Replaced ECU, BSI and new key. Sill not starting, RAC says no comms from diagnostic port. Possible wiring issue.

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suavegarve
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Joined: 31 Dec 2020, 01:26

Replaced ECU, BSI and new key. Sill not starting, RAC says no comms from diagnostic port. Possible wiring issue.

Post by suavegarve »

206 1.1 2005

Anyone get any ideas on which wires could be causing this problem.

I replaced the ECU, BSI and key as the car was not starting. However, I still have the same problem, and garage and RAC are not able to get anything from the diagnostic port.

wheeler
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Joined: 21 Sep 2002, 19:07
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Re: Replaced ECU, BSI and new key. Sill not starting, RAC says no comms from diagnostic port. Possible wiring issue.

Post by wheeler »

Im afraid your going to have to give a bit more info/details/history on the problem to get any help with this.
Do you have a power supply & earth at the diag port?
What did you think the problem was to replace the ECU & BSI?
Is the engine turning over? is the dash showing anti theft/immobiliser fault?
Is the ECU powering up? Are you getting 5v & 12v feeds at your sensors?
What are the last 8 digits of the VIN?

Peter.N.
Donor 2020
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Re: Replaced ECU, BSI and new key. Sill not starting, RAC says no comms from diagnostic port. Possible wiring issue.

Post by Peter.N. »

I had a similar problem with my first 406 estate, it was due to water ingress. Sadly I found it was cheaper and a lot less hassle to replace the car with another 406 estate which I did for £400. Had several after that no problems, I think they must have been the best car Peugeot made.

It had done in excess of 50k miles so for what I paid for it I still had good value.

Peter

suavegarve
Posts: 10
Joined: 31 Dec 2020, 01:26

Re: Replaced ECU, BSI and new key. Sill not starting, RAC says no comms from diagnostic port. Possible wiring issue.

Post by suavegarve »

Do you have a power supply & earth at the diag port?
I don't know how to test that

What did you think the problem was to replace the ECU & BSI?
RAC came out as the car was turning over and not starting. They said no power to fuel pump but fuel pump was functional. Could not get any diagnostic connection so suggested loose wire or faulty ECU. Garage also said same thing. So I took a chance and replaced those parts but still same thing.

Is the engine turning over?
Engine is turning over fine. RAC also sprayed some fuel into the engine but it would not catch.

Is the dash showing anti theft/immobiliser fault?
Eco mode showing on screen.

Is the ECU powering up? Are you getting 5v & 12v feeds at your sensors?
Don't know how to check that.

What are the last 8 digits of the VIN?
44377323

I have access to a multi meter if that helps with testing.

Thanks for the help so far.

wheeler
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Joined: 21 Sep 2002, 19:07
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Re: Replaced ECU, BSI and new key. Sill not starting, RAC says no comms from diagnostic port. Possible wiring issue.

Post by wheeler »

No power to the fuel pump & it sounds like the ECU is not powering up, my first thoughts would be an under bonnet fusebox fault.
Disconnect the coolant temperature sensor & connect your multimeter across the 2 terminals & switch ignition on, are you getting 5 volts?
Eco mode is not a fault, its a power saving feature, the car will come out of eco mode when the engine is started.

suavegarve
Posts: 10
Joined: 31 Dec 2020, 01:26

Re: Replaced ECU, BSI and new key. Sill not starting, RAC says no comms from diagnostic port. Possible wiring issue.

Post by suavegarve »

Assuming I'm using the tool correctly and it's the correct sensor, I'm getting 0.089

Images attached.
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wheeler
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Joined: 21 Sep 2002, 19:07
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Re: Replaced ECU, BSI and new key. Sill not starting, RAC says no comms from diagnostic port. Possible wiring issue.

Post by wheeler »

Assuming the ignition is switched on then it looks like the ECU is not powered up. The most likely culprit is the under bonnet fusebox. Next step is to check the power supplies & earths to the ECU.
I’ll have a look at a diagram.

wheeler
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Joined: 21 Sep 2002, 19:07
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Re: Replaced ECU, BSI and new key. Sill not starting, RAC says no comms from diagnostic port. Possible wiring issue.

Post by wheeler »

OK, Check for ignition live supplies on pin 12 of the 16 way green connector o the under bonnet fuse box and pin 8 of the 16 way black connector
If you have no power at pin 12 of the 16 way green check for power at fuse 4.

suavegarve
Posts: 10
Joined: 31 Dec 2020, 01:26

Re: Replaced ECU, BSI and new key. Sill not starting, RAC says no comms from diagnostic port. Possible wiring issue.

Post by suavegarve »

Do I need to remove the connector to test it?

Do I test the connector, or the pins on the fuse box?

Do I use my multi meter for this?

wheeler
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Joined: 21 Sep 2002, 19:07
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Re: Replaced ECU, BSI and new key. Sill not starting, RAC says no comms from diagnostic port. Possible wiring issue.

Post by wheeler »

suavegarve wrote:
02 Jan 2021, 23:15
Do I need to remove the connector to test it?

Do I test the connector, or the pins on the fuse box?

Do I use my multi meter for this?
Leave the plugs connected

Probe into the contact on the plug, where the wire comes out

Yes, set to volts

suavegarve
Posts: 10
Joined: 31 Dec 2020, 01:26

Re: Replaced ECU, BSI and new key. Sill not starting, RAC says no comms from diagnostic port. Possible wiring issue.

Post by suavegarve »

I have power on the green connector but nothing on black connector

wheeler
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Joined: 21 Sep 2002, 19:07
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Re: Replaced ECU, BSI and new key. Sill not starting, RAC says no comms from diagnostic port. Possible wiring issue.

Post by wheeler »

Can you recheck the black plug again but when the engine is cranking

suavegarve
Posts: 10
Joined: 31 Dec 2020, 01:26

Re: Replaced ECU, BSI and new key. Sill not starting, RAC says no comms from diagnostic port. Possible wiring issue.

Post by suavegarve »

Tried while cranking and still nothing (well it showed something like 0.7)

wheeler
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Joined: 21 Sep 2002, 19:07
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Re: Replaced ECU, BSI and new key. Sill not starting, RAC says no comms from diagnostic port. Possible wiring issue.

Post by wheeler »

OK Pin 8 is supplied by an internal relay in the fusebox & supplies power to the ECU, assuming that you have confirmed all the fuses are ok then I would say based on perevious experience the fusebox is at fault. You would need to get a bit more involved checking wiring going between the ECU & fusebox to confirm 100% but the fuseboxes are a fairly common failure. The good news is they are not coded so a second hand one can be used but it needs to be from a same spec vehicle.

citroenxm
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Re: Replaced ECU, BSI and new key. Sill not starting, RAC says no comms from diagnostic port. Possible wiring issue.

Post by citroenxm »

Have you looked at the bsm fuse box under the bonnet
We have a 207 sw 1.6 hdi.. 179k always started. It has sat a month or so waiting for mot I went out to start it at first do starter turning after flicking the key a few times the starter woke up but wasnt functioning properly. Then after a bit more it did but the engine only spun over.. this has never happened anyway. I opened up the fuse box. Took plugs out and found some lovely corrosion in one of the sockets. I tried to clean it up penetrating oil. Put the plugs back in car started and ran but pas and abs faults came up.. took plug back out broke some pins from corrosion...

Anyway. Found an identical one fitted it car perfect..
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