Volvo XC90 Faults after Swirl replacement

[Arash79]

Hi Guys,

I recently replaced by swirl flap which involved me removing the intake manifold and injectors.

After carefully replacing everything the car turned on and ran fine, but when i attempted to drive the car I got an ABS Service Required error on the dash and a check engine light came on.

I connected VIDA and I got the following errors.

BCM-0101 Communication between control units Communicational problems with ECM
ECM-23D0 Injector cyl 4 - Signal missing
TCM-0A31 Control module communication Signal missing from Engine Control Module (ECM)

The car now runs a bit rough and will not drive properly.

I think there may be an issue with the connector on cyl 4 so I'll check that tomorrow but I have no idea what the other faults are.

Any help will be greatly appreciated.

I forgot to mention that I also removed the throttle body to clean it and I also clean inside the EGR with a rag, but didn't spray anything inside it.

Cheers

[SwissXC90]

Both the BCM and the TCM talk to the ECM on the same high speed CAN bus

Help us to help you by stating what year your XC90 is

For the rest of my message, I'm assuming the same year as mine, a MY2009.

The BCM connects via high speed CAN (HS-CAN) bus to the CEM
The ECM and TCM also connect on the same HS-CAN to the CEM
On some engine types, an additional connector may be present in the engine loom.

You should measure continuity from HS-CAM H side between all three modules: CEM, BCM and ECM
Likewise on HS-CAN L side.

Check the signal using a scope.

If you have any connection problems, check the connector on the CEM for corrosion
Repair any corrosion found. New pins may be required!
If the CEM is badly corroded, then a replacement CEM may be required! As the CEM is the central brain of the car, only a new CEM from Volvo can be fitted. 2nd hand CEMs won't work.

[Arash79]

Thanks for your response....yes my car is a 2008 Volvo xc90 d5

[Arash79]

Also the car has been sitting there for about a week with the battery connected then when the car finally started the battery was nearly drained....could low voltage on the battery be giving me these issues as the car didn't have any problems before

[SwissXC90]

Originally Posted by Arash79

Also the car has been sitting there for about a week with the battery connected then when the car finally started the battery was nearly drained....could low voltage on the battery be giving me these issues as the car didn't have any problems before

Yes, low battery voltage can cause many erroneous faults exactly like the ones you described.

Charge the battery up overnight
Clear all fault codes
Check to see if any return
If none return, take the car for a test drive and check codes after a completed test drive

You may be lucky and find you only had a low battery voltage issue

[Arash79]

I sorted the issue...it was a loose connection on the throttle body cable. I reconnected the connector and the can bus error went away.

I also fixed the injector loose connection issue by folding aluminium foil and placing it inside each of the contacts. So for so good.

Thanks for your help guys.