06+ Passenger Weight Sensor with Race Seat Solved - Sort of
03-11-2016, 02:24 PM
#22
The problem with the pass side is it's an opds unit that communicates to the srs unit through either f-can or b-can I believe the drivers side is a resistance based though and I would think you could trick that like an air bag inflator with resistors
03-14-2016, 12:07 PM
#25
This thread makes me feel better about having an AP1....,
I did little research and it appears the OPDS unit takes readings from multiple weight sensors (2 or 4 weight sensors in the sensor base that the rails sit on, and maybe 1 or 2 in the seat-back), and reports back to the SRS system on readiness. If the SRS system powers up and the OPDS unit doesn't report readiness, it sets an SRS fault. Whether that only disables just the passenger air bag, or all air bags, is a separate subject.
From what I've read, once it sets a code, the OPDS unit will have to be re-initialized, even if you put everything back the way it was before you started. At this point, you'll have to take it to someone with an HDS unit to reinitialize it.
This is a suggestion based on what I've read about the systems. I'm not a Honda technician, but I've had experience in sensor calibrations and system diagnostics for industrial systems.
Before you take the OEM seats out perform the following tests;
1. Turn the key on, let the SRS system boot up and verify the SRS light is out.
2. Put a laptop, bowling ball, etc., in your passenger seat that will turn on the passenger "air bag off" light. Once you've verified that, set the item aside for later testing. If you want to get fancy, you can start piling stuff in the seat until the "air bag off" lights up and figure out the minimum weight needed to do it. You can then continue piling stuff in the seat until the light goes off again and determine the minimum passenger weight needed to make it work.
3. Disconnect the battery and check resistance on all the sensors with an empty OEM seat. You'll have to identify the wire pairs to each sensor, disconnect the plug from the OPDS unit and check resistance between each matching pair. Check with polarity in both directions in case they have diodes.
4. Take sensor resistance readings with the test item(s) you used before, in the OEM seat.
5. Take sensor resistance readings with someone sitting in the OEM seat.
You should now have a chart of resistance vs. weights from each sensor with an empty OEM seat, partial weights with "air bag off", and with a passenger (or objects) heavy enough to clear the "air bag off" light.
Now, if the system works the way I've read you can get started;
1. Make sure the key is off/battery disconnected, and stays off while you modify your aftermarket seat rails and seats to sit on the sensors, as described above. (Don't allow the SRS to boot up while components are removed)
2. When complete with installation, re-measure sensor resistance with the empty aftermarket seat installed. If the resistance is lower than before, you can add resistance in series to match it to OEM readings. If the resistance is higher, you'll have to put resistance in parallel with the sensors to match OEM readings. This step should match the baseline resistance for the empty aftermarket seat to be the same as for the empty OEM seat. If the sensors had diodes, your added resistors (only if in parallel) will also require diodes, to allow current flow in only one direction.
3. Check sensor resistance with the weight, then with the person in the seat. If the resistance vs. weight curves for the sensors are linear, the readings should be approximately same as the OEM readings.
4. Once you've verified the sensor readings are correct for the aftermarket seats, connect the harness to the OPDS unit, make sure the seat is empty, connect the battery and turn the key on, to boot up the system. The OPDS/SRS units shouldn't even see the difference.
5. If that works, you can re-run the previous tests to verify what weights turn on the "air bag off" light, and how much weight is needed to turn it off again.
I did little research and it appears the OPDS unit takes readings from multiple weight sensors (2 or 4 weight sensors in the sensor base that the rails sit on, and maybe 1 or 2 in the seat-back), and reports back to the SRS system on readiness. If the SRS system powers up and the OPDS unit doesn't report readiness, it sets an SRS fault. Whether that only disables just the passenger air bag, or all air bags, is a separate subject.
From what I've read, once it sets a code, the OPDS unit will have to be re-initialized, even if you put everything back the way it was before you started. At this point, you'll have to take it to someone with an HDS unit to reinitialize it.
This is a suggestion based on what I've read about the systems. I'm not a Honda technician, but I've had experience in sensor calibrations and system diagnostics for industrial systems.
