C5 Ecu Swap Over Question

[jonnie45]

Hi

 

Apologies if this has already been asked - I did use the search facility but "ECU" is not allowed as it is too short a search term.

 

Does anyone know what will and will not work if I take my ( 2005 1.6Hdi diesel C5 ) ECU out and swap in a used donor ECU of the same model?

 

My ECU has issues ( long on going saga with second hand salesman and his mechanic mate ) progress on this issue is slow and difficult.

 

I wondered what would happen if I sourced a used unit online and swapped over myself?

Would just trying do damage or harm?

 

I gather the immobilser electronics are not part of the ECU but perhaps the two systems "recognise" each other - would the immobiliser refuse to talk to a replacement ECU?

 

The CD player security pamflet says no entry code is required on the actual CD player because the CD player recognises the car so I am guessing that it perhaps recognises the ECU and would reject a clone with a different

electronic ID.

 

Of course I would expect to have to go to someone who can plug into my donor ECU and probably reset some items, perhaps the mileage, elosys readings  would need copying across.

 

Anyone done a swap?

 

Whats involved?

 

Jon.

 

Current ECU details: Runs fine for a while - connection issues suspected within the unit, spurious errors but always only after running for 30 mins or so ( suspect temperature affecting some hairline crack in a circuit board or similar ) it can put the car into safe mode and sometimes the car becomes completely unresponsive ( as if battery had been removed ) - several people who claim to know what they are doing have looked at it without any success. Always interested to hear suggestions but the problem has existed for a year so I am not hopeful that a simple bit of advice will solve the issues on this unit.

 

 

 

[paul.h]

I am not sure about this but I think people who try a used ecu usually get the keys and possibly the bsi so the immobiliser is not a problem. It would need a diagnostic to tell the ecu what equipment your car has and it might include the injectors, esp, cruise control, air con, something on the radio so it is recognised since they are usually coded to the car (or you could also get the used one), other options.

 

You could consider having your ecu checked and fixed if you are convinced this is the problem.

[jonnie45]

Thanks Paul

 

I think maybe you are right I should send the ECU to someone for testing.

 

The second hand car dealer and his mechanic mate with whom I have been wrestling for some time claim to have done this already but it could have been

any old tinkerer so perhaps time to see if someone out there is a little better.

 

Cheers

 

Jon

[Rookie2]

Hi jonnie

 

Just a thought, .

 

The games console "Xbox" suffers from a fault called "The red ring of death" The problem is caused by dry and cracked solder joints on the circuit board. I have. in my time, fixed about half a dozen of these xbox using instructions I found on line.

 

The repair simply involves removing the circuit board from the xbox, getting a powerful hair dryer or heat gun and heating the board uniformly until you see dull looking soldered joints turn bright and silvery. You then leave the board untouched for a few minutes to dry

 

Sounds a bit strange but believe me, it really works and it has the effect of reheating every joint and re-soldering.= it may be worth a try on your ecu but careful not to overheat it, just watch for what appear to be "Dull" joints turning bright and silvery.