[sjuggins]

I think the noise is about 800Hz and is coming from more than one device. Apparently the noise dropped when the doser was unplugged but pulling the doser motor fuse made no difference. This suggests to me the noise is coming from the 5V supply.

Interesting. To me, the noise definitely sounded like it was coming from the doser as when I unplugged it definitely stopped. There are definitely 2 'sources' of noise in the engine, one from what appears to be right around the doser and another which I cannot pinpoint, where in my video I moved the camera over the top of the engine and you can hear another noise but it's not as loud.

I never thought (I'm no expert like you guys ) that it could be a 5v supply frequency making the noise.

Unplugging the fuses made zero difference which now makes sense, the actual doser connector/wire with 5v supply is likely still emitting that frequency which now cannot resonate and make an audible noise as not connected - have I interpreted that correctly?

 

[sjuggins]

Can I get you to test the voltage at pin 1 of the dosers connector relative to earth as shown below. If your multimeter has a frequency scale it would be worth seeing if it gives a reading.

There is a chance one sensor is overloading the 5V supply so check the doser pin 1 voltage I want you to try and disconnect every sensor with a 5V supply in turn and see if the noise stops. The camshaft sensor was reading the correct voltage so start with it. Then try any of the others I have listed.
Camshaft sensor 1115
Crankshaft sensor 1313
MAF sensor 1310
ERG 1297
Common fuel pressure sensor 1321
Accelerator pedal 1261
MAP sensor 1312

Thanks Ian. I did test Pin 1 relative to earth yesterday, I got 5v irrespective of the connector being plugged/unplugged or ignition on/off - makes sense based on the fuse pull doing nothing.

Can I just clarify what you want me to do is keep Pin 1 connected with earth on the meter and then go around unplugging the sensors you mention one by one noting the noise/frequency change (if meter supports)?

FYI - as mentioned in my post last night, following the Haynes Pro tests I did yesterday on the doser pins/voltage/resistance, it bizarrely no longer makes a noise but still reads 5v permanently as per my first line above.

The fact I couldn't get the motor valve to actuate by using Pins 3 & 4 with battery + & - led me to believe (as per the test conclusion) the doser needs replacing?

 

[Ian M Davis]

The way the doser works is it gets +12V from fuse 20 (Pin 4). The ECU will pull pin 3 to ground to activate the doser. When you applied voltage to th doser did you use the correct polarity - positive to pin 4 and pin 3 ground.

The four fuses you removed should not get any power until the car is cranked or running.

The 5V at the doser should be switch off when the ignition is off can you check that? If there is 5V there with the ignition off please check pin 5 (28V NR) of the fuse box again. It should also be 0V with the ignition off.

EDIT
BTW I think if the ECU is communicating and the car isn't cranking there is a fair chance the problem lies with the BSI or BSM.

 

[sjuggins]

Just finished doing the doser tests for you Ian - the EGR valve is where the other noise is coming from. As mentioned the doser itself no longer makes a noise.
I checked with Hz setting on my meter and got around 10-23hz when plugging the EGR sensor back in, I could fluctuate the noise up/down a little by moving the wires/sensor plug and this affected the Hz reading.

To confirm.
The doser unit/connector has 5v always - irrespective of the state of the ignition.

The way the doser works is it gets +12V from fuse 20 (Pin 4). The ECU will pull pin 3 to ground to activate the doser. When you applied voltage to th doser did you use the correct polarity - positive to pin 4 and pin 3 ground.

Yes, as per the tests Red shared - I did it both ways... Pin 4 to + and Pin 3 to - AND then as per the tests switched the leads also - both made no difference, the unit failed to activate.

EDIT
BTW I think if the ECU is communicating and the car isn't cranking there is a fair chance the problem lies with the BSI or BSM.

I know the BSM has previously been changed, in the past 3 years I believe, not to say it isn't faulty again.

 

[Ian M Davis]

Just finished doing the doser tests for you Ian - the EGR valve is where the other noise is coming from. As mentioned the doser itself no longer makes a noise.
I checked with Hz setting on my meter and got around 10-23hz when plugging the EGR sensor back in, I could fluctuate the noise up/down a little by moving the wires/sensor plug and this affected the Hz reading.

To confirm.
The doser unit/connector has 5v always - irrespective of the state of the ignition.



Yes, as per the tests Red shared - I did it both ways... Pin 4 to + and Pin 3 to - AND then as per the tests switched the leads also - both made no difference, the unit failed to activate.


I know the BSM has previously been changed, in the past 3 years I believe, not to say it isn't faulty again.