Before you take the OEM seats out perform the following tests;
1. Turn the key on, let the SRS system boot up and verify the SRS light is out.
2. Put a laptop, bowling ball, etc., in your passenger seat that will turn on the passenger "air bag off" light. Once you've verified that, set the item aside for later testing. If you want to get fancy, you can start piling stuff in the seat until the "air bag off" lights up and figure out the minimum weight needed to do it. You can then continue piling stuff in the seat until the light goes off again and determine the minimum passenger weight needed to make it work.
3. Disconnect the battery and check resistance on all the sensors with an empty OEM seat. You'll have to identify the wire pairs to each sensor, disconnect the plug from the OPDS unit and check resistance between each matching pair. Check with polarity in both directions in case they have diodes.
4. Take sensor resistance readings with the test item(s) you used before, in the OEM seat.
5. Take sensor resistance readings with someone sitting in the OEM seat.
You should now have a chart of resistance vs. weights from each sensor with an empty OEM seat, partial weights with "air bag off", and with a passenger (or objects) heavy enough to clear the "air bag off" light.
Now, if the system works the way I've read you can get started;
1. Make sure the key is off/battery disconnected, and stays off while you modify your aftermarket seat rails and seats to sit on the sensors, as described above. (Don't allow the SRS to boot up while components are removed)
2. When complete with installation, re-measure sensor resistance with the empty aftermarket seat installed. If the resistance is lower than before, you can add resistance in series to match it to OEM readings. If the resistance is higher, you'll have to put resistance in parallel with the sensors to match OEM readings. This step should match the baseline resistance for the empty aftermarket seat to be the same as for the empty OEM seat. If the sensors had diodes, your added resistors (only if in parallel) will also require diodes, to allow current flow in only one direction.
3. Check sensor resistance with the weight, then with the person in the seat. If the resistance vs. weight curves for the sensors are linear, the readings should be approximately same as the OEM readings.
4. Once you've verified the sensor readings are correct for the aftermarket seats, connect the harness to the OPDS unit, make sure the seat is empty, connect the battery and turn the key on, to boot up the system. The OPDS/SRS units shouldn't even see the difference.
5. If that works, you can re-run the previous tests to verify what weights turn on the "air bag off" light, and how much weight is needed to turn it off again.
11-28-2016, 05:31 AM
#26
Bueller? Bueller? Anyone Solved This '06+ ABS Sensor Calibration?
I'm going to bump this forward eight months since it was resurrected earlier this year and the last post went through a great THEORY of how everything should work, could be tricked, or it MIGHT work based on reading.
I have accumulated a SPARE passenger '06+ seat rail with all sensors intact, have Planted fixed mounts, have a pair of nice BOTTOM MOUNT Recaros (could be an issue too, how do I get bolts in from bottom when welded to rails?) and I know a welder. I'm in the Balto/DC Metro area. I do NOT want to start down the road of destroying the parts I've got and getting more to destroy to weld up something if in the end, nobody has really ever finalized, calibrated, solved this painful issue. We '06+ folks must know we can install aftermarket seats and still have our airbag(s) working properly (not remove bulbs, not throwing codes) so we aren't driving around with airbags that won't go off if we hit something. I'm ready to go to my welder and have him figure out how to fabricate a mount for my seat to the spare '06+ rail with sensors but I need to know that it can be COMPLETED with the Honda calibration, etc.
The parts are expensive, ruining them and then doing the full install will get time-consuming and expensive and there are a lot of folks with '06+ who are really wanting to know this can be done properly and completed.
Bueller?
I have accumulated a SPARE passenger '06+ seat rail with all sensors intact, have Planted fixed mounts, have a pair of nice BOTTOM MOUNT Recaros (could be an issue too, how do I get bolts in from bottom when welded to rails?) and I know a welder. I'm in the Balto/DC Metro area. I do NOT want to start down the road of destroying the parts I've got and getting more to destroy to weld up something if in the end, nobody has really ever finalized, calibrated, solved this painful issue. We '06+ folks must know we can install aftermarket seats and still have our airbag(s) working properly (not remove bulbs, not throwing codes) so we aren't driving around with airbags that won't go off if we hit something. I'm ready to go to my welder and have him figure out how to fabricate a mount for my seat to the spare '06+ rail with sensors but I need to know that it can be COMPLETED with the Honda calibration, etc.
