Power loss when warm

[mike19691969]

Hi All,

Have read many many threads but just hoping someone may narrow my search. History is unknown for the car.

2006 XC90 auto drives normally for about 5 miles, i.e.warmed up, then loses power and will accelerate only very slowly.
In auto it will not lift above 4th but revs out to 4k+, in manual I can go up the gears but no difference to acceleration. Any and all gear changes are smooth with no abnormal sounds or judders.

Hving checked the DTC's with Vida I can see the CEM-1F00 ECM, Software faulty signal, but is this my problem or do I have an ECU with some sort of tune? below photos of Vida DTC's, if they don't work can someone point me in the right direction to upload photos.

IfI let the car cool and start again then all works normal for about 5 miles.

I am not very experienced with VIDA so any advice in interpreting the result will be appreciated.

Just from reading other threads am I dealing with any of the below scenarios?

I cannot hear any significant whistling but could I have a Turbo / intercooler / pipework issue?

Or could it be related to vacuum?

I will be grateful for ANY help or guidance as I am at a loss where to start looking. I may have neglected to mention some vital bit of info so please shout if I have.

Thanks Michael

[SwissXC90]

Print current faults to pdf
Charge the battery
Go for a drive
Read again

[mike19691969]

Thanks
will charge overnight and get a drive in the morning.

Will post results

[SwissXC90]

And clear faults before the drive

[mike19691969]

Have found that the Mass Air Sensor is non Volvo, well not unless they have started fitting them with cable ties. will post a pic later

I have ordered a Bosch one and will update when fitted and test run.

[Tannaton]

Originally Posted by mike19691969

Have found that the Mass Air Sensor is non Volvo, well not unless they have started fitting them with cable ties. will post a pic later

I have ordered a Bosch one and will update when fitted and test run.

Ah... there might lie the start of your problems - Bodgit and Scarper Motors...

Probably worth checking over the full fuel and air system for the correct parts and method of assembly.

A split air charge hose can cause symptoms similar to that in some circumstances, do you get any black smoke from the exhaust?

[reggit]

Take the fuel cap off, or significantly slacken it and see if that makes a difference.
Very long shot that the tank is vacuuming and starving the engine of fuel - don’t even know if that’s a thing on modern cars.
Vida wouldn’t read fuel pressure faults on my v70 once the ignition was cycled.

Are you getting any warnings on the dash when the car loses power?

[Asiiamo]

Evening,
We have had a very similar issue and we found that the 'Engine Management Relay (MA3) was over heating and the car would basically stop running. Changed it last week and for the moment has been fine. Yesterday drove over 300 miles.

Regards

[mike19691969]

Thanks for all the input.

I believe that I have the problem solved.

After changing the non genuine MAF held in place by cable ties (see photo) there was no change. Mechanic friend suggested EGR stuck open but when I checked the pipe work it wasn't clean but I have seen much much worse on photos here.

I was checking fuel lines etc when I spotted something not connected and it turns out it was the swirl flap rod. Now this was not simply popped off the ball, but the arm that the ball is attached to was off the actuator. Put it back on, cleared codes and test drove a completely different motor with no related fault codes stored.

Now I just need to sort the parking sensor fault and the SAS.

Thanks again for the help I would never have solved this without this forum.

[XJSDriver]

Thanks for sharing - very useful, especially to note that the fault codes thrown up were not very helpful assuming the MAF was the culprit - perhaps using vida to check various sensors may have helped pinpoint the culprit?

As a winter project I am going to look at downloading typical values for various sensors on the car when driving so I can then monitor them and see what changes over time with the hope I can spot a sensor on the way out before problems such as yours appear or if I do get a problem I can compare with a good set of values to see what is different.