[dello2002]

Hi all,

I have a 2003 diesel.

I bought the car with a knacked engine so couldnt start it before hand. I have now dropped a new engine and cranks over but will not fire up.

Plugged diagnostics in and it can only find the immobilzer..... No communication with any other modules e.g engine ECU, ABS, airbag etc.......

3 faults on the immobilzer regarding communication with the engine ECU.

Done the usual fuse and relay checks.... all good..

Anyone else had this issue or can point me in a direction to start checking.

Any help would be really appreciated as it is being used for a charity event and really need it running!

Thanks

 

[aquanaut20]

Did you miss a ground connection when you swapped engines.. Confirm ALL your power and grounds...

 

[dello2002]

Hi
aquanaut20

I have checked grounds. There are 3 on the back of the engine. 1 thick one and 2 small ones. All postives are connected.

Thanks

 

[aquanaut20]

Now confirm you have powers and grounds at the ECM...

 

[dello2002]

I did check for power at the ECU and it did show live and ground and when i plugged in the middle ECU connector the tank fuel pump primed so im guessing the ECU does have power and to a curtain extent. just really strange why my Autel diagnostic can only see the immob module......... im guessing even if the ECU was fried i should still be able to read other modules like on other cars. I am a mechanic but this is frying my brain!

 

[aquanaut20]

Communication issues are most times associated with lack of correct power and grounds, followed by Comm circuit issues..

The ECU may have up to 3 different feeds for power and grounds..

Do you have any 5vdc refence voltage at any sensors ?

 

[aquanaut20]

Do you have access to a scope ??

 

[dello2002]

No i havnt dived in that deep yet. I will double check all my grounds just incase i have missed something.