Airbag light on plus faulty passenger window

Hi All

I've just become a Citroen (C3) owner for the first time and registered to this forum. I am in need of some advice and I hope someone on this forum will be able to provide me with a solution.

I have a 2005 C3 HDi with the following issues:

Passenger side window will not operate
Airbag warning light is on (including the ligth which indicates the passenger side airbag is switched off

I'll give you a lowdown on what has been tried so far.

Passenger side Window - When I press the button to operate the window I can hear a clicking sound on the door. Therefore this indicated to me that there was an issue behind the door panel. So I took it to a friend who also has a C3 and is a former mechanic. He ended up taking the motor and circuit board out from the door panel and tested it in his car and both were working fine. This lead us to believe that there was no power coming through so faulty wiring/relay. However when we attached a voltage checker and operated the switch there seemed to be no issues with any voltage coming through. I think we were getting around 13v when we flicked the switch up/down.

Airbag Light - My friend went under the dash, under the seats and checked the connections and all seem to be fine. We checked the switch for switching the passenger side airbag on/off. When we switched it off the light came on around 5 seconds later. When we switched it on the lights came up 5 seconds earlier.

We did some research online which indicated a BSI reset was required. We attempted a reset as per the instructions on this forum but this did not seem to make any difference to anything.

We then checked all the fuses and all seem to be in working order.

My friend then plugged in his Citroen computer and we got the following readouts:

Permanent fault - Communication fault on the DATA wire with the engine relay unit

Fault permanent fault Fault: ECU internal (VAN interface) Not defined - Fault code: P1F4A

Fault permanent fault passenger's airbag deactivation Not defined - Fault code: P106F

He did try resetting the error codes but this did not solve the issues.

I'm hoping there is a Citroen expert on here who would be able to help out with this issue. Alternatively if someone could put me in touch with a Citreon specialist in the east London area I would be grateful.

Many thanks in advance for any help provided.

Thanks

Alal

Hi Alal

Alal wrote:Passenger side Window - When I press the button to operate the window I can hear a clicking sound on the door. Therefore this indicated to me that there was an issue behind the door panel. So I took it to a friend who also has a C3 and is a former mechanic. He ended up taking the motor and circuit board out from the door panel and tested it in his car and both were working fine. This lead us to believe that there was no power coming through so faulty wiring/relay. However when we attached a voltage checker and operated the switch there seemed to be no issues with any voltage coming through. I think we were getting around 13v when we flicked the switch up/down.

Can you swap switches over with the other C3?

Circuit it quite complicated, you need to follow the circuit from the Haynes manual for the C3 on eBay and check for continuity or test for voltages and compare with what the diagram shows.

Alal wrote: Fault permanent fault passenger's airbag deactivation Not defined - Fault code: P106F

Looks like you need that Citroen computer / Lexia tool from here to see that the airbag ECU and BSI is programmed correctly for the car.

'Not defined' suggests a mismatch between BSI programming and the actual car. Is this a replacement BSI, from a different car?

Alal wrote:He did try resetting the error codes but this did not solve the issues.

It wouldn't work unless the original problems that caused the errors were fixed. This is to be expected.


I guess you bought the car with these faults? can you contact the previous owner to find out about its history, particularly in regards to a replacement BSI/BSM.....

Thanks for the advice. Didn't think the window switch would be a problem. Will get that checked.

If the BSi was not configured to the car then surely it would throw off more error codes and issues?

I bought the car from a dealer who I am having issues with. Initially he told me the lights came on after he jump started the car and he would get it reset for me. However, he is now not answering any of my calls and when he does he fobs me off with this excuse or the other. Judging from the evidence I have seen inside the car he has attempted to fix it but has failed which is why he is avoiding me.

My friend has only acquired the Lexia software so he is a bit rusty with it. Would you be able to provide instructions on how to programme the BSI to the airbag ECU?

Thanks

Hi All

I have kind of left the above issues for a while because I couldn't get around to it. I've now managed to get an ex-Citroen mechanic to plug his computer on to my car and he has told me the following:

Airbag light - This is happening due to the airbag ecu being replaced (probably from a scrapyard) and not been configured to the car. He tells me that an airbag ecu can only be coded to one car therefore I have two options. Either to buy a new ecu from Citroen and they will code it to my car or to find someone who can take my existing one apart and re-code it. He wasn't sure if it could be done though.

