Replaced the sensor and the fault light is gone.

 

Hi,
Received my PP2000 yesterday. After a great struggle managed to install PP2000. Connected it to the car and there were a few faults. copied all the faults and cleared it. turned off the ignition and turned back on. Did the test again and guess what.......... AIR BAG ECU permanent fault right front satellite. (Driver side impact sensor)

I have seen posts by senior members here asking to replace both the sensors. I could see why. My humble explanation to this is due to the confusion in the terminology used by PP2000. Even for this fault, even though it says right front satellite, at another location PP2000 says Passenger side unit. This may be true for the Left hand drive vehicles, but not for the RH drives. Senior members please correct me if I am wrong.

In the mean time, my plan is to do a thorough wiring check between the Airbag ECU and the impact sensor. Also to source the impact sensors if it comes to replacement of them.

If any of you have solved this issue, please share your experience.
With regards,
Arun

 

Hi,
@Jim- thanks for the suggestions again.
Got the tools to remove the seat and tested the impact sensors. Just learned that the impact sensors are polarity sensitive. when connected one way it shows a resistance of 420 Kohms and the other way shows open circuit. Took a while to figure this out. Tested the other side and the same result. So back to square 1. Will have to do more research on how the sensors work to eliminate the possibility of both sensors failure (Unlikely situation). If anybody have tested a impact sensor please share your experience. I did try a higher resistance shunt to test the light but the light came back. I was afraid to put a lower resistance to test, as my understanding of the impact sensor is that the circuit inside the sensor will be complete in case of a crash and hence should give a low resistance.
As it stands now all the inputs and wiring into the ECU ( Airbag and the impact sensors) seems to be fine. Will have to test the wiring between the ECU and the BSI. Hope fully will get to do that over the weekend. Till then back to research and idea gathering. In the mean time any suggestions/ideas would be greatly appreciated.
Arun

 

Hi,
After a long debate decided to connect the meter the the Airbag ECU connector.
Precautions taken:
1. Battery disconnect procedure, 3 minutes rule. (Main battery and the fuse for service battery)
2. Meter negative lead connected with a resistor in series. (I used a 3.31 Kohms resistor)
3. Meter not connected for more that 10 secs for any reading.

Disconnected the Airbag ECU connector and did a resistance checks between various pins as per the wiring diagram. Airbags and seat belt pre-tensioners showed a value between 1 and 3 ohms. The two side impact sensors showed different resistor values. Pax side impact sensor showed 416 K ohms and the Drivers side showed OL. I guess the issue is Driver side impact sensor. Wanted to check the connector to the impact sensor but driver seat needs to be removed before I could access the impact sensor. Didn't have the tools to remove the seat but will get to it as soon as I can. Will keep you updated.

I had to admit that I was bit nervous to connect the meter to the airbags but was confident with my calculations and background research. None of the manufacturers recommend connecting the meter to the airbags. So if you are planning to connect the meter to the airbag do it at your own risk.

Reconnected the ECU connector, battery and the fuse. Did the BSI soft start procedure and the car is back to using condition.

Now the next step is to find a side impact sensor and replace it and hopefully it clears the Airbag light.
Arun

 

Hi Jim, Got your PM. I still can't send PM. Thanks for the sound advise:thumb:. It looks like I will have to get a PP2000 for myself. Here in Ireland it costs €50 for each diagnostic scan. Planning to order 1 from diagnostic world; Lexia 3 Citroen & Peugeot Planet 2000 (PP2000) Diagnostic Kit - Covers Airbag, ABS, Engine, Transmission & MORE

If you know any other place to get one cheaper and reliable, please let me know.
Thanks again.
Arun

 

I will have to get a PP2000 for myself. Here in Ireland it costs €50 for each diagnostic scan. Planning to order 1 from diagnostic world; Lexia 3 Citroen & Peugeot Planet 2000 (PP2000) Diagnostic Kit - Covers Airbag, ABS, Engine, Transmission & MORE

If you know any other place to get one cheaper and reliable, please let me know.
Thanks again.
Arun

Do a search of this site, there's a lot of (sometimes contradictory) information on where to get the planet box, and it IS worth getting one of your own (IMO).. The Stealers all want daft money just to run a 20 second scan. OK they have overheads, and probably even kids to feed :nod:

Cheers :thumb:
jim.

 

I have disconnected the main battery and the service battery before attempting anything on the airbag. I have also read and followed the safty procedures in the peugeot service manual.
The communication problem started before I did anything with the airbag system. So it is highly unlikely that I would have caused the issue.

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personally i would of disconnected the battery before even attempting the airbags :nono:

maybe that's where you went wrong with it first ???

 

I think the danger arises with resistance checks, that the nominal 3V on most ohmeters MAY detonate the squibs... even with both batteries off. :nono:

 

Thanks for that. I am waiting for a loan of the diagnostic tool. Once I get it I will see if the communication issue is sorted.
If I disconnect the airbag before connecting the meter what am I supposed to check. I do understand the risk of setting the airbag due to the meter voltage when doing the resistance measurement, but I have seen a you tube video which shows connecting the meter directly to the airbag and testing the resistance. I was thinking of connecting a resistor in series with the meter and measuring the resistance of the squibs. Hope to do this over the weekend. Thanks again for the input. Hope to get more.
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I'm no expert but the first thing I'd try to sort out is the ecu communication. The way it seems to me is that the BSI is the central controller managing communication between all the cars systems & ECU's. If the BSI cannot communicate with the airbag ECU then it will quite rightly display the airbag light & warnings. You have replaced the ECU but more importantly, you haven't confirmed that communication with the replacement ECU is taking place. Untill you establish communication you're going nowhere fast.

You've established power & ground but haven't confirmed any data lines are good. You will need to disconnect airbags before metering out any loom to a bag as the voltage on the meter could potentially cause the airbag to activate.