SRS light on when right seat empty
02-24-2013, 11:50 PM
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SRS light on when right seat empty
Hello,
Recently i have the SRS light on when no one seats on the right chair. Also I notice that if I heat the right chair, after a few minutes it turns off again. It seems that the problem is with the occupancy sensor.
It has started when the temperature drops below 40s. Can it be that the sensor is malfunctioned in cold weather? Is there anything to do without replacing sensor (if it is the source of the problem).
I appreciate your answer.
Yos
Recently i have the SRS light on when no one seats on the right chair. Also I notice that if I heat the right chair, after a few minutes it turns off again. It seems that the problem is with the occupancy sensor.
It has started when the temperature drops below 40s. Can it be that the sensor is malfunctioned in cold weather? Is there anything to do without replacing sensor (if it is the source of the problem).
I appreciate your answer.
Yos
02-25-2013, 01:45 AM
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You could check the wiring and the connectors under the seat. If everything is fine, you would have to change the sensor mat. Be careful when working with the wiring, ignition off, key away from the ignition slot when inspecting the wires and unplugging connectors.
Welcome to the forum!
Welcome to the forum!
02-25-2013, 09:17 AM
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Thank you for your response.
I check the wires with the yellow case, and it seems fine to me.
The sensor pad seems to work when someone sits on it, so there is no safety issue here, and I don't think that it is necessary to replace the mat.
Also, without someone sits on the right seat, the SRS light is not always on. sometime it turns on only for a few minutes and then turn off again.
Can someone tell me how this thing works, can cold weather change the impedance which gives a wrong signal.
I saw in one of the posts that one used switch cleaner and it fixed the problem, https://mbworld.org/forums/m-class-w163/417691-srs-light-seat-occupancy-sensor.html
any suggestion?
I check the wires with the yellow case, and it seems fine to me.
The sensor pad seems to work when someone sits on it, so there is no safety issue here, and I don't think that it is necessary to replace the mat.
Also, without someone sits on the right seat, the SRS light is not always on. sometime it turns on only for a few minutes and then turn off again.
Can someone tell me how this thing works, can cold weather change the impedance which gives a wrong signal.
I saw in one of the posts that one used switch cleaner and it fixed the problem, https://mbworld.org/forums/m-class-w163/417691-srs-light-seat-occupancy-sensor.html
any suggestion?
02-26-2013, 02:04 AM
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Can you explain how did you conclude that there is no need to replace the mat if you already checked the wires and found them good (also at the area that is not visible)?
If a switch always works perfectly in the open position, it may still be a faulty switch if it sometimes fails to close properly.
Can you have the (SRS) fault codes read?
If a switch always works perfectly in the open position, it may still be a faulty switch if it sometimes fails to close properly.
Can you have the (SRS) fault codes read?
02-26-2013, 07:37 AM
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If i understood correctly, the job of the occupancy sensor, which is the source of this problem, is to identify if someone sits in the right seat, and to activate the air bags there in the case of accident.
When someone sits on the right seat, or if i put pressure there, it work fine, no light.
Also, if the light is on and i heat the chair, after two minutes it dissapears.
I check the wires only in the visible area. Before trying to remove the chair and looking on the hidden area, i am trying to understand the source of the problem.
I don't have the code, but based on what i wrote it seems from the occupancy sensor, going to the dealer, with the light off, probably will be useless, and since it turns off after a few minutes, i wont make it before the problem will dissapear.
Thanks.
When someone sits on the right seat, or if i put pressure there, it work fine, no light.
Also, if the light is on and i heat the chair, after two minutes it dissapears.
I check the wires only in the visible area. Before trying to remove the chair and looking on the hidden area, i am trying to understand the source of the problem.
I don't have the code, but based on what i wrote it seems from the occupancy sensor, going to the dealer, with the light off, probably will be useless, and since it turns off after a few minutes, i wont make it before the problem will dissapear.
Thanks.
02-27-2013, 04:15 AM
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The car records pretty much all problems, even many that have no indicator for the driver. The diagnosis tool can read stored codes in addition to current faults. This should help the workshop to identify the issue even if it was not present when the car is at the workshop.
Note that it is not sufficient for any sensor to work properly "in the active scenario", all sensors are monitored to be OK also in their other position(s). Now if the mat starts to misbehave, the signal does not seem to fit to the acceptable range when the seat is not occupied.
Note that it is not sufficient for any sensor to work properly "in the active scenario", all sensors are monitored to be OK also in their other position(s). Now if the mat starts to misbehave, the signal does not seem to fit to the acceptable range when the seat is not occupied.
