or?

Dont use Castrol as create huge deposits inside engine if you want to see photos first 6 y and after that I clean engine with Engine flush liquid...placed cheap 5,5 liter with and run 50 km high speed high rev...and drain... Never again Castrol-a Lola Oil

Mobil i tested now 10 years and trust me no sign of deposits like before.
All proved with photos and my test.

Bear in mind 2.5t engine is low pressure turbo and need good cooling oil.

All of my photos of repairs you can find under my posts here im member from 2006.

 

[RyanR]

Never discount that you could have two problems and not a "cause and effect" situation. 146K is well within the age for the flex pipes to start failing. As the fex pipes are in between the upstream and downstream sensors on both banks, this will give you p0420/p0430 codes. Get an ELM OBDII dongle and Torque Pro (or similar) for your phone. Try to see how "permanent" these codes are.

Also, I'd not use mystery brand parts. Use Bosch/Denso/NGK. I'd hit the salvage yard before getting no-name coils.

-Ryan

 

[gezaphoto]

Finally have a chance to update my repair/maintenance adventures here, school got out, I got really busy with work and then caught some nasty cold (not covid) that laid me out.

A bunch of work has been done with a road trip on the horizon so I will try to break this down chronologically - the P0420 issues may be the least of them now.

Plugs, coils, pcv - done
Full water pump, belt, tensioner, decoupler pulley, t-stat, upper/lower hoses, reservoir done (thanks @RyanR for the rambling video, it helped!)
SAS/clock spring clean - done and may have created massive issues for another thread
transmission flush - to do ASAP (first one was done a year ago)
Mobil 1 oil change - to do as soon as I can get another jug of 0w40

Thanks for the input on the Mobil 1, I ordered two 5 qt jugs early June, only one has been delivered after getting a "running late" message, and the next order looks like I stumbled into an amazon shipping scam, money is refunded and magically received one jug from walmart (who I did not order from). Haven't found 0w40 locally yet.

Way back on 5/14 I did the new plugs, coils and eventually the PCV.

I took my time, checked the plug gap coming out and going in and vacuumed out each cylinder with my rigged up needle nose blower attachment on my shop vac.

#4 still had some crud from the coil melting/oozing whatever is inside them so I plugged up the hole and spent a good 30 minutes making it shiny again. I had received an email that the PCV shipment was delayed until the following week so I put everything back in the vehicle, rolled up all my tools and got cleaned up - only for the PCV to get delivered! So back to wrenching and cleaning.

I plugged up any of the holes and used brake parts cleaner and a plastic scraper to get as much of the oil deposits off as I could. Vacuumed and wiped it down and installed the PCV. So much easier than the 5 cylinder engines. I cleared the codes and the next day took it up to a Rays game in St Pete, about 30 miles each way, good mix of highway and stop and go. Codes popped back up in 15 miles or so.

The next weekend I had to pick up family from the airport and I had run through my tank of gas with Jectron, erased all the codes with VIDA, filled up with premium at WaWa - a cool $100 - and drove up to TPA - just shy of 100 miles round trip. NO CODES!! I thought I had finally done it, the car was peppy and smooth, new plugs and coils with premium was a sweet ride.

Fast forward to Monday and the GF takes the car to work, 26 miles of around town driving and the codes reset, CEL on. Still scratching my head, so next item on the list - coolant system/belt etc. And the SAS....

 

[gezaphoto]

Back to current time - All the parts for a full water pump/idler/decoupler/belt service arrived, I wasn't wrenching on Father's Day so I took Monday off to tackle it. RyanR's video with coffee in the morning and then sweating my ass off in FL heat, luckily I have a tent so it helped, and saved me from the impending downpours. The water pump is tight fit, lots of cuts and scrapes from getting my hands in there, and even dropped a torx bit behind the oil cooler. Thankfully it fell to the "easy" side and I retrieved it in seconds.