Window Issue - He seems to think that everything is working in terms of electronics. The issue is the regulators which will need to replaced.

So my questions now would be:

1. Does anyone know of anyone who can code my existing airbag ecu to my car?
2. Would anyone be able to tell me where I could get second hand window regulators/how to work out the part number?

Thanks in Advance for any advice.

Kind Regards

Alal

Alal wrote:2. Would anyone be able to tell me where I could get second hand window regulators/how to work out the part number?

Have a look here and match it up with the similar year to your car (2002-2005
or 2006-2009), no need for part numbers.

Alal wrote:1. Does anyone know of anyone who can code my existing airbag ecu to my car?

This is normally a lexia job. I have not needed to do this, but adding modules to the BSI (like an ABS module) is usually only carried out by the lexia tool (maybe in 2 or 3 menus, not just one).

Our lexia topic is here: tips-for-any-citroen-c3-f8/lexia-and-ob ... -t655.html

Thanks C3 Guru. At least the window regulator doesn't seem too complicated.

I am aware of the lexia tool and diagbox. The guy who checked the car over has been a mechanic at Citroen for 15 years. He plugged in a diagbox computer to investigate the issues. He was quite sure that an airbag ecu box (once coded to a car) could not be recoded to a different car using lexia/diagbox. He was of the impression that the box needed taking apart and re-soldering or something along those lines. Any thoughts on this?

Alal wrote:He was quite sure that an airbag ecu box (once coded to a car) could not be recoded to a different car using lexia/diagbox.

OK. I have not had to move one of these from car to car, so I wouldn't say he was wrong. Its unlike all the other units in the car with the exception of the engine ecu which is locked to the BSI for security and can't be unlocked by lexia.

Alal wrote:He was of the impression that the box needed taking apart and re-soldering or something along those lines. Any thoughts on this?

Others have swapped BSI and engine ECU between cars (for a faulty BSI) and there has been no mention of having a problem with the Airbag ECU not communicating with the replacement BSI. I would be tempted to just buy a used Airbag ECU from ebay for less than £15 to prove yours a faulty/not faulty.

So I have finally got around to purchasing a window regulator and an airbag ECU off eBay as suggested in the post. I took it to a local mechanic and got the items replaced and we were still facing the same issues. I am inclined to think that this is a BSI issue rather than an actual issue with the airbag ECU and the window regulator.

Any thoughts on this?

Permanent fault - Communication fault on the DATA wire with the engine relay unit

Fault permanent fault Fault: ECU internal (VAN interface) Not defined - Fault code: P1F4A

Fault permanent fault passenger's airbag deactivation Not defined - Fault code: P106F

He did try resetting the error codes but this did not solve the issues.

Clearing the codes in not the way to fix the problem. You need to investigate the faults displayed and then fix them.

Use lexia to read errors in each of the affected ECUs, rather than just the BSI.

If there is suspicion that the BSI may not be the original one, it would be best to check for updates then reconfigure/check and adjust the configuration if any anomalies are found.

Alal wrote:I took it to a local mechanic and got the items replaced and we were still facing the same issues.

It would be helpful to read the codes again to see if they are the same, more or less faults and look at each of the effected ECUs for a better description of the codes.

Alal wrote:I am inclined to think that this is a BSI issue rather than an actual issue with the airbag ECU and the window regulator.

It could be.

So the guy hooked up the new regulator and flicked the window switch and there was no response. Checked the voltage going through to the switch and this was fine.

With the airbag ECU we were getting slightly different error codes from before. So the error codes prior to installing the new bits were as per my first post.

Fault permanent fault Fault: ECU internal (VAN interface) Not defined - Fault code: P1F4A

Fault permanent fault passenger's airbag deactivation Not defined - Fault code: P106F

We also got an additional error - P1027 - ECU Config - Not Defined - This may have appeared because the previous citroen mechanic switched something to do with the airbag off in order to try and remove the airbag light.

Once the new Airbag ECU was plugged in we got the following errors:

Fault permanent fault Fault: ECU internal (VAN interface) Not defined - Fault code: P1F4A

Fault permanent fault passenger's airbag deactivation Not defined - Fault code: P106F

So in effect the same errors.