Porsche Airbag Systems

Also from Issue 179

  • Porsche at the Monterey Historics
  • Keep the Faith: Cool Beige 356 Outlaw
  • Interview: Brian Redman
  • First Drive: 2010 911 Turbo
  • Dig Deep: One-Owner 356 Speedster
  • 1,953-pound 911 SC
  • GT3 Cup-powered 1976 911
  • Market Update: 928
  • Icon: 908/02
  • 2010 911 Sport Classic
  • Project 914 3.6: Paint!
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Porsche Airbag Systems 1
Porsche Airbag Systems 2
The 1987 U.S. 944 Turbo was the first Porsche and the first vehicle to feature dual airbags as standard equipment.
Porsche Airbag Systems 3
A 964-based 911 undergoes crash testing.
By 1990, Porsche made dual airbags standard equipment in all models. Top to bottom: 944, 964-based 911, and 928.

That said, a passive approach to air­bag maintenance is not a good idea. Por­sche says airbag systems should be inspected per the factory repair manual recommendations four years after a car’s build date. The system should again be inspected eight years after manufacture and then every two years thereafter for the life of the car. These inspections should be recorded in the maintenance manual, including a listing of any repairs or replacement of system components.

In addition to periodic inspections, the following components must be replaced after a deployment in the early cars: the control unit, both front impact sensors, the contact unit on the steering-column switch, and the airbag units. In later cars, check the repair manual carefully for what must be replaced in the event of a deployment. Por­sche wants to learn from airbag deployments, asking that the parts be returned for inspection via a Porsche dealer. This includes any system components that malfunctioned.

Generally, airbag system inspections are not automatic; you must request one. Unfortunately, most owners rarely proactively pursue inspecting this system as part of their maintenance program. So what’s involved in a periodic inspection? First, airbag warning light function is verified. If a fault is induced by interrupting power either to or within the system at a specific point (this varies by model), the control system must recognize, record, and playback the fault both on the airbag light and by outputing a fault code to a factory diagnostic tool.

Once the fault is corrected and a technician clears the fault, the system must accept the command, erase the fault memory, and return to normal operation. Next, a visual check of all system components ensures no physical damage or modifications have taken place that will hinder or prevent airbag deployment. All wiring must be in good condition and wiring connections must be tight and free of corrosion. No wiring that could induce electric current should be placed in the proximity of an airbag harness.

The best short-term insight into the operational condition of your airbag system is to monitor the airbag light on the dash. When you start your car, the airbag light should illuminate for about three to five seconds and then go off. If the air­bag light does not come on or turn off (at all) and/or the light illuminates after the initial startup sequence, there is a problem/fault in the system that must be diagnosed and repaired.

When troubleshooting the system, the use of a factory diagnostic tool is recommended — or at least one designed to interface with the systems of the Por­sche in question. Similarly, a technician experienced with the system will be best able to ensure that an accurate diagnosis is obtained. The problem may be simple (like a bad sensor in a seatbelt buckle) or complex (like wiring or a control unit that has failed).

While it’s easy to ignore the airbags as a Porsche ages, we believe the proactive approach recommended by Porsche is the best way to maintain longterm functionality. Your life may depend on it.

Some of the technical information used in this article is copyrighted by and used with permission of Porsche Cars North America. Pictures, diagrams, and tables are by the authors unless noted. Have technical questions? Please contact us at: techforum@excellence-mag.com

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