Okay there are some interesting results there. I don't know what to make of the 23Hz frequency but my main concern at the moment is why there is 5V at the doser sensor with the ignition off.
What should happen is when the ignition is turned on
(i) The ECU wakes
(ii) The ECU pulls pull pin 9 (28V NR) of the BSM to ground.
(ii) Relay R1.closes and supply 12V to the ECU via BSM pin 5 (28V NR)
It is worth checking pins 5 and 9 of the BSM 28V NR with the ignition off.

 

[Ian M Davis]

Given that the doser motor is not moving I wonder if the ECU is staying awake because the position sensor is detecting that the doser has not returned to the correct position.

It's interesting that the noise has come from the doser and ERG both have motor and a position sensor.

 

[sjuggins]

It is worth checking pins 5 and 9 of the BSM 28V NR with the ignition off.

Will do Ian, I think I’ve tried this before but will do so when home

 

[sjuggins]

Given that the doser motor is not moving I wonder if the ECU is staying awake because the position sensor is detecting that the doser has not returned to the correct position.

It's interesting that the noise has come from the doser and ERG both have motor and a position sensor.

I've had a quick Google and appears EGR's are commonly failing through being dirty - might be worth me stripping/cleaning it?
As for the doser motor - am I looking at a replacement? They're not much on eBay, £20-30 for a used one.

 

[sjuggins]

A couple of short videos of the relay noises, not sure if they're correct... thoughts?

The first clip is cycling the ignition on/off - battery is still connected at the end

The second clip is disconnecting the battery, you hear the relay close/de-energise?

- YouTube

Enjoy the videos and music you love, upload original content, and share it all with friends, family, and the world on YouTube.

youtube.com

 

[Ian M Davis]

I looked up a couple more diagrams so I thought I would post them. One is the fusebox circuit and the other is the starting wiring diagram.

I listened to the sound in the video of the relays clicking. The problem is more than one should turn on when the ignition is on. The R1 is of most importance because it is the master relay and it turns on when the ECU wakes. Three other relays are of interest:
R2 this turns on several things including the power to the doser motor but should on turn on when the car is cranked or if the engine is running.
R6 and R8 R6 needs to turn on when the ignition is on because it controls R8 which operates the starter motor.

I am not entirely sure how the doser motor works on your engine because the circuit doesn't allow for the polarity to change; one side of the motor is directly connected to the fuse box. The other side of the motor is connected to the ECU so all the ECU can do is vary the voltage but it can't reverse the direction of the motor. I therefore suspect the butterfly has a spring return.

I posted the starting wiring diagram because it shows that the ECU has very little involvement in the engine cranking. What should happen is when you turn the key to start relay R8 should close and power the starter motor solenoid. I have marked an image showing where the starter motor connects to the fuse box pin 2 (red wire) of 5V JN.. I see the fuse box has a yellow connector whereas the plug has the old style grey connector this would suggest the fuse box was changed at some stage. If you able to back probe pin 2 you should measure 12V when the key is turned to the the crank position.

EDIT

I did a bit of digging on the doser and this site gives some good images of it: Pillangószelep Új eredeti 0345E4 0345.E4 Citroen Peugeot

This discussion on the French Car Forum is interesting. While the doser they are discussing is quite different (vacuum operated instead of solenoid operated) it confirms that Peugeot do use dosers with a butterfly return spring. Your doser is more sophisticated than the one in the the discussion as it has feedback. If I am right the Haynes Pro test procedure is wrong. You need to keep the power connected because as soon as you disconnect the power the butterfly will spring back to its rest position. You should not reverse the polarity.

https://frenchcarforum.co.uk/forum/viewtopic.php?t=58705

 

[sjuggins]

I forgot to mention, I tested Pins 5 & 9 with the ignition off:
Pin 5 = 12v
Pin 9 = 0v

I posted the starting wiring diagram because it shows that the ECU has very little involvement in the engine cranking. What should happen is when you turn the key to start relay R8 should close and power the starter motor solenoid. I have marked an image showing where the starter motor connects to the fuse box pin 2 (red wire) of 5V JN.. I see the fuse box has a yellow connector whereas the plug has the old style grey connector this would suggest the fuse box was changed at some stage. If you able to back probe pin 2 you should measure 12V when the key is turned to the the crank position.

Thanks, Ian - yes, I was informed the BSM was replaced previously and I was wondering if is the right version/model. I watched a video on YouTube where a known working BSM didn't fix the problem as it was the wrong version. Once they put the right version/model in, it fixed the failed relay issue.
To be clear - I am not 100% on the component naming etc. by BSM, I am referring to the fuse box/sealed relay unit.

I will test Pin 2 for 12v when the ignition is turned to crank and report back.

