wiring help please

[paullap]

Hi, I have a Peugeot 206 2005 1.4 petrol no start no crank situation, I have spent along time checking power and earths fuses ect, No communication with the ecu. so no fault codes.

So yesterday I decided to have another go, I got my old trusty £5 test light out, Negative to the negative battery terminal and started by checking all the fuses, all are good, and now working in the bm34 unit under the bonnet, I thought I would check to see where I have power, Back probing the connectors, when I got to the Black far left connector, A very thin Blue wire, No chance of getting the number on it as it is so small. as I back probed it , a lot of clicking going on around the engine, So holding the test light on this wire, I got my mate to turn the car over , and it started, several times, but as soon as I remove my tester it cuts out.

before I go too far stripping the loom to see where the wire goes, Does anyone know what that left connector is for.

The other thing, when holding the test light on the back of that blue wire, the test light lights up, not bright, but it lights up. I don't understand why. if the test light was giving something a good earth it would not light up, but could it be that I am switching something on by earthling it out making it live?. like negative earth switching?.


if some can throw some light on this, It would be appreciated.


Paul

[ekjdm14]

If the light was in fact giving something a good earth it would light up (albeit dimly as described) depending on how much current the said something is trying to draw... (the 12v+ (or maybe 5v+) makes its way from battery +, through said component/s (maybe the BSM or BSI) and down their earth wire to the test lamp & then through the lamp to earth.

How do the rest of the cars systems behave, do you have dash lights/radio/wipers etc with ignition on, does the remote locking work, lights on warning beeper etc as that would maybe help pin down where the fault lies. Also, is the battery fully charged and known good? Dodgy batteries can cause havoc with BSI function.

[paullap]

Hi The dash lights all work, but they do go out after about a minute, I will check tomorrow to see if the lights/wipers/radio, work. do you know what this connector is for?.

If this is BCM connector, Are we thinking bad earth on the BCM, or an internal fault in the BCM?.

Link below
Paul

[wheeler]

Hi, I have a Peugeot 206 2005 1.4 petrol no start no crank situation

Im confused, your previous post says it is cranking ? Do we have the starter cranking or not ?
When you earth the wire are you getting comms with the ECU ?
What is the pin number of where the wire is in the 16 way black connector ?

[paullap]

Sorry for the confusion, \it does not crank or start until I connect my test light to pin 13 on Black connector PM1 Noir .


I will have to check to see if I get comms with the screwdriver/test light connected.


Thanks for taking an interest


Paul

[paullap]

Just done a quick read with Planet, Holding the screwdriver on pin 13m, I can communicate with the ecu, No faults on the ecu
but abs or ESP ecu permanent fault . absence of communication with the engine management ecu. operating fault/


I am not sure if this helps


Paul

[beelim]

I would go with a bad earth connection . the diagram attached shows pin 13 on the right side (the black connector) as being the earth from a relay and probably more than one ie fuel pump relay too.

[beelim]

Here is what pin 13 affects

[paullap]

Hi Thanks again, So where do I start to find this bad earth?. could it be a bad fuel pum relay?. I havent managed to find the pump relay yet. can you tell me from your diagram the earth pins to check. I will see if I can find the earthing points on the car.


Thanks again


Paul

[beelim]

No need to find the fuel pump relay as all of the relays are sealed together in a unit. The fact that they are all not working and do work when you jump the earth connection says that a bad earth is the problem. The earth cable will come from this sealed box of relays. It looks like this and the relays are inside it. Check the earth wire coming from this. Ie disconnect and clean it.

[paullap]

Thats brilliant help, I will do it 1st thing in the morning, I will let you know How i get on.


Many thanks for taking ther time and effort


Paul

[ekjdm14]

Hope this provides a solution, although if cleaning the connection doesn't help perhaps a quick & dirty solution could be to add your own new earth from the blue wire to the battery negative. (would be a last ditch effort though as I'm unsure how it would affect the car's ability to "sleep" when switched off and may need a switch to stop it flattening the battery when not in use).

Here's hoping that a clean of the proper earth wire does the trick though

[paullap]

Ok , I have had a good look at this unit. Taken it out of its housing , no obvious earth cable nothiomng earthing close, all the wires go in to several looms. can you give me any pin nubers or some clue as to where to look for the earths please.


Regards


Paul

[beelim]

Hi Paul, If you look at the picture above of the BSM , above the number 10 is a silver earth where the bolt goes through to hold the part to the body. That's what you need to clean up.

[furriegurrie]

Are you sure? On my Pluriel the maxi fuses are connected to that and it's 12 volts I believe .....

I agree it looks like an earth, but it is not