Note for others: The old radiator hoses are a bear to remove, especially the upper to the t-stat buy the replacements in case you have to pry/break/cut them off. Much easier to access the far side bolts on the t-stat if you aren't removing the manifold.

The job is pretty straight forward as Ryan has mentioned, definitely a bit tedious at times, the damn PS reservoir will make you mad. I used a metal rod to prop up the AC compressor to give me better access to the decoupler pulley. A breaker bar makes simple work to crack the pulley bolt loose.

We got heavy rain Monday afternoon, right at the point I was ready to reinstall the water pump and belt side of things, went out before dark but decided to scratch it and finish up first thing Tuesday. I ended up buying a set of the ratcheting box wrenches - I didn't need them for removal but the 2 bolts on the water pump it made life better!
Filled her up with fresh coolant and fired her up - much quieter and no "dieselly" sound, which I didn't even realize it was there until after this service. The belt was SHOT, and I am guessing the decoupler and idler were worn.

The oil filler gasket got replaced too, the old one snapped in half on removal.

Headliner guy was scheduled for Wednesday and the car wasn't going anywhere so I decided to tackle the SAS cleaning. It's been setting the same ant-skid warning light and message so I figured I would clean it up and re-install before I get into oil and trans oil changes. I either shot myself in the foot or dodged a bullet, I now have a whole host of CCM, CEM, PSM, ICM ECM, CEM codes and got the BRAKE FAILURE/SRS/ABS/AIRBAG no lights, dash and doors intermittent and shifter locked up on a test drive/amazon return. I'll recap here but I think it will be a new thread since it now involves a different set of issues.

 

[gezaphoto]

For the clock spring I have read up on SS and other forums about the cleaning process, tedious attention to detail, but I had the time to do it. The codes in VIDA have been consistent:

BCM-C110787
BCM-U042864
SAS-C009404

Leads me to believe a) it's dirty b) it's shot if cleaning doesn't work.

Same classic symptoms, showed up occasionally and got worse until it comes on immediately on startup and doesn't go away. I had a puncture and tire replaced with a new alignment and it didn't help.

On removal I could see the inside of the steering wheel was dirty, and the SAS had a bunch of hair and grime. I only spend teh back/clock spring portion, I didn't want to get into the from ribbon section as it wasn't coming apart and I didn't have a replacement on hand. This may have caused issues by not cleaning it, but my understanding is it is just the board and metal with the slit that need major attention. Please correct me if I am wrong on this.

Marked every part in OCD fashion, cleaned with rubbing alcohol and canned air, re-installed and got the same codes, plus a couple extras, I decided to research a bit more and realized I needed* to calibrate in VIDA and reset the clock spring manually. *this is where I may have totally screwed myself lol

On install after battery had been disconnected for a couple hours:
BCM-C111768
BCM-U042864
SAS-C009404
BCM-C110668
SAS-C008F44
BCM-C110787
BCM-C110687

After clearing and re-reading:
BCM-U042864
SAS-C010029
SAS-C010129 - Analog sensor out of range - this is what made me think the calibration would work, or the unit was toast.
SAS-C008B64 - Steering angle overflow

I left the car overnight and calibrated with VIDA - the SAS failed and everything else passed. I let the car sit, then battery disconnect, sit for 15+ minutes, airbag out, steering wheel off again and turned the SAS left to the stop, then back, to the right, then left stop and 2.5 or so turns to the 1 o'clock position, yellow in the window, then reinstalled everything and calibrated in VIDA with the same results as the first VIDA calibration. Same behavior - anti-skid pops up with 4.5 degree turn of the wheel left or right (010029/129 codes?) and sets the codes.

Initial state:
BCM-U042864
SAS-C010029
BCM-C110787
SAS-C010129

Under Delivery:
BCM-U042864
SAS-C009E64 - CPU-CPU communication fault
SAS-C010029

I cleared the codes and let the car sit for the headliner guy to do his thing. Fresh headliner in, I have a break in work at 3:30pm and some Amazon returns so I take a test drive over to the UPS store. Everything is smooth, no dash lights, steering is fine, I make a couple 90 degree right and left turns, then I make a right and hit my wiper/spray to clean the windshield. The wipers stop partway across the windshield, I hit it again, they start going random, stop, start, then the dash lights up - Brake failure, SRS, ABS, Airbag, I smell electric burning (maybe? still out gassing headliner glue and the window was down) I pull into the first parking lot and everything is flashing, dying, on off etc.

