Citroen Relay 2006 Immobiliser Padlock

[Dieseljimmer]

I have recently purchased a very clean, low mileage, 2007 (2006 build) Citroen Relay camper conversion. It has been running and done 1000 miles of trouble-free motoring over the summer months.
After being sat on the drive for the last 4 weeks (It was unlocked during this time) I went to move it and it would not fire. When I realised it was not going to fire, I noticed the padlock on the instrument cluster had not extinguished and realised this was the reason for the non-starting. I thought a reset may have been needed by way of central locking via the key fob, no central locking function! Central locking function did not return until I disconnected the battery, central locking then returned via the key fob. Unfortunately, the battery disconnection did not resolve the padlock issue and non-fire. I have 2 remote fobs and have used both with no change. I have replaced fob batteries also.
After plug-in, using my Delphi software, codes read as follows: -
ECU: -
D700 Unknown code (Will not reset)
Permanent
C426 Unknown code (This will reset but returns when the ignition is switch on)
Permanent
BSI: -
D600 Engine immobiliser
Problem detected during transmission of unlock code.
Permanent (This will reset but returns when the ignition is switch on)
D701 No communication with ECU
Permanent (Will not reset)
D706 ABS/ESP Communication faulty
Permanent (Will not reset)

One thing I did notice; the Delphi software has an eOBD function, when I attempted to connect it fails and throws up a fault in the BSI D601 C – Line error. This does reset though.

Work carried out to remedy with no success clearing the above codes: -
Gearbox to chassis earth strap cleaned (New ordered, on BO).
Under bonnet fuse box split and terminals clean internally. Some corrosion but nothing major.
Wire harness visually checked behind o/s/f headlamp, no damage/abrasion visible.
ECU terminals checked for corrosion, plugs removed and checked (Clean, nothing visible).
Battery positive post fuses checked, and terminations cleaned
BSI plug connectors/fuses checked, all sound and clean.
BSI wiring harnesses visually checked no damage or abrasions.

I have now reached the extent of my diagnostic understanding without the use of wiring diagrams for input/output voltages, pin “out” identification and wire tracing, any help with this would be greatly received.

If I am going to keep the van for any length of time and get confident with the reliability I want to fully understand the electrical systems and have the ability to fault find and successfully rectify faults when/if they arise in the future, even if it means purchasing the Lexia 3 for interrogating electronic faults.

Many thanks

[wheeler]

Firstly we need to determine which model of Relay you have, a mk2 or a mk3? I would have thought a 2006 model should be a mk2 but there is a bit of confusion as you refer to a BSI which would only be fitted to a mk3 onwards. Your VIN can confirm what you have.
Next do you have a note of your electronic code? it should be on a card like below (ignore the Fiat bit)?
If so you can use this code to override the immobiliser to check there is nothing else wrong & its just an immobiliser issue.

[Dieseljimmer]

Morning All,

Hi wheeler,
Thanks for the quick response! I do have the security card, I've attached a picture. (I couldn't see your attachment) It has a 5 digit code. I've heard everyone talk of a 4 digit codes!? I have another piece of card with Fiat on it, which is 4 digit but looks like the radio code, lol!

I've tried depressing the throttle, when turn the ignition on, but it doesn't activate any light flashing, or have I got it wrong?

VIN is as follows :- VF7**************[VIN obfuscated, can be read by forum staff]

Cheers.

[wheeler]

OK so you have a mk3 Relay but it was built right at the end of 2006 so its actually the mk3 model.
This is the correct code card, this is a Fiat system so uses a 5 digit pin code for the immobiliser not a 4 digit like Citroen/Peugeot.
Im not 100% that the emergengy start procedure still works on the mk3 but you can test it. Note its the engine management light that flashes, not the padlock lamp.
1. Press and hold down the accelerator pedal and switch on the ignition.

2. When the diagnostic lamp goes out release the accelerator pedal, the lamp will start
to flash.

3. Count the flashes and when the first number of the code is reached press and hold
down the accelerator pedal again.

4. Wait for the lamp to go out again, then repeat step 3 for all five digits of the code.

5. After the last digit, hold down the accelerator pedal until the lamp goes out then
release the pedal. The engine should now start when cranked.

