Hello friends! I have a 407 coupe 2.7 hdi from 2007. For almost a year I have been struggling to start it and I can't. The car stopped while driving on the highway. I have no communication with the Ecu, it doesn't crank.
I measured the Can network at the obd plug and as a result I have: can H 0v and go to ground and can L is almost identical 0.1v and a resistance of approximately 98ohm. I changed the entire starting kit (ECU, BSI, Key contact, including bsm).
Please help me with a BSI electrical diagram and an explanation if possible, what does the Can H network go to ground? Thank you in advance!!!
2.7 hdi can H 0v and grounding to earth
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mickthemaverick
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Re: 2.7 hdi can H 0v and grounding to earth
In order to access the diagram system I have I need to know the RPO number of your car as shown in the red box below? 
I used to be indecisive, now I'm not so sure!
I used to ride on two wheels, but now I need all four!
I used to ride on two wheels, but now I need all four!
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Sed13
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Re: 2.7 hdi can H 0v and grounding to earth
Is it good?
Last edited by myglaren on 21 Oct 2025, 15:23, edited 1 time in total.
Reason: Images rectified
Reason: Images rectified
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mickthemaverick
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Re: 2.7 hdi can H 0v and grounding to earth
These are the diagrams I could find:
I hope that helps you out
I hope that helps you out
I used to be indecisive, now I'm not so sure!
I used to ride on two wheels, but now I need all four!
I used to ride on two wheels, but now I need all four!
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Sed13
- Posts: 4
- Joined: 21 Oct 2025, 02:24
Re: 2.7 hdi can H 0v and grounding to earth
Thank you very much! I'll try this tonight, see what I can solve. I'll be back tomorrow with the result!
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wheeler
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Re: 2.7 hdi can H 0v and grounding to earth
I'd start by disconnecting all ECU's from the CAN & see if the short goes away.
If you disconnect the ECU does the resistance change?
If you disconnect the ECU does the resistance change?
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Sed13
- Posts: 4
- Joined: 21 Oct 2025, 02:24
Re: 2.7 hdi can H 0v and grounding to earth
Hello guys! I disconnected for testing ECU, Esp/abs, PSF1, suspension computer, gearbox computer without any result for that Can H that goes to ground. But if I disconnect from BSI plug 40v NR, Can H no longer goes to ground. Can a complete BSI diagram or only on plug 40v NR? I did all the measurements in diagram 407 starting all the wires are good. I have the following errors:
Last edited by myglaren on 23 Oct 2025, 20:37, edited 1 time in total.
Reason: Images corrected.
Reason: Images corrected.
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wheeler
- Posts: 7893
- Joined: 21 Sep 2002, 19:07
- x 1044
Re: 2.7 hdi can H 0v and grounding to earth
With only the ABS unit disconnected can you resistance check across pins 1 & 13 then 2 & 14.
Both should be 120 ohms
Also check each of these wires for shorts to ground or each other again with ABS unit disconnected.
Both should be 120 ohms
Also check each of these wires for shorts to ground or each other again with ABS unit disconnected.