Baffled by ABZ

[ainarssems]

Having snags getting into ECU at moment, dialouge box on VAGCOM says 'too many communication errors to continue'

Well that might be your proble, possibly there are too many errors in communication between ECU and immo as well.

Bad connection or excessive EMI noise.

PS
When you remove memory chip it is good idea to solder socket in it's place an plug new chip in the socket so that it is easily removable in future and to use rewritable chip instead of write-once.

[SimonT25]

hi all

Just had the ECU checked which has had the IMMO removed and it is free running without any faults. Now i just dont get that

So if not immobiliser then what?

Ross Tech said that the comms error is more than likely to be because it can only see one module therefore there is no load on it so just goes a little bonkers.

Any thoughts?

Tested VAGCOM on a driving polo and all is well with it.

Next is to completely replace the loom with another one!

Unless someone has a new idea?

Thanks to all watching and thinking about it

[PsYcHe]

How did they test the ECU? On another ABZ engine or just with probes?

[SimonT25]

ECU tested with probes using an oscilloscope and a power supply.

I can find out exactly if you think it will help!

regards

[SimonT25]

It has just occurred to me that i havent connected the alternator as yet as i was eliminating things that may be pulling 12volts down.

Is it essential that the Motronic must see 14v on start?

Also as it has an independent fuel supply it is not controlled by the Audi loom fuel relay there is no power to the pin on the ECU!

Again must the Motronic see 12 volts from the fuel relay to maintain engine running?

I will go and amened these things to see if this will make a difference. I would of course appreciate it if anybody on the forum does know this to be fact incase I rectify these conditions and it makes no difference.

Regards and thanks in advance

Hanging in there by the thickness of my fingernails!

[ainarssems]

Alternator is not required, not sure about fuel pump.

Edit: At least alternator does not need to be running, maybe it needs to be connected. I have been running muine without belt but alternator was still connected.

I think it does not need alternator or power from fuel pump relay but it's worth giving a shot just to rule out.

[cerips]

Have a look at self study guide 161, it covers the Audi V8 and the motronic M5.4 ecu.

[SimonT25]

Thank you V much for all the posts. All the help etc

Where can I find the self study guide? I'll try to simply google it for any info.

[ainarssems]

http://www.volkspage.net/technik/ssp/ssp/SSP_161.PDF

[SimonT25]

Thank you for the link as I looked last night and could not find anything on google.

Is there an English version? Would save a lot of copy and pasting relevant bits into google translate!

Regards.