Peugeot 207 1.4 VTi no cranl/no comm to ECU

[Farseer]

Hello everyone!

Pleasure to be here.

I'm having this enormous problem with a 207 I bought recently. It's a 1.4 VTi, EP3 (says in the VIN).

What I do know is that some time ago last year, the ECU was swapped (no idea why) but the car ran fine for another good year after this procedure.

It started to randomly stall, up until it just refused to crank. I would turn the ignition, hear a click in the BSI, and that's all. No crank.

Scanning the car, I noticed that there was no comm to the ECU. All the other modules were flagging DTCS for a no comm to the ECU. The BSI had a 0538 "no starter circuit detected" something like this.

Now, I have these two diagrams available from Autodata (AD) and HaynesPro (HPRO) Now, they aren't the most accurate, as I've noticed some discrepancies.

SO FAR:

Result! No power going to C1 and C2 as well as C6 and C30 at the ECU. But here's the problem, if the diagram is correct, then fuses F10 and F5 should supply this, but they don't! Nothing is coming out from the BSM. Only F1 is doing it's job, that is, the ECU provides the ground needed for the relay.

But... that's the issue. The BSM is not controlling the relay that sends power to F10 and F5. I suspected a broken BSM, but obiously changing it for a known good did nothing.

Does anybody know what exactly the BSM requires to control that internal relay? I've found something interesting. A20/C10 and A8/C11 seem to be some sort of comm lines in between the ECU and BSM (seen on the HaynesPro diagram as well). I've noticed that when the car works sometimes (it will sometimes randomly fire up for a moment), then one wire has a 12v the other is a ground. If I ground this wire, I can hear relays clicking in the BSM. Does anybody know what these two wires are?

I have so far scoped the VAN network going to the BSI, it looks fine, no abnormalities. The car does the "key test" that is it beeps with door open. I thought about the fault I was getting, but that circuit up to the BSM is fine. i.e. when I turn the ignition on I'm getting 12v at the BSM. The starter circuit (#100) from connector E2 at the BSM doesn;t send out a signal to the starter, although when I apply power there the starter turns.

My question is, what exactly in these cars send sout a signal that wakes up the BSM and "tells" it to start switching it's relays inside to provide power to the ECU?

CAN lines from the ECU to the ABS and onwards look fine. I mean, not the prettiest data packets, but still.

Thank you all for your help. Maybe somebody could post a OE wiring diagram? Would very much appreciate it!

[mickthemaverick]

What year is the car?

[Farseer]

Hi, it's from 2009.

Here's the VIN if that might help:

VF3**************[VIN obfuscated, can be read by forum staff]

[mickthemaverick]

Unfortunately we currently don't have access to the Stellantis database to look up your car from the VIN. There are a considerable number of different diagrams so in order to get the correct one for your car I need to know the RPO which is on the tyre pressure sticker (5 digit number around the 11890 range) on the door pillar and the choices from each of the following options:

Which body?

Which engine?

Which gearbox?

Which option?

This is an example from me guessing the answers to all those questions so it shows you what you will get when the right info is used.

207 starting.pdf

Example Starting circuit

(548.28 KiB) Downloaded 81 times

You will find the guide to these diagrams very useful which can be found at viewtopic.php?p=782862#p782862

[Farseer]

Thank you so much for your interest, Mick, I'll try to fill out what I can.

Number from the sticker is 10302

5 door saloon
I think it's an EP3, from the VIN number.
Regular 5 speed manual gearbox
I think it actually has the electronic stability program.

Would you have anything with the ECU?

I really think my problem lies in the two comm wires at the A10/11 connector at the ECU.

Thanks! The diagram you sent came in handy. I re checked all the starting components, fan confirm everything that needs to be there, is there.

[mickthemaverick]

This is the only diagram I can find from your info with the ECU on it. I hope it helps!

207 ECU.pdf

Copied from the Servicebox backup

(867.54 KiB) Downloaded 67 times

[Farseer]

Wow, this is what I've been looking for. Unfortunately, if I zoom in the picture blurs. Do you have a higher resolution picture?

[mickthemaverick]

No afraid not. However while it blurs on my phone it is clear on the laptop. Have you tried that?

[Farseer]

I have, unfortunately it is still blurred. May I ask if you could upload it again? Or perhaps if I could trouble you for a zoomed in part of the top left corner with the BSM and it's connections to the ECU and BSI?

[mickthemaverick]

This is the best I can offer so far, click on it to enlarge, I will have another go on the original site and see if I can improve it.

Modified from diagram above

[mickthemaverick]

OK by screenshotting from my big screen I have the diagram left side in 6 parts. hope that helps!!

[Farseer]

Thank you very much for the diagrams. The Haynes and Autodata were incorrect with some of the main power layouts.

I don't seem to have a 8 way black connector on my BSM unfortunately

But I know where the issue lies, although it still bogs me. The BSM is not grounding the R2 relay coil.

Does anyone know if this should be grounded immediately or is it waiting for some sort of input?

R1 is grounded by the ECU and it does so with KOEO "on contact" that is, the ground is there in the ECU, waiting.

But I wonder about the ground from the BSM for R2. Could it be that the BSM I ordered was faulty? I just see no other explanation.

I'll try opening one of the BSMs myself to see if I might find that circuit, or, manually ground it.

So unnecessarily complicated!!

[666ggj]

Hi Fareer
Did you every get to the bottom of your No ECU comms No crank.I ask as may van 2010 dispatch has the same problem. I have tried pretty much everythis even stripping back the looms under the bonnet to see if I could see anything strange, still nothing. Van still dead. Ecu sent off checked returned, Bsm replaced and under bonnet fuse box, and still its dead.

[Farseer]

Hi, unfortunately, I never got to the cause.

I sent the ECU to the same place it was first tampered with. Apparently, nothing was wrong with it... But ever since I got it back the car just started up and ran.

So either it will break down again OR the guy doing the ECU found something wrong with it and didn't tell me so as to not have to pay for anything.

Either way, I found out that on KOEO, there should only be one power feed to the ECU that is from fuse F1.

So, despite the way the power distribution is drawn, only F1 is the main ECU power with the key on engine off. The others are there only when the car is running. I suppose I should have come to that conclusion, as F10, when powered, also switches on the fuel pump. You shouldn't have a pump running when the key is just on.

Again, should have figured that out, but I am used to seeing multiple power feeds going to the ECU, most certainly not just one.

Very, very odd.

I wish you luck with yours. Is your engine the exact same as mine? Does something click at least from the BSM when you turn the key?