HDI won't start

hi there
Got a C3 1.4 HDI.. just redid the turbo, blocked of the EGR and sorted all the oil leaks...

Problem:
everything works in the car but it wont start. it turns over but wont start.
it is making a buzzing noise in the fuse box in the engine compartment.
i had a diagnosis pc on it before and now when i plug it in it wont even read or pick it up. IOW
i cant read any codes or find the problem

is the ECU dead or what??
is there a way to test the ecu at all??

i suspect the service dealer might have shorted the ecu on the positive terminal...

do i need to replace the ecu and what all does this encompass???

thx in advance

Welcome to the forum c3stevie,

is there a way to test the ecu at all??

Try BBA Reman (via their ebay store) who can test and repair these sorts of things.

do i need to replace the ecu and what all does this encompass???

If you want to change the ECU, you need a matching BSI and the transponder key for that BSI. They come as a kit, you can find the right one HERE - on ebay. The BSI and ECU just unplug, if you get a BSI and ECU from a very similar car, with all the same specifications and optional extras you won't need to program anything other than the radio.

the buzzing might be coming from a relay. try finding which relay is buzzing and that might give you a better idea of where the issue is coming from

thanx for the help so far... i have found a person that will test and if need be repair the ECU... i hope that works as a new ECU + programming will cost me 1200 bucks and thats in Ponds... i can get second hand but the price is still very steep...

btw can somebody familiarize me with the components... left of the battery is the ECU.. to the right of the battery is a fuse box behind the battery is another ECU type box below the cubby hole is another fuse box of sort now i hear under the dash is another box

so which ones will have to be replaced if i dont come right with the repairs??
i hear some ppl talking of changing the instrument panel as well, why??

then one more question:
my ECU is Bosch right
the fuse box thingy to the right of the battery is Siemens and the one below the cubby hole is Siemens as well.. i spoke to a guy today telling me everything must all be or Siemens or Bosch but not a mixture.. he say Bosch runs on 12v and Siemens on 6V... is this true?? cant really be cause my car ran perfectly well with the mixed items...

btw can somebody familiarize me with the components...

left of the battery is the ECU..

Engine ECU, controls the injectors mostly.

to the right of the battery is a fuse box

The engine bay fuse box is also called the BSM. It contains fuses and relays and some Maxi Fuses hidden from view

behind the battery is another ECU type box

Power Steering ECU, controls the power steering motor.

below the cubby hole is another fuse box sort of

Supplemental fuse box

now i hear under the dash is another box

The interior fuse box or BSI. Contains fuses, relays and a computer. Does the security and most of the computer interface and control.

so which ones will have to be replaced if i dont come right with the repairs??

Engine ECU, BSI and the key fob.

Engine ECU is coded to the BSI, they must be changed as a pair if they are not new. The transponder key is linked to the BSI and needs to be included in the kit otherwise the car won't start.

i hear some ppl talking of changing the instrument panel as well, why??

Some cars the mileage is stored in the dashboard display (instrument panel), but yours is in the BSI (2006 C3) so you don't need to change it.

my ECU is Bosch right
the fuse box thingy to the right of the battery is Siemens and the one below the cubby hole is Siemens as well..

You will find a mix of manufacturers for different kit on the C3, its not a problem. If you buy a kit of parts then get an exact match on the fuel type, model an year. Then you will have all the right parts.

i spoke to a guy today telling me everything must all be or Siemens or Bosch but not a mixture.. he say Bosch runs on 12v and Siemens on 6V... is this true??

No

Thx GURU... you have been a great lot of help... i eventually found somebody that can repair my ECU.... I HOPE!!!! He says its common for ppl to short the ECU on the pos of the battery as the wires are just long enough to reach there... i do recommend what i will be doing and thats to stip some duct tape on those 2 square headed bolts that attach the ECU to that plastic frame... i will let you know what the outcome is...