XC90 2.5T 2004 No spark cylinder 1

[RickHaleParker]

Er... CEM-B sounds like Chinese to me... yet I guess it's a generation that has some PIN protection in case you want to program it from the ODB2 plug. Am I correct? I have a Chinese DiCE unit.

CEM-Brick the brick shaped CEMs used in 1999 - 2004 P2s. Best name I could come up with for that generation of CEMs. The CEM is protected against change by a six byte PIN number. It is the one CEM that we never been able to crack over the CAN bus.

Did you check the wiring to coil #1 for shorts ? A short could take out an I/O port.

[Dragoz001]

Thanks for the explanation.
Yes I checked the wire for short circuit.

[Dragoz001]

Hi,
I finally can post some update on that problem!
I ordered a used ECM fom eBay. The donor car was exactly the same as mine, released a few months later.
I managed to find someone to clone my ECM into the one I bought. It took 2 weeks to send it and get it back...
The engine started with the new ECM but it was stuttering, black smoke and when I pushed the throttle it almost stalled.
I checked the cylinder #1 spark plug and could see that I now have sparks! So the original problem is fixed at least!

Important to mention here that I had E85 in the tank. The car got reprogrammed for E85 by the previous owner.
He gave me a small device that I can plug into the OBD2 socket and I have a menu to get back to the original setting or program the MF setting (Multi-fuel for E85).
So I decided to redo the MF programming. I could do it successfully even though the small device was set to work only with one ECM (serial number check or something like that).
I also did a reset procedure that I read somewhere (unplug the battery for 1 hours with + and - connected).
After that the problem seems fixed! The engine seems to run well (I ran it only a few minutes because it was late).
Today I will plug the VIDA to erase the DTC and see if some codes come again after a try on the road.

So it seems that the "cloning" does not copy all data from the 1st ECM to the second. At least it's my interpretation...

[Dragoz001]

For those interested I have some news about my problem.
The ECM works well actually.
I have found a second problem on the car!
There was a vacuum leak at the intake manifold gasket on cylinder 1 !

[Dragoz001]

Last update in case it may help someone in the future.
The car now works perfectly!
Smooth idle, good power and MPG increased drastically (from 18 l/100km to about 13).
Basically I had 2 problems:
- 1 recent was that the ECM failed (output for cyl #1) and had to be replaced
- the 2nd was older (I saw several invoices of the former owner mentioning rough idle, lack of power, etc.) and was a vacuum leak at the intake manifold gasket next to cylinder #1. The leftmost screw of the manifold is a bit hard to reach and was not tighten enough. Probably the cause...
Thanks again to RickHaleParker who took time to help me.