[Dieseljimmer]

Hi wheeler,

Thanks for the steer and sharing your knowledge!

Ah, right, I was looking at the padlock not the engine management symbol when depressing the throttle !!

I'll give it a go first thing tomorrow morning and report back.

Once again, many thanks!

Cheers
Jim

PS I've order the Lexia software from Easydiagnostic's, hopefully banish the kiss of death I seem to have with Citroen's

[Dieseljimmer]

Hi Wheeler,

The emergency start procedure hasn't worked. I kept the throttle pedal down for at least a minute, tried it a couple of times, nothing.

The padlock light comes on after about 10sec, I thought the sequence is on first, check key, all good, light off, start engine?

The Lexia kit has arrived this morning (Shout out the Easy Diagnostic's for a fast delivery!!) I'll set it up and look to plug-in.

Cheers.

[wheeler]

Does the engine management light not go out after around 10 seconds? Like i said i have never done this on a mk3 Relay but it certainly works on a mk2.
I would have thought that if the remotes were working then they keys were matched but will be interesting to see what Diagbox says first.
Depending on what it says you can look at trying to re code the keys as you have the code, when doing this you must program all the keys you have at the same time or the keys will become scrap.

[Dieseljimmer]

Further update on this

See screen shot from Diagbox

No Comms from ECU back to the BSI via the CAN!

Looks like I need to check the CAN wiring/plug from the ECU?!

[Dieseljimmer]

What voltage is normally on the CAN High and CAN Low at idle, and what pins on the OBD plug are they normally assigned to?

I can check what I have then. Traced the twisted pair to the ECU, pin A4 and B4 if I'm correct!?

Cheers.

[wheeler]

Pins 6 & 14 of the OBD socket normally CAN lines.
The resistance across the CAN H & L should be 60 ohms.
The voltage on each should be 2.5v each. Its not always like this in reality though but the voltage on each should add up to 5v so you sometimes get 3v on one & 2 on the other.
I dont know the ecu pinouts off hand but just be aware twisted pair doesn’t necessarily mean its the CAN lines. There can be a few things twisted pair like injectors for example are normally twisted pair wiring.

[Dieseljimmer]

Nice one, thanks for that! I'll check the readings.

Its the only twisted pair going to the ECU associated with the main harness route (Centre plug), it runs to the ABS plug from there (Same colours, although not sure this is always true!?) up the main harness. I've checked all the wires to the point they travel across under the window scuttle panel. Apart from being a bit dusty with entrained dirt nothing really jumps out. I've heard terminal pins to plug connector spades can be a problematic!

I think I'm going to have to see about a wiring diagram with ECU pin outs next!? Are there member here who have access to wiring diagrams or is Service Box?

Once again, thanks for your help!

[Hell Razor5543]

The colours may not be the same throughout their length. It is not unknown for them to change colour mid length (for example, when going via a plug/socket at a bulkhead). However, there will be a code printed at regular intervals (every few inches) that will remain constant along the full length.

[Dieseljimmer]

@Hell Razer5543

Ah, right, that's helpful, I'll bear in mind, Cheers!

[Dieseljimmer]

Latest update!

Resistance across Pins 6 & 14 - Open circuit

At idle Pin 6 = 0.5v awake Pin 6 = 0.21v
14 = 11.21v 14 = 4.81v

Battery Voltage 12.47v

Idle values don't change even when the vehicle is centrally locked and left for some time. Clearly nothing happening on Pin 6, is it likely there is a short to earth somewhere? Or am I barking up the wrong tree?

I can believe this has happen whilst the vehicle has been stood for the last 4/5 weeks!!

I'm at a bit of a loss, any thoughts greatly received, cheers.

[Dieseljimmer]

I've had a further look as this with my Scope to confirm my numbers and findings ion the last message.

See the attached!

I don't appear to be able to get the 11.44v off the CAN high at idle. The Scope1 attachment shows sharp peaks whereas the Scope2 shows an overview!

Where is the CAN signal generated? Have I got a goosed BSI?

I've also attached some of the fault descriptions from the ECU and BSI.

Cheers.