The parts are expensive, ruining them and then doing the full install will get time-consuming and expensive and there are a lot of folks with '06+ who are really wanting to know this can be done properly and completed.
Bueller?
11-28-2016, 07:55 AM
#27
Registered User
https://www.s2ki.com/forums/s2000-mo...ether-1027954/
Other than that thread, I haven't ever seen anyone claim success at this and unfortunately he hasn't posted since 08/13. I made up my mind to just pull my bulb this past weekend but the slight fight with the tabs that cover the screws above the cluster were just enough to deter me from going through with it. Replicating that threads steps may be the only hope to make that light go away and restore SRS functionality.
Other than that thread, I haven't ever seen anyone claim success at this and unfortunately he hasn't posted since 08/13. I made up my mind to just pull my bulb this past weekend but the slight fight with the tabs that cover the screws above the cluster were just enough to deter me from going through with it. Replicating that threads steps may be the only hope to make that light go away and restore SRS functionality.
11-28-2016, 04:02 PM
#28
I'm going to bump this forward eight months since it was resurrected earlier this year and the last post went through a great THEORY of how everything should work, could be tricked, or it MIGHT work based on reading.
I have accumulated a SPARE passenger '06+ seat rail with all sensors intact, have Planted fixed mounts, have a pair of nice BOTTOM MOUNT Recaros (could be an issue too, how do I get bolts in from bottom when welded to rails?) and I know a welder. I'm in the Balto/DC Metro area. I do NOT want to start down the road of destroying the parts I've got and getting more to destroy to weld up something if in the end, nobody has really ever finalized, calibrated, solved this painful issue. We '06+ folks must know we can install aftermarket seats and still have our airbag(s) working properly (not remove bulbs, not throwing codes) so we aren't driving around with airbags that won't go off if we hit something. I'm ready to go to my welder and have him figure out how to fabricate a mount for my seat to the spare '06+ rail with sensors but I need to know that it can be COMPLETED with the Honda calibration, etc.
The parts are expensive, ruining them and then doing the full install will get time-consuming and expensive and there are a lot of folks with '06+ who are really wanting to know this can be done properly and completed.
Bueller?
I have accumulated a SPARE passenger '06+ seat rail with all sensors intact, have Planted fixed mounts, have a pair of nice BOTTOM MOUNT Recaros (could be an issue too, how do I get bolts in from bottom when welded to rails?) and I know a welder. I'm in the Balto/DC Metro area. I do NOT want to start down the road of destroying the parts I've got and getting more to destroy to weld up something if in the end, nobody has really ever finalized, calibrated, solved this painful issue. We '06+ folks must know we can install aftermarket seats and still have our airbag(s) working properly (not remove bulbs, not throwing codes) so we aren't driving around with airbags that won't go off if we hit something. I'm ready to go to my welder and have him figure out how to fabricate a mount for my seat to the spare '06+ rail with sensors but I need to know that it can be COMPLETED with the Honda calibration, etc.
The parts are expensive, ruining them and then doing the full install will get time-consuming and expensive and there are a lot of folks with '06+ who are really wanting to know this can be done properly and completed.
Bueller?
11-30-2016, 07:04 PM
#29
Thanks for the compliment on my post! Unfortunately, no one has presented any factual information confirming they've been able to retain the AP2 functional SRS system sans faults with aftermarket seats. If mine was an AP2 with the seat sensors, I would consider testing it for the group, but it's not. That means "someone" is going to have to go through the steps I described to determine how the sensors react to weight changes. That testing can be done non-destructively, and will determine both if and/or how to work around the use of lighter seats while retaining normal SRS system function.
11-30-2016, 08:22 PM
#30
If the sensors are built into the rails, what's stopping us from just unbolting the seat, leaving all the oem stuff in the car unused? Basically having the oem rails just laying there for the sole purpose of making the car think there's an empty oem passenger seat still installed. Would this work? If someone can test removing their seat but leaving all the rails and sensors intact, I imagine this would be the solution. No need to hack up a hybrid oem/aftermarket rail, just have 2 (your choice of aftermarket installed and the oem loose).
Last edited by Grilla; 11-30-2016 at 08:24 PM.