Airbag trigger unit Cayenne S 4,5 l V8

[Alexander Tobiasson]

 

 

 

 

 

 

Has now changed airbag trigger unit (box) with no results. I have changed everything in the manual for error code 1738. New airbag tendons, new airbag triggering unit box. But my airbag light will remain illuminated. I have tried to zero the system with PIWIS. Unfortunately, my intuition told from the beginning that the error is in a ground fault. I have spent one year at this error and give up now. The car does not go through the Swedish survey and I have now immobilize the car. I will not be able to sell the car even with this problem. I feel very distressed and dejected ...

 

Have you checked the grounds on the seat belt buckles?  They are well known for ground related faults.

 

No, this was new information for me. Where can I find it / them ???

 

 

The seat belt buckles, the part that the shoulder harness plugs into, have wires running to them that tell the system when the seat belts are buckled and turn off the seat belt alert chimes.  They also help tell the air bag system which seats are occupied in case of a crash, as well as controlling the system pre-tensioners.  If the buckles get dirt in them, they often do not register properly and the air bag system declares a fault.

 

 

Sometimes, but not always, just cleaning out the buckles with some electrical contact cleaner will solve the issue, other times the buckle and/or wiring harness need to be replaced as wear has broken the circuit.

 

I have tried to clean but it does not help. I have noticed that the warning lamp for the "safety belt" is not lit when driving without a seat belt. The warning light does not indicate when starting the car. I have never seen the light shine sometime?

 

 

It is sounding more like you have a buckle or wiring  issue, you should get an indication and/or a audio alarm of some sort if you try driving without the seat belt.

 

I get no sound or indicator in the display. Neither the driver side or passenger side. The lamp has never shone in my possession of the car. You advise me to change Buckel seat?

 

[JFP in PA]

 

 

 

 

 

 

 

Has now changed airbag trigger unit (box) with no results. I have changed everything in the manual for error code 1738. New airbag tendons, new airbag triggering unit box. But my airbag light will remain illuminated. I have tried to zero the system with PIWIS. Unfortunately, my intuition told from the beginning that the error is in a ground fault. I have spent one year at this error and give up now. The car does not go through the Swedish survey and I have now immobilize the car. I will not be able to sell the car even with this problem. I feel very distressed and dejected ...

 

Have you checked the grounds on the seat belt buckles?  They are well known for ground related faults.

 

No, this was new information for me. Where can I find it / them ???

 

 

The seat belt buckles, the part that the shoulder harness plugs into, have wires running to them that tell the system when the seat belts are buckled and turn off the seat belt alert chimes.  They also help tell the air bag system which seats are occupied in case of a crash, as well as controlling the system pre-tensioners.  If the buckles get dirt in them, they often do not register properly and the air bag system declares a fault.

 

 

Sometimes, but not always, just cleaning out the buckles with some electrical contact cleaner will solve the issue, other times the buckle and/or wiring harness need to be replaced as wear has broken the circuit.

 

I have tried to clean but it does not help. I have noticed that the warning lamp for the "safety belt" is not lit when driving without a seat belt. The warning light does not indicate when starting the car. I have never seen the light shine sometime?

 

 

It is sounding more like you have a buckle or wiring  issue, you should get an indication and/or a audio alarm of some sort if you try driving without the seat belt.

 

I get no sound or indicator in the display. Neither the driver side or passenger side. The lamp has never shone in my possession of the car. You advise me to change Buckel seat?

 

 

 

No, I am advising you to do some diagnostics to find out why the car does not sense that you are driving it with the seat belts undone.  The buckle is just one component in this system that needs to be tested either electrically or using a Porsche specific scan tool.  Besides the buckles, there are also weight sensors in the seat cushion's that sense when someone sits in the seat.  Something in this network of contacts (in the buckles) and sensors is obviously not functioning correctly.  Are you sure someone has not disconnected something in the system before you purchased the car, which is why none of the alerts are set off when you drive without seatbelts?  If you go back to Loren's post on the meaning of the code you are seeing, it looks like something is not connected or misconnected.