Long story short I get my GF to bring the VIDA laptop and DICE so I can pull/clear codes. It was a laundry list of codes, ICM, UEM, HCM, SRS, PSM, DIM and so on. I cleared the codes but it was struggling to stay connected, I repeatedly got the "connect a device" error even though DICE was connected, and it was very slow. Most of the DTC's not there is a CAN-bus issue. I disconnected both battery connections and held them together to reset the system, non of the "quick" fixes had much effect.

After clearing the codes that I could I was left with these under initial state:
CCM-E001
ICM-E001
UEM-E001
BCM-C110787
BCM-U042864
PSM-E001

Long story short, I finally limped the car home at 11pm after manually pushing the shift interlock in, starting in neutral and holding in gear. Luckily the headlights and brake lights worked.

Before I post this as a new thread (I believe that's protocol) would this be a SAS triggered issue or a CCM CEM caused by a short (ie headliner guy mangled something)

Now comes some serious troubleshooting, I have been scouring threads and spent time reading in VIDA code by code. I have the Xmodex flowchart but haven't had time to test anything yet today. SAS is being delivered Friday.

 

[ChitownV]

So, your P420/430 codes are gone now? The exhaust is good and not rusted?

The SAS, good to order a new one. I do have a question about the history of your XC90. Is there a chance it could have been a flood car, seeing you have these control module communication issues and faults?

 

[gezaphoto]

So, your P420/430 codes are gone now? The exhaust is good and not rusted?

The SAS, good to order a new one. I do have a question about the history of your XC90. Is there a chance it could have been a flood car, seeing you have these control module communication issues and faults?

Hahaha, only since the battery was disconnected and I only made it a couple miles down the road! I am hoping they are fixed with the extra maintenance done, but not holding my breath.

I haven't seen any flood like damage, it was bought CPO from the Sarasota dealership with a warranty left on it, so unless there was some really shady dealing I doubt it. It's possible there have been spills etc, I have 3 kids and a dog and everyone except me thinks the car is a snack bar lol. I am leaning towards the SAS being a major player since that was the last "repair", aside from the headliner. Haven't had a chance to pull up the removal process in VIDA to see what/if any wiring could have been damaged with the headliner just to rule it out.

My plan is to check the exhaust thoroughly when I'm doing the oil change and trans drain and fill. Also, I have been driving with the splash guard off since the last oil change, it had some stripped and missing bolts (from previous owner/dealer?) and I finally got those delivered but haven't had time to chase the threads and remove the one stripped in place, doubt it would have any effect on the cat codes, but I figured I would add that note.

SAS will be here tomorrow, I just went to unlock the car to do a full battery disconnect/drain any residual charge before hooking up VIDA to see what my current DTC's are before I try to troubleshoot. I unlocked the door with my key, it set off the alarm (Possibly since I left in neutral in case I had to move it) then it unlocked all the other door EXCEPT the front passenger, FOB didn't work this time, although it will randomly work for all. (Worked fine before yesterday's issues). Car fires right up, shift lock goes on, sometimes the dash lights up, other times it stays blank.

Plan of action for today:
disconnect battery and drain charge in system
re-connect and pull codes with VIDA, maybe clear if there are a bunch of minor and re-read.
Read up on the headliner pull to ID any potential short circuits
Start the Xmodex flowchart for the CEM and then DIM
Install SAS when it arrives tomorrow and see if everything I do today is a waste of time 🤣🤣

Am I on the right troubleshooting path here? Different starting point? I'm solid with the mechanics but getting into wiring and diagrams and where to start makes my brain hurt!