Reset Occupancy Detection Sensor (ODS) via Subaru SSM?

[Brock31]

I suppose I'm looking for input from a specialist in this department.

Airbag light came on for no reason.

Tried the "resistor fix" with no success.

A friend works at the local dealership, so I have access to the SSM scanner.

There are services out there that supposedly can "reset" or repair the ODS module but only if the vehicle has been in an accident. Mine has not.

I have found instructions that appear to give directions on how to reset the module. https://www.shopempiresubaru.com/how...bag-module.htm but don't know if they are relavent to MY '08 STi

I've checked the wiring harnesses and connections under both seats, cleaned connectors, cleaned seatbelt buckles/connectors etc..

Took my car over to the dealership the other day and had the codes scanned again. (I had just replugged the connectors back in prior to the scan)
5 DTC's read:

-2C Belt tension sensor failure
-29 ODS Failure
-37 Buckle switch RH failure
-27 ODS communication error
-41 Side airbag RH failure

Supposedly the buckle and belt tension DTC's is directly related to the ODS failure.

Does anybody know of the procedure to reset the ODS module using SSM3?

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[Elbert Bass]

Originally Posted by Brock31

I suppose I'm looking for input from a specialist in this department.

Airbag light came on for no reason.

Tried the "resistor fix" with no success.

A friend works at the local dealership, so I have access to the SSM scanner.

There are services out there that supposedly can "reset" or repair the ODS module but only if the vehicle has been in an accident. Mine has not.

I have found instructions that appear to give directions on how to reset the module. https://www.shopempiresubaru.com/how...bag-module.htm but don't know if they are relavent to MY '08 STi

I've checked the wiring harnesses and connections under both seats, cleaned connectors, cleaned seatbelt buckles/connectors etc..

Took my car over to the dealership the other day and had the codes scanned again. (I had just replugged the connectors back in prior to the scan)
5 DTC's read:

-2C Belt tension sensor failure
-29 ODS Failure
-37 Buckle switch RH failure
-27 ODS communication error
-41 Side airbag RH failure

Supposedly the buckle and belt tension DTC's is directly related to the ODS failure.

Does anybody know of the procedure to reset the ODS module using SSM3?

The fact that you had all that unplugged right before the scan will cause most EVERY code you have and gives you NO useful information.

First thing is try to clear codes. Next is perform the ODS Re-Zero procedure exactly as detailed in the FSM for you model. Your friend works at the dealer so they should have no trouble looking up the manual - even downloading a copy for you.

I forget the exact details but the seat and seatback have to be in a certain position, and maybe even the seatbelt plugged in. If that doesn't work you will either replace the ODS module and/or the whole seat bottom - and re-zero again.

Have your friend check the TSB's and Tech Tips. Also have him run you VIN for open recalls. There was a problem with some of those seat bottoms/modules (I forget years/models affected) and there was a TSB or recall. If your car is not a salvage title you may get some help from Subaru.

If your friend at the dealer has access to SSM then he should have access to STIS (or whatever they call it now) with all the correct information you need.
Oh Yeah - you can re-zero the ODS anytime. You rezero anytime the seat is removed or any work is done to the seat - aint nuthin special.

[Brock31]

Thank you sir for the information!

When I made this post, I was hoping you’d respond!
I’ve read many of your other posts and they are very detailed, specific and useful.
I’m assuming you either are or were in the Subaru technical field on a professional level.

[Brock31]

So, I went by the dealership last week. All the plugs had been in place since my last post. 3-4 weeks. Battery had not been disconnected or anything.

SSM showed the same error codes. SSM would not allow the codes to be cleared.

I downloaded the FSM on ODS Diagnostics. Followed the procedure to attempt to re-zero the ODS. Manual says it takes a while, but the recalibration just froze. Sat there and watched it for like 25 minutes spinning. My buddy said it was likely because the Codes were all still present and the SSM didn't like trying to re-calibrate with active Trouble Codes.

The FSM listed a bunch of diagnostic tools to check resistance and capacitance of the sensor etc...but they all seem to have the same resolution. Replace seat bottom.

~$1300 is crazy to have to replace the entire seat bottom.

Why is the SSM not able to clear the codes?

[Elbert Bass]

Originally Posted by Brock31

So, I went by the dealership last week. All the plugs had been in place since my last post. 3-4 weeks. Battery had not been disconnected or anything.

SSM showed the same error codes. SSM would not allow the codes to be cleared.

I downloaded the FSM on ODS Diagnostics. Followed the procedure to attempt to re-zero the ODS. Manual says it takes a while, but the recalibration just froze. Sat there and watched it for like 25 minutes spinning. My buddy said it was likely because the Codes were all still present and the SSM didn't like trying to re-calibrate with active Trouble Codes.

The FSM listed a bunch of diagnostic tools to check resistance and capacitance of the sensor etc...but they all seem to have the same resolution. Replace seat bottom.

~$1300 is crazy to have to replace the entire seat bottom.

