Thought I would start a new thread but first a little background.
I purchased this car with a slipped timing chain, spun a cam bearing (don't know what you call it anymore with no bearings?) so I replaced the head.
Got it all back together and the car ran fine but the supercharger was making a noise so I replaced the coupler.
Got it all back together started it and all kinds of codes came up, engine misfires, trans code etc. Wouldn't idle, ran rough.
I checked all the connections but after all the work I have done I was fed up so sent it off to a local mechanic hoping he could hook it up, find the problem and remove the codes.
He looked into it, erased the codes most went away but the one that keeps coming back is
P1643 CAN TCM TOKEN message missing
He has decided the ECM needs to be replaced and I don't think he wants to look any further. He says he has checked all the connections, etc and found nothing but I think he is tired of it too so I plan to take it back this week and start over on it.
There are various things I feel it must be since it ran fine for the first few minutes after I got it all back together.
The mechanic did check the cam timing, it is fine, flats line up he says but I think I will double check this first anyway.
There are many electrical connections I need to check, vacuum leaks etc, it feels like a big vacuum leak to me but as I said I got busy with other things and got tired of messing with it, thinking it would be easy for a mechanic to find I sent it to him.
One more thing, the gas is at least 2 years old in the tank, I have had it nearly 2 years and I think it sat in other shops at least 6 months to a year before I got it, I would guess old gas could cause similar problems but the mechanic seems to discount this, I think he is tired of looking.
My main question is
If the ECM is bad, or needs to be flashed what would the symptoms be?
Would it cause the behavior I am describing?
I have found rebuilt ECM's, from what I have heard it would still have to go to a dealer to be programmed for my car, is this correct too?
My gut says it is something simple and not the ECM, just looking for suggestions
Thanks in advance
Rusty

 

Is it a BRAND NEW battery? If not, change it.

 

You mention changing heads . . . did you use the replacement one with the correct Cam Position Sensor? Connected?

Past that, obviously an electrical problem. After disconnecting a battery cable remove and reinstall the ECM and PCM to clean the connections. Also might want to remove and reinstall the various nearby relays . . . couldn't hurt. The P1643 doesn't give you much beyond throwing parts at the car.

The ECM's have a history of capacitor failure requiring a rebuild, and while the car might start and run with a replacement, a dealer re-flash might not be a bad investment.

 

dsnyder586 - Battery is new but it has been sitting awhile, thought about checking that.

test point - Cam Position Sensor, did not swap that from old head to new one, I don't think? Will check on that too.
So back to the question, if the ECM needs to be reflashed, or is bad, would it run this poorly?
When/if I install a new ECM you are saying it will it run without a reflash or reprogram just not well?
Good points so far, any more?
What about the gas, injectors? Although I guess it would not have run well for the first few minutes if the gas was bad, answered my own question!

 

I just sent my ECU to ASI in Tennessee. They will test it for $55, and if it requires a rebuild they apply the test cost to the repair. Mine needed a repair and now it works fine, no reflash required. Insurance and shipping add significantly to the cost, but I don't think you want to send it without insurance.

 

RJ237, thanks, great to know!
I will check a few things first then send it in, fortunately it is really easy to get to on these cars either good engineering or they knew something!

 

Can a proper jag-type OBD tool see each of PCM & TCM properly? And the ICM (dash)? If not, may be a wiring problem.

 

I must say, it would be quite a coincidence if your ECM broke at exactly the same time as you worked on the engine. My money is on a connection or Battery.

 

+1 on connection. Using a meter to track the green and the yellow CANbus wires is not too difficult.

 

I agree, I think it is most likely something simple since it ran so well for the first 5 minutes after the head replacement. CEL was on but it ran fine so it might have just needed a reset initially.
Will check the obvious then send in the ECM
Thanks
Rusty

 

Just heard from ECI in Tennessee, they couldn't find anything wrong with the ECM. Will get it back next week, bring the car back home from the mechanic and start tracing wires, my time is a lot cheaper than his!
Will have questions then I am sure!
Rusty

 

Jaguar SDD with the appropriate OBD cable can read everything and just as easily "if you don't know what your doing," destroy everything !!

 

You misunderstood. I know it is able to do that. What I meant was: if someone connects it to the problem car what does it see regarding those modules? BTW, that's the only way my final sentence makes any sense.

 

Apologies if i misunderstood your thread...to try and better answer your question i looked at some of my old training manuals i was given, here is a screen shot of all the modules and their responses when SDD interrogates them.
Green is good, a RED X or ? is either module not fitted or that module has an issue. TS
SDD Module status.docx

 

You might not have the correct information on what P1643 is. This code indicates an ECM/TCM communications failure. Take a look at the wiring to the TCM and be sure its correct. The code also indicates a possible TCM failure. You might be looking at the wrong module.

 

Thanks for the replies, finally back in town after two weeks on the road for work. ECM is waiting for install.
I have thought all along it is most likely a wiring problem since I had the engine out there is a pretty good chance I missed something during the install. My thought of taking it to the mechanic was that with his computer and his lift he could track it down and get to it much easier than I could but beginning to wonder!
Hope to get some time to play with it this weekend.
Rusty

 

How did you resolve the issue ?

 

Sidct, turns out it was the ECM, the place that tested it said even though it tested good it could still cause problems, turns out they were right.
Found a good used ECM with matching numbers, plugged it in and everything was back to normal, runs great, finally!
About the ECM, after installing the new (used) unit I pulled the old one apart and turns out there was a bit of corrosion inside, looks like it didn't seal correctly on one of the corners, just a freak thing I guess assuming that was the problem.
Rusty

 

What car details? Engine? Year?