[Alexander Tobiasson]

 

 

 

 

 

 

 

 

Has now changed airbag trigger unit (box) with no results. I have changed everything in the manual for error code 1738. New airbag tendons, new airbag triggering unit box. But my airbag light will remain illuminated. I have tried to zero the system with PIWIS. Unfortunately, my intuition told from the beginning that the error is in a ground fault. I have spent one year at this error and give up now. The car does not go through the Swedish survey and I have now immobilize the car. I will not be able to sell the car even with this problem. I feel very distressed and dejected ...

 

Have you checked the grounds on the seat belt buckles?  They are well known for ground related faults.

 

No, this was new information for me. Where can I find it / them ???

 

 

The seat belt buckles, the part that the shoulder harness plugs into, have wires running to them that tell the system when the seat belts are buckled and turn off the seat belt alert chimes.  They also help tell the air bag system which seats are occupied in case of a crash, as well as controlling the system pre-tensioners.  If the buckles get dirt in them, they often do not register properly and the air bag system declares a fault.

 

 

Sometimes, but not always, just cleaning out the buckles with some electrical contact cleaner will solve the issue, other times the buckle and/or wiring harness need to be replaced as wear has broken the circuit.

 

I have tried to clean but it does not help. I have noticed that the warning lamp for the "safety belt" is not lit when driving without a seat belt. The warning light does not indicate when starting the car. I have never seen the light shine sometime?

 

 

It is sounding more like you have a buckle or wiring  issue, you should get an indication and/or a audio alarm of some sort if you try driving without the seat belt.

 

I get no sound or indicator in the display. Neither the driver side or passenger side. The lamp has never shone in my possession of the car. You advise me to change Buckel seat?

 

 

 

No, I am advising you to do some diagnostics to find out why the car does not sense that you are driving it with the seat belts undone.  The buckle is just one component in this system that needs to be tested either electrically or using a Porsche specific scan tool.  Besides the buckles, there are also weight sensors in the seat cushion's that sense when someone sits in the seat.  Something in this network of contacts (in the buckles) and sensors is obviously not functioning correctly.  Are you sure someone has not disconnected something in the system before you purchased the car, which is why none of the alerts are set off when you drive without seatbelts?  If you go back to Loren's post on the meaning of the code you are seeing, it looks like something is not connected or misconnected.

 

Hello again. Everything started when I had error code 1217 Ignition circuit power's side

airbag. * airbag warning light on * Driver's side airbag can not be triggered.

This I solved by soldering the cables. A recognized common error in the Porsche Cayenne. I zeroed the car with PIWIS and everything worked. After one month began Airbag light shine again and we linked up the car and made a new diagnosis. Then there were only error code 1738 Airbag Sensor (operates's) * airbag warning light on

* Driver's airbag can not be triggered.

This code I have now enjoyed for over 1 year without finding fault. I have no other fault codes in the airbag system. When Porsche workshop in Sweden trying to zero the system with PIWIS so it only takes half a second to illuminate the airbag lamp again. so of course I support your theory that there is a short circuit somewhere.

FAULT CODE 1738

The airbag sensor (DRIVER'S)

Diagnostic conditions

* On Ignition

* Internal function test on the airbag triggering unit.Possible Cause of fault

* Implausible signal (incorrect airbag sensor Installed)

* Open circuit (based on wiring between the airbag triggering unit and the air bag sensor or the airbag sensor itself)

* Electrical fault in electric circuit (based on wiring between the airbag triggering unit and airbag sensor;

probably a short circuit to B + or a short circuit to ground)

* Faulty (airbag sensor is faulty)

* Airbag triggering unit faulty

There are 6 steps in how to troubleshoot the fault. I followed the steps and measured the cables between the airbag sensor (drives) to the airbag triggering unit and cables are intact.

[Alexander Tobiasson]

Are there any error codes indicating that the belt is out of order?

[JFP in PA]

Are there any error codes indicating that the belt is out of order?

 

The codes you might see are not specific to the belts, only that the airbag system is faulty.

[Alexander Tobiasson]

Thanks for your reply. Unfortunately I have lost hope and do not know what I'm going to do with the car. I have tried to fix the error for over 1 year!