Why is the SSM not able to clear the codes?

You have a hard fault in the module under the seat or the "mat" has failed. I have no answer other than than if I ever had one with codes and they would not clear or calibrate Subaru had us put the seat bottom in. It was always warranty - usually someone spilled something on the seat.

I found this link
https://www.myairbags.com/product/su...44hzYKbPPtdnF7

I have not used the service, have no information about this service but if you are absolutely sure the seat bottom has not gotten wet it would be worth a try.

Here's a little theory: Most passenger ODS system used strain gauges that measure weight built into the frame. That way it knows the size person in the seat and fires (or not) the passenger front air bag accordingly (the passenger front bag has a two stage igniter).
Your car has a capacitive system that was supose to be more accurate (cheaper to build). It measures body mass based on capacitance. Works fine until you spill a drink or sit on the seat with wet clothing. For liability purposes Subaru insists replacing the seat bottom as an assembly for repair.

[Brock31]

Originally Posted by Elbert Bass

You have a hard fault in the module under the seat or the "mat" has failed. I have no answer other than than if I ever had one with codes and they would not clear or calibrate Subaru had us put the seat bottom in. It was always warranty - usually someone spilled something on the seat.

I found this link
https://www.myairbags.com/product/su...44hzYKbPPtdnF7

I have not used the service, have no information about this service but if you are absolutely sure the seat bottom has not gotten wet it would be worth a try.

Here's a little theory: Most passenger ODS system used strain gauges that measure weight built into the frame. That way it knows the size person in the seat and fires (or not) the passenger front air bag accordingly (the passenger front bag has a two stage igniter).
Your car has a capacitive system that was supose to be more accurate (cheaper to build). It measures body mass based on capacitance. Works fine until you spill a drink or sit on the seat with wet clothing. For liability purposes Subaru insists replacing the seat bottom as an assembly for repair.

Thank you for the reply!

So, that was exactly my first course of action….to research avenues to potential repair the ODS. The system looks to be 2 parts. The sensor itself, or the seat mat and the ODS module, the box under the seat.

MyAirBags was my first attempt. I contacted them after researching what their services offered and read many, MANy suspect reviews. Once I finally did make contact with them, I was able to confirm with some confidence that their service was only available to systems that the vehicle had been in an accident. When I explained my situation, they told me their service would not work……for whatever reason. That avenue didn’t seem worthwhile to pursue.

With the thought that maybe the module itself may be the issue, I have contacted a member here on Nasioc that has an ODS module he’d sell me for $60. I haven’t pulled the trigger on that because I wanted to exhaust my options to reset the system, which have been unsuccessful.

Everything I’ve read and been told about ODS failures involve the seat having gotten wet. The day the light came on, I can say with confidence that the seat was not wet. It had not gotten wet recently either. The car is 17 years old, so I can say it has probably gotten wet before, but not near the time when the light came on.

Do you think buying a different ODS module would be a worthwhile experiment?

[Elbert Bass]

Originally Posted by Brock31

Thank you for the reply!

-SNIP-
Do you think buying a different ODS module would be a worthwhile experiment?

Can't say for certain. My EE side (I was studying towards an electronics degree when I got sidetrack into automotive in the seventies) says no since the theory that makes the system work is like a tuned radio circuit. But if you want to absorb the $60 on the off chance you save buying a seat...

[Brock31]

My gut feeling is that since the fault codes are specific to the sensor (the mat) that replacing the sensor module would not work.

So, back to one of my original "fix' ideas: the resistor.

Since people have been swapping in ODS-less seats for forever and getting the airbag light off by using the 3.3 ohm resistor, why wouldn't it work in my situation?

Would the ODS module have to be unplugged for the resistor mod to work?

Does anybody know which exact holes in the plugs the resistor is to be installed?

I've researched and watched more YT vids than I care to count...

[Charlie-III]

If you don't care about the sensor, you don't want to make it work, doing nothing only trips the dash light. A failure should NOT fail any state inspection since it's not emissions related.
You could do the "$0.05 fix", a piece of opaque tape over the light on the dash.

[Brock31]

Originally Posted by Charlie-III

If you don't care about the sensor, you don't want to make it work, doing nothing only trips the dash light. A failure should NOT fail any state inspection since it's not emissions related.
You could do the "$0.05 fix", a piece of opaque tape over the light on the dash.

Lol…yeah. I could go that route. Cracking open the cluster and getting into the dash is kind of a pita too.

[Brock31]

Bumping this in the hopes that someone has run into this issue.

Since I can't post pictures, I have a couple of threads over at IWSTI with pics of the underseat plugs in question.

https://www.iwsti.com/threads/airbag...t#post-4553360

https://www.iwsti.com/threads/airbag...t#post-4547443

[stoich68912]

Last I dealt with airbag codes/light I recall that if the airbag light is on some or all the airbags could be disabled in the event of a crash. Not sure if that applies to the codes you are dealing with, but FYI if you go the route of ignoring it.