C4 1.6 VTR petrol not starting

[mistuart]

Just bought an 05 plate C4 coupe 1.6 petrol.
The guy I bought it from sold it because it wouldn't start.
I bought it as a project to see if I can get it going again.
Hope someone might be able to help me.
The starter turns for less than a second then stops as if the starter was faulty.
I have cleaned the body earths, replaced the battery and starter motor.
Previous owner said he had tried a new fuse box.
I have noticed if I disconnect the crank sensor it will turn over for 3-4 seconds then cut out.
If I connect the red starter solenoid wire to 12v it will turn for as long as I connect it to 12v.
Thanks in advance for any advice.

[Stickyfinger]

1st stop...a Lexia to find out just what is happening.
http://www.frenchcarforum.co.uk/forum/v ... 19&t=29178" onclick="window.open(this.href);return false;

You really struggle to work on a PSA car without one or access to one.

[mistuart]

Put car on Lexia and got the following related codes
P0615 Starter motor control relay open circuit
P1694 Controlled engine stop/start DAMP short circuit to earth.
Anyone know where the starter control relay is?

[wheeler]

Anyone know where the starter control relay is?

It's an integral part of the under bonnet fusebox.
Can you read live data of the engine RPM ?

[mistuart]

I doubt it does one turn before stopping so not going to be able to read the rpm.
I substituted the crank sensor with a known good one but still the same.
Thinking maybe immobiliser/BSI problem.

[wheeler]

The immobilizer on this car doesn't inhibit the starter motor at all, if the key it not recognised the starter will turn until you let the key go, it would also display on the central dash display something along the lines of immobilizer faulty/key not recognised.
This is a very strange fault, not one I've ever heard of on a C4. Have you checked every fuse on the car and also confirmed all the fuses are in the right places (remember someone has been messing with this before you)

[RichardW]

If you switch the ingition on and then energise the starter manually, is it possible to start the engine?

I'm not 100% sure, but the presence of a starter relay in the underbonnet fuse box suggests to me that starter operation is a network controlled function. Something is causing the relay to drop out - no idea what though! Is the main power supply to the under bonnet fuxe box in sound condition - it's possible that operating the starter causes a volt drop in the system that de-energises the fuse box wnough to drop the relay out. No idea either why disconnecting the crank sensor should make it turn over for longer. You'd really need a wiring diagram to pursue I think...

[mistuart]

Engine will turn over normally if I run a separate wire with 12v to the starter solenoid but still doesn't fire.

[citronut]

ignition switch??????

[citronut]

is this car an Auto

as on a goooogly search this came up

http://www.datsc.com/tabid/122/OBD-Erro ... fault.aspx" onclick="window.open(this.href);return false;

[mistuart]

It's a manual

[mistuart]

Took car to Citroen dealer they have diagnosed engine ecu £1000!
Have bought a matching second hand bsi, engine ecu and key off ebay.
I plan to fit them then tape the new key in the reader under the dash so I can use my existing ignition key.
Does anyone know if I need the key reader off the donor car?
Will the stereo beep at me as well?
Thanks in advance.

[wheeler]

The key reader is not a coded part so you wont need one off the other car.
Yes your radio will beep as the VIN in the BSI & radio set wont match, easily sorted though.
Also make sure if possible that you make a note of the VIN of the donor car and the transponder security code if you can in case you need to recode keys in the future.

[mistuart]

Car is all running now it was the engine ecu.
Found a company called Cartech Electronics, if you send your faulty ecu to them they transfer any programming or coding off yours so it's a plug and play play.
Sent it off Friday morning and got the replacement on Tuesday morning.
Only cost £250 so saved a fortune.
Hope this might help someone else.