Replacing the ECU,BSI and Transponder with key set

Hallo.
I have a 2004 Citroen C3 1.4 Hdi ( I think it is an 8valve ). The car doesn't want to start and all the mechanics/auto electricians came to the conclusion that the ECU is the culprit. Current fault code was P0203 and I think there was also a code in the beginning P1197/P1179 (can't remember). It all comes down to the car cranking but no diesel goes to the injectors and therefor no starting. I remember all the fault codes pointed to fuel related problems.

I want to replace the ECU,BSI and Transponder with keys altogether. My current ECU is a Siemens SID 804 5WS40110C-T
The question is : Can I replace my siemens sid 804 with siemens sid 806 ECU, BSI and transponder ?
This is the only 2nd hand part set I can find at the moment in South Africa.

Thank you,
Edzard.

Hi Edzard, welcome to the C3 forum,

edzard wrote:Current fault code was P0203

Injector Circuit Malfunction - Cylinder 3 for P0203. Suspect injector, you can swap injectors 3 and 4 over and see if you get the same or different (P0204) code - this can prove if its a faulty injector or not.

again, P0203 Intermittent fault,Cylinder3 Injector circuit Injection time correction outside limits.
Looks like a faulty injector.....
https://citroenc3owners.com/diesel-citro ... -t385.html


Test wiring from the injector plug to the corresponding pins on the ECU with a multimeter.

edzard wrote:I think there was also a code in the beginning P1197/P1179 (can't remember).

Permanent fault, Injector(s) control: Fault code: P1197
https://citroenc3owners.com/diesel-citro ... -t488.html

edzard wrote:I want to replace the ECU,BSI and Transponder with keys altogether. My current ECU is a Siemens SID 804 5WS40110C-T
The question is : Can I replace my siemens sid 804 with siemens sid 806 ECU, BSI and transponder ?
This is the only 2nd hand part set I can find at the moment in South Africa.

I don't know if you can swap 804 for 806, it is possible to have the ECU tested and repaired by companies like BBA Reman.

I would test to ensure its not a injector or injector loom fault before changing the ECU (see above). If the ECU is blown due to a faulty injector or loom, you will damage the new ECU if the original fault is not cleared first

( I think it is an 8valve )

8v is SID and 16v is Delphi - its an 8v.

You mileage is 110000, which could easily be a bad injector and I would thoroughly prove or disprove them before getting stuck into the ECU

Thank you for the reply Arfur Dent.
I will first check the loom and injectors then !

https://citroenc3owners.com/diesel-citro ... -t901.html

Injector leak off testing

Hi Arfur Dent.
The stupid car is still not starting and I got a 2nd hand ECU,BSI,Fuse box and 2 keys from England.It came of a running car that they were breaking up for spares. I plugged it all in and swapped the key blades with the old keys.
The car locks and unlocks with the remote.
Trying to start it and still the engine just cranks but with no positive outcome.
Trying some quickstart/brake cleaner proved that the engine wants to run but as soon as you stop spraying it dies. The good thing is that it got rid of that annoying Eco-Mode flashing in the display.

I took the car to the Citroen dealer a week ago but they can't get communication to the ECU. They apparently need the VIN number of the car the ECU originally came out of. Is this true !? What if they can not find this VIN number ?

edzard wrote:I plugged it all in and swapped the key blades with the old keys.
The car locks and unlocks with the remote.
Trying to start it and still the engine just cranks but with no positive outcome.

Did you swap the immobiliser chips over? So you have your immo chip in the blade that's cut for your car?



https://citroenc3owners.com/citroen-c3-t ... -t449.html

edzard wrote:I took the car to the Citroen dealer a week ago but they can't get communication to the ECU.

Check for blown fuses there may not be power getting to the ECU/BSI. Check for power to the ECU and BSI.

edzard wrote:hey apparently need the VIN number of the car the ECU originally came out of. Is this true !? What if they can not find this VIN number ?

Lexia tool/diagbox is asking for the VIN because the software can't read the ECU. Fix the communication problem and you won't need to enter the VIN.

You could enter any VIN that is of a similar year and engine, its just so the dealer tool knows how to communicate. BUT this is more of an indication of ECU/BSI power/communication problem and I think even if you did enter the correct VIN, it still won't communicate as the missing VIN is not the fault, just a symptom.


Getting your own lexia clone tool would be much cheaper in the long run than lots of trips to the dealer.
https://citroenc3owners.com/citroen-c3-t ... -t655.html

What is needed here is a good vehicle electrician.
As the ECU and all the other components have been swapped and the original fault remains, someone needs to find out
just what is going on.
Things are just to complicated to try and guess and diagnose by substitution, not to say expensive if you blow something else up
due to pre-existing fault.
Someone with Lexia might be able to look at it and find the fault, my own car would not communicate via the OBD port simply
because that part of the ECU was not being supplied power from a faulty engine fuse box.

It's very complicated and involves communication between several electronic control boxes, ECU, BSI and Comms 2000 Unit.

jbz2079 wrote: ↑Wed Jul 18, 2018 12:36 pm Things are just to complicated to try and guess and diagnose by substitution, not to say expensive if you blow something else up
due to pre-existing fault.

Oh yes

jbz2079 wrote: ↑Wed Jul 18, 2018 12:36 pm my own car would not communicate via the OBD port simply
because that part of the ECU was not being supplied power from a faulty engine fuse box.

Simple to fix when you know what the problem is but takes a fair bit of working out to get there