Thanks for the additional wiring diagrams and additional research 👍

EDIT

I did a bit of digging on the doser and this site gives some good images of it: Pillangószelep Új eredeti 0345E4 0345.E4 Citroen Peugeot

This discussion on the French Car Forum is interesting. While the doser they are discussing is quite different (vacuum operated instead of solenoid operated) it confirms that Peugeot do use dosers with a butterfly return spring. Your doser is more sophisticated than the one in the the discussion as it has feedback. If I am right the Haynes Pro test procedure is wrong. You need to keep the power connected because as soon as you disconnect the power the butterfly will spring back to its rest position. You should not reverse the polarity.

https://frenchcarforum.co.uk/forum/viewtopic.php?t=58705

When I tested last night, I did not reverse the polarity. I also held the pins connected for several (5-6) seconds as well which is not shown in the video. All the doser ever did was make that click and when I released the power, click again. I'll have a read of the site you provided also.


I'm starting to think this now requires the BSM replacing if none of the relays are really working and can't be replaced. I'm just trying to fathom what could cause so many components to fail or behave improperly.

 

[Ian M Davis]

I forgot to mention, I tested Pins 5 & 9 with the ignition off:
Pin 5 = 12v
Pin 9 = 0v

That's the exact opposite of what should be happening. We need to find out why pin 9 is 0V. It could just indicate that the ECU is not shutting down but there could be a short circuit? What I suggest is:
(i) Unplug 28V NR from the BSM
(ii) unplug 48V NR (connector A) from the ECU
(iii) check if pin 9 has any continuity to earth

 

[sjuggins]

OK so a bit of progress, I think this morning...

The car is now cranking again!! The only thing I have done really (yesterday evening) is to remove the airbox and disconnect some sensors - MAF, EGR, and 2x fuel sensors (I believe) - the ones connected to a little fuel reservoir/pot next to the EGR. I was visually inspecting for bad wires so just making some space.

Results of some more tests this morning:

(i) Unplug 28V NR from the BSM
(ii) unplug 48V NR (connector A) from the ECU
(iii) check if pin 9 has any continuity to earth

No, Pin 9 does not have continuity to Earth - either after the battery is connected and all devices are asleep, after turning the ignition on/off, or after removing the 28V and 48V connectors.

I have marked an image showing where the starter motor connects to the fuse box pin 2 (red wire) of 5V JN.. I see the fuse box has a yellow connector whereas the plug has the old style grey connector this would suggest the fuse box was changed at some stage. If you able to back probe pin 2 you should measure 12V when the key is turned to the the crank position.

Back Probe Red Pin 2 (says pin 4 on connector - see pic) of 5V JN for 12v when the ignition is turned to crank and report back = 0v

So, I Back Probe White Pin (#2 according to connector) of 5V JN for 12v when the ignition is turned to crank and report back = 9v

During my research this morning, I came across the following post on another forum: Peugeot 308 2,0Hdi Starter not working [SOLVED]

I know this is for a 2.0 HDi but some of the symptoms were very similar and the wiring/pins appeared to be the same. I checked the connections (BSM Pin 16 28V GR (Grey) to ECU Pin A1 32V NR (Black) and I too have 10.62v with the ignition On rather than 12v. When I crank the engine, it drops to 0v. Returns back to 10.6v after cranking and drops to 0v with ignition off. For clarity - I back-probed the ECU connection as it was easy to test rather than remove the back of the BSM connector.

I have not done what the poster in that forum has done to fix his issue - I have only tested the volt reading as wanted to check back here first.

Is this related or am I going off on a wild goose chase?

As always, thanks for taking the time to help me figure this out, greatly appreciated.

 

[Ian M Davis]

BTW
BSM means Boîtier de Servitude Moteur (Motor Service Box). The letters "BSM" will be part of the engine fuse box part number.

OK so a bit of progress, I think this morning...

The car is now cranking again!! The only thing I have done really (yesterday evening) is to remove the airbox and disconnect some sensors - MAF, EGR, and 2x fuel sensors (I believe) - the ones connected to a little fuel reservoir/pot next to the EGR. I was visually inspecting for bad wires so just making some space.

Results of some more tests this morning:


No, Pin 9 does not have continuity to Earth - either after the battery is connected and all devices are asleep, after turning the ignition on/off, or after removing the 28V and 48V connectors.



Back Probe Red Pin 2 (says pin 4 on connector - see pic) of 5V JN for 12v when the ignition is turned to crank and report back = 0v
View attachment 109264

So, I Back Probe White Pin (#2 according to connector) of 5V JN for 12v when the ignition is turned to crank and report back = 9v

I double checked the wiring to the BSM 5 pin plug. In the diagram I looked at to determine the pin numbers pin 1 wasn't used but on other diagrams pin5 isn't used. Anyway I think the pin numbers on the connector are correct. Pin 4 is connected to the air-conditioner compressor. Good to hear the car is cranking again but I am surprised it is given that pin 2 only has 9V.

