# Passenger Seat Airbag Sensor Interference



## carbon02 (Feb 25, 2011)

As part of my heated seat install I removed the passenger seat from the car, and the bottom seat cushion from the passenger frame. 

Either the passenger presence sensor itself is bad, or the connection from where the sensor plugs into the airbag module that sits under the seat is not tight and all the way seated. 

I really believe the sensor is activated based on pressure, as I've had computers and XM radios sitting on it and haven't had a problem.

Check out my How-To for the heated seats in my signature. There are some pictures of the sensor up on the shutterfly site. 

If you're still under the bumper to bumper warranty then the dealer should fix this. I don't think the sensor would come off the seat pad all that easily, and you may need a seat pad and a sensor. 

Good Luck


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## WX4WTF (Oct 23, 2012)

I've had the PPS replaced once already by my dealer and this is when they said they are sensitive to EMI from electronics. I'm sure they are activated by pressure, but obviously there is some issue with interference causing the airbag control module to flake out and throw a warning.

Point is, even after having the seat sensor replaced, i should be able to use a laptop in my lap without risking my life on the road.

EDIT: I'm almost wondering if i lay down a sheet or two of aluminum foil in the seat if it would keep this from happening. If that worked, i could permanently install a layer of it under the seat cover between the cover and cushion to keep the system from failing.


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## JerTM (Dec 12, 2014)

Directly from Service Information. So an electronic device that makes a strong enough EMI could confuse the module. Yeah, it could suck for a select few but over the course of 7 years I have only encountered this once. It was a laptop directly on the seat of a vehicle.

"The Passenger Presence System transmits and receives a low-level electric field. The measured capacitance value of this field is used to determine the type of occupant sitting in the front passenger seat. If the measured capacitance is less than a calibrated value, then the Passenger Presence System module will send a serial data signal to the Inflatable Restraint Sensing and Diagnostic Module to disable the passenger instrument panel air bag. If the measured capacitance is greater than a calibrated value, then the passenger presence module will send a serial data signal to the Inflatable Restraint Sensing and Diagnostic Module to enable the passenger instrument panel air bag. The Inflatable Restraint Sensing and Diagnostic Module will notify the customer of the enable/disable status by illuminating one of the PASSENGER AIR BAG ON/OFF indicator. The passenger presence module monitors itself for faults and will displays diagnostic trouble codes (DTCs) on the scan tool. When a fault is detected, the passenger presence module sends out a message to the Inflatable Restraint Sensing and Diagnostic Module. The Inflatable Restraint Sensing and Diagnostic Module responds by sending a command message to the Instrument Cluster to illuminate the AIR BAG indicator. "


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## ChevyMgr (Oct 27, 2010)

And here is what the bulletin states:



#12-09-41-002B: Passenger Presence System (PPS) May Command Seat Belt Reminder Chime and Passenger Airbag Indicator On When Electronic Devices or Conductive Objects are Placed on Front Passenger Seat - (Jul 23, 2014) 




Subject: Passenger Presence System (PPS) May Command Seat Belt Reminder Chime and Passenger Airbag Indicator On When Electronic Devices or Conductive Objects are Placed on Front Passenger Seat Models: 2012-2015 Buick Verano
 2013-2015 Buick Enclave, LaCrosse, Regal 2013-2015 Cadillac ATS, CTS, SRX, XTS 2014 Cadillac ELR 2012-2015 Chevrolet Cruze 2013-2015 Chevrolet Equinox, Malibu, Traverse, Volt 2014-2015 Chevrolet Impala, Impala Limited, Caprice PPV, SS 2013-2015 GMC Acadia, Terrain 
[HR][/HR] 

[HR][/HR]Some customers may comment about 5 slow chimes, with no obvious reason. If the customer would check the PPS display, they would notice the passenger seat belt indicator is illuminated. 
Dealers should be aware that when certain conductive objects are placed on the front passenger seat, the front passenger airbag indicator may illuminate. The seat belt reminder light/chime may also be activated. 
Examples of objects that could enable the airbag include:


Computers, Electronic Tablets
Charging and Audio Cables
Cell Phones
Tech 2®
Large Container of Liquid
Groceries
An electronic device does not necessarily need to be turned on to cause this condition.
Because this vehicle is equipped with low risk passenger airbags, the PPS system is designed to turn the airbag on for most front seat occupants and turn the airbag off for small children in child seats. The system works by detecting the capacitance of the object on the seat, not the objects weight; and certain conductive objects will enable the airbag. The passenger seat belt reminder system is active when the passenger airbag is on.


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## carbon02 (Feb 25, 2011)

JerTM & ChevyMGR-

I really like to understand the theory of Automotive technology. Thanks for posting what you did. My mind is still trying to figure out how the surface of my but as a passenger can Interfere with an electric field! Wow technology!

This makes me wonder how the GM factory heated seats work when they are applied to a seat with this sensor. I knew by just looking at the "fabric looking sensor" applied with adhesive to the seat foam bottom, that installing anything over it could be risky. If a computer causes problems, a 30 watt heated seat pad definitely would! 

Thanks guys for your input! Another somewhat obscure Cruze fact for the memory!


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## WX4WTF (Oct 23, 2012)

Chevymgr, I think you misread my original post. My problem is not that the car is asking me to fasten the seat belt. My problem is that sitting in the passenger seat using a laptop computer causes the "SERVICE AIRBAG" DIC warning as well as an airbag light on the cluster, not the airbag light by the passenger seat. This in turn means that in the event of a crash, at minimum the passenger airbag will not deploy, at maximum, the entire system will fail to deploy.

I realize there's a little confusion, and everyone has put a bag of groceries in the passenger seat heavy enough to make the car think there's a human sitting there, but this is not what I'm describing. I'm describing a fundamental engineering flaw in the airbag system that has to potential to cause loss of life. 
You as well as JerTM seem to think its unusual for a passenger in a GM vehicle to be using an electronic device while riding in the car. it's 2015, everyone has a cellphone in their pocket, and its not at all unlikely that a strong enough EMI field could wreak havoc with these faulty or overly sensitive seat sensors that GM is installing. I'm a broadcast engineer specializing in RF transmission technologies for broadcast television, i know how electrical interference can cause problems.

As a side note, I'm surprised that the GM customer service account hasn't commented on this. Usually they are one of the first offering to assist...

I hope it doesnt take 10+ years for GM to act on this like it did with the ignition switch defect.


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## JerTM (Dec 12, 2014)

I'm not confused at all about passengers using electronics. I simply said that in the years I have been doing this, I have only come across one person that had this concern. Having said that, use your "knowledge" and come up with a repair, or just keep complaining about it on a car forum, your choice.


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