Citroen Relay 2022 airbag codes

[Kazzian]

I replaced the double passenger and drivers seat on my Citroen Relay 2022 van. It only has a driver's airbag. I didn't turn the ignition on during the change over. I swopped the pretensioner over to the new seat and the seat belt stalks from the outer passenger seat with the wired seat belt buckle. The seat harnesses were disconnected for a few weeks during the seat replacement however I believe I have connected the harnesses correctly. I now have fault codes. B0129, B0136,B0137.
The pretensioner shows a value of 1.7 ohms and the drivers air bag 2.7 ohms. Can anyone help with the error code meaning? My diagnostic box with the latest online updates will not erase the codes. . Does it need to be plugged into an OE Digibox or have I introduced 3 faults to my air bag circuit that I can't identify? All advice would be greatly appreciated.

[PaulC5]

This link gives definitions for the B codes, they might not be exact for your vehicle but they suggest wiring faults. Possibly the faults are due to something in the replacement seat - why not put the old seat back and see if the faults go. https://radmanrepair.ca/generic-vehicle ... 100-b0199/


B0129 – Seatbelt Buckle Switch LH Circuit Malfunction
causes: Faulty seatbelt buckle switch, wiring or connector.
B0136 – Seatbelt Pretensioner Squib Circuit Open
causes: Open circuit, faulty seatbelt pretensioner, wiring or connector.
B0137 – Seatbelt Pretensioner Squib Circuit Short to Battery
causes: Short circuit, faulty seatbelt pretensioner, wiring.

[Kazzian]

Thank you for the codes. Update... I decided to stop my conversion work and concentrate on diagnosing the cause of the fault codes. Armed with a note pad, Foxwell Auto Master pro diagnostic machine and a box of resistors of different values, I connected the Foxwell and bought up the fault codes. I had also bought dedicated resistors with pins that plug into the yellow harness plugs. However these proved by a tedious process of elimination to be the wrong values for what I needed. B0136 and B0137 are passenger seat occupancy sensors. 0.5 ohms resistors fitted allowed me to erase those codes, that left me with B0129 passenger seat belt buckle faulty, After countless attempts I found that a 1k resistor linking the orange and black wires on the disconnected yellow plug under the passenger seat turned off the airbag warning light. Eureka!! Hallelujah!! Note...I didn't have to erase the code, the light went out after I fitted the last resistor. However I did of course use my Foxwell machine to erase the code from the ECU. Fingers crossed all will be good for it's first MOT.

[PaulC5]

Putting resistors in, does it mean the airbag system will not work as intended ?

[wheeler]

Firstly you should NEVER put an ohmmeter on an airbag or pre tensioner. An ohmmeter sends out a small current to do its measurement, this can in some cases be enough to deploy the airbag.

Putting resistors in, does it mean the airbag system will not work as intended ?

Im assuming the resistors are only in place for the components now missing due to the single passenger seat conversion?
If this is the case the rest of the system should work as normal.

[Kazzian]

I didn't take the passenger seat occupancy sensors out of the old seats before selling them. I bought some new eBay seat sensors but they didn't fool the air bag ECU so I fitted resistors that the ECU liked...note, too higher resistor values turns on the seat belt warning light. Just passed it's first MOT so all good.