When you checked pin 9 did you check the cable or the fuse box? I wanted to check if the cable was shorting to earth but it occurred to me I wasn't clear.

I know this is for a 2.0 HDi but some of the symptoms were very similar and the wiring/pins appeared to be the same. I checked the connections (BSM Pin 16 28V GR (Grey) to ECU Pin A1 32V NR (Black) and I too have 10.62v with the ignition On rather than 12v. When I crank the engine, it drops to 0v. Returns back to 10.6v after cranking and drops to 0v with ignition off. For clarity - I back-probed the ECU connection as it was easy to test rather than remove the back of the BSM connector.

I have not done what the poster in that forum has done to fix his issue - I have only tested the volt reading as wanted to check back here first.

There is very little difference between BSMs. There are usually two manufactures and you may find some fuse boxes are missing some fuses and their connections. For example you may find BSM-1 to BSM-5. These are the same fuse box except BSM-1 has a full set of fuses whereas BSM-5 has several missing. If you buy an official spare for BSI-5 you would get a BSM-1.

Anyway you fuse box appears to have the same connection as the 2.0 HDi. The pins you were looking at connects to wire no 1021 "hands-free starting control" it and another wire from the BSI to the fuse box wire 7842 "remote control wake-up information" seem to have similar functions to wake the ECU so if you are finding an issue with wire 1021 I think you are on the right track.

 

[Ian M Davis]

Are you sure you are getting a proper battery connection to the fuse box. There should be a large cable from the battery to the fuse box. I have known the nut that clamps that cable to the fuse box to come loose and make a bad connection.

 

[sjuggins]

When you checked pin 9 did you check the cable or the fuse box? I wanted to check if the cable was shorting to earth but it occurred to me I wasn't clear.

I checked the connector by back-probing the connector, I did try the cable itself with my back-probe by piercing the cable and got the same result - I will triple check this again later.

There is very little difference between BSMs. There are usually two manufactures and you may find some fuse boxes are missing some fuses and their connections. For example you may find BSM-1 to BSM-5. These are the same fuse box except BSM-1 has a full set of fuses whereas BSM-5 has several missing. If you buy an official spare for BSI-5 you would get a BSM-1.

Anyway you fuse box appears to have the same connection as the 2.0 HDi. The pins you were looking at connects to wire no 1021 "hands-free starting control" it and another wire from the BSI to the fuse box wire 7842 "remote control wake-up information" seem to have similar functions to wake the ECU so if you are finding an issue with wire 1021 I think you are on the right track.

Do you think I should try the solution the person in the other forum I referenced did?

Are you sure you are getting a proper battery connection to the fuse box. There should be a large cable from the battery to the fuse box. I have known the nut that clamps that cable to the fuse box to come loose and make a bad connection.

99% sure as I actually removed the fuse box previously and made sure that nut was done up tight. I might take it off and clean the connections with some wire wool.

 

[Ian M Davis]

Do you think I should try the solution the person in the other forum I referenced did?

The problem is I don't understand what he did. In one line he is saying it should be 12V and the next he is saying he grounded it. It connects to a BSM processor input so I think it's okay to pull it to ground if you want to try.

 

[sjuggins]

The problem is I don't understand what he did. In one line he is saying it should be 12V and the next he is saying he grounded it. It connects to a BSM processor input so I think it's okay to pull it to ground if you want to try.

Agreed - I did struggle to follow exactly as well.

Also, the fact the crank sensor has weird voltage readings and the car is now cranking again (his wasn't) this solution is perhaps not as applicable.

 

[Ian M Davis]

Agreed - I did struggle to follow exactly as well.

Also, the fact the crank sensor has weird voltage readings and the car is now cranking again (his wasn't) this solution is perhaps not as applicable.

I think these lines operate on high level logic where logic 0 is near 0V and logic 1 near 12V. I suspect >10V should be seen as logic 1 so what he may be saying is it should be logic 0.

I think key thing is Pin 9 is 0V when the ignition is off. This means the is still awake when it should be in sleep mode so it make some sense there is a problem with that line. However, I wonder if something is keeping the ECU awake. For example if the doser or EGR are not going back to rest position the ECU may not sleep. One question when you initially connect the battery do you get the buzzing noise from EGR and doser or does it only start after to turn the ignition on.

 

[sjuggins]

One question when you initially connect the battery do you get the buzzing noise from EGR and doser or does it only start after to turn the ignition on.

Nothing happens until I turn the key. Even turning the side lights on (as per the battery connection process) initialises nothing - only turning the key, and then once the key is turned, they don't shutdown until the battery is disconnected.