B48 SRS code - not straightforward...

[breeze]

Car is a 2003 CLK55. A couples of years ago, I got an airbag code that was for a seat occupancy sensor. I bought a box of tricks to bypass the sensor, which came with another box to bypass the seatbelt sensor. Light reset and all fine.

More recently I had a sudden battery drain and loss of passenger seat electrical controls. Traced back to the seat control module, which I replaced with new. Seat controls fixed and no more battery drain. At some point between noticing the battery drain and replacing the seat control module, the airbag light came on.

Codes that appear immediately after a reset:

• B106C Fault in communication with component B48 (front passenger seat occupied and child seat recognition) or there is a cable fault.
• B106D The component or the signal line to the component B48 (front passenger seat occupied and child seat recognition) has short circuit to ground.

Code that shows after some time:

• B1002 Control module N2/7 (restraint systems control module (circuit 15R): No voltage present when voltage present at circuit 15.

My first thought was that the box of tricks had failed, so I replaced it. No change.

I am thinking that the wiring to the occupancy circuit has been damaged in some way, probably with me tugging at the wiring when checking the seat control module.

Thoughts? Is there anywhere obvious to check?

 

[breeze]

Embarrassing... this was a fuse.

Number 45, under the bonnet if anybody is curious. Must have blown after the initial diagnosis.

Hopefully related to the seat control module or occupancy sensor delete, both of which are now new.

Let’s see...

 

[mattkh]

Well done. I have learnt a lot from the thread.
Were these messages showing on the dashboard or a code reader..?
What is the W number for your motor..?

 

[breeze]

It’s a W209 CLK55 with an M113 engine.

There was a generic SRS message on the dash, I used an iCarsoft i980 code reader for codes.

After a bit of flapping around it looks like everything is sorted.

 

[mattkh]

It’s a W209 CLK55 with an M113 engine.

Thanks.

 

[ND85]

Car is a 2003 CLK55. A couples of years ago, I got an airbag code that was for a seat occupancy sensor. I bought a box of tricks to bypass the sensor, which came with another box to bypass the seatbelt sensor. Light reset and all fine.

More recently I had a sudden battery drain and loss of passenger seat electrical controls. Traced back to the seat control module, which I replaced with new. Seat controls fixed and no more battery drain. At some point between noticing the battery drain and replacing the seat control module, the airbag light came on.

Codes that appear immediately after a reset:

• B106C Fault in communication with component B48 (front passenger seat occupied and child seat recognition) or there is a cable fault.
• B106D The component or the signal line to the component B48 (front passenger seat occupied and child seat recognition) has short circuit to ground.

Code that shows after some time:

• B1002 Control module N2/7 (restraint systems control module (circuit 15R): No voltage present when voltage present at circuit 15.

My first thought was that the box of tricks had failed, so I replaced it. No change.

I am thinking that the wiring to the occupancy circuit has been damaged in some way, probably with me tugging at the wiring when checking the seat control module.

Thoughts? Is there anywhere obvious to check?

Hi,

I had the same issue and bought an emulator off eBay for my 2003 CLK, however now the seatbelt helper doesnt work, did you have that issue?

If not can you remember which emulator you bought

Thanks

 

[breeze]

Hi,

I had the same issue and bought an emulator off eBay for my 2003 CLK, however now the seatbelt helper doesnt work, did you have that issue?

If not can you remember which emulator you bought

Thanks

Yes, the helper no longer works. Passenger for me so not a big issue.