Airbag fault code 1738

[Alexander Tobiasson]

Hey. I'm new to this forum and owner of a Cayenne S V8 2004., I have had error code 1217 and remedied this by soldering the cables, everything worked fine for 1 month. Now I have received error code 1738 sensor for airbag (driver), and seat occupancy, passanger - too big and Resistance battery open circuit. Are there more connections under the driver's seat that can cause a short circuit? I can not delete the error code ... it comes back right away?

All the best / Alex from Sweden

[Loren]

Fault code 1738 -- Airbag sensor (driver's)

Possible cause of fault

- Implausible signal (incorrect airbag sensor installed)

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

- Electrical fault in electric circuit (based on wiring between 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

[Alexander Tobiasson]

Hello Mr Porsche.-)

Appreciate With respect your answer but possible errors are taken from Porsche's 2003-08 Restraints Airbag - 9pa_Cayenne PDF format, and the text is hard to understand and interpret without pictures, I was wondering if anyone here on the forum have experience with similar error code and any image in the plug or airbag sensor to facilitate my visual inspection under the driver's seat. Have a long way to a porsche dealer. But I am now out of the garage and lift the seat and make a visual inspection ..... anyone know where the airbag sensor is located?

With respect Alex (Sweden)

[Loren]

There are multiple airbag sensors installed -- you are going to need a Porsche PST2 or Porsche PIWIS tester to further diagnose this airbag error to the correct sensor. All further testing/troubleshooting requires the Porsche tester -- sorry.

Plus there are precautions you will need to understand and take before working near "live" airbags.

[Alexander Tobiasson]

**** so sad ... I have Autel Maxidas Ds708 which is a pretty advanced diagnostic tools. Apparently this is not enough tools?

[Alexander Tobiasson]

The problem with the airbag light started when the flashing and sometimes loose it and sometimes it was off ... this went on for almost one week every day ... it could blink and alert on the display 50 times at 1-mile drive .... the problem could then be gone for a couple of days then it came back and star to blink ... Now warn and light is constant.

Alex

[simonbarc1975]

Try www.porschecable.com or google Porsche cable.    I’ve ordered this in the past, it looks like a gen 1 durametric cable and does the trick without paying over the odds prices.   It is compatible with version 4 or 5 of the software  and also comes with software download link which and does the job and is an inexpensive way of getting the job done as has saved me a fortune.     Hope this helps.

Simon

[JFP in PA]

Try www.porschecable.com or google Porsche cable.    I’ve ordered this in the past, it looks like a gen 1 durametric cable and does the trick without paying over the odds prices.   It is compatible with version 4 or 5 of the software  and also comes with software download link which and does the job and is an inexpensive way of getting the job done as has saved me a fortune.     Hope this helps.

Simon

 

Why support buying an outdated and illegal clone of the system rather than supporting the only firm that continues to support Porsche owners?  Get the real thing, it comes with both support and unlimited updates, and can easily be sold on if you move away from Porsche ownership.

[Alexander Tobiasson]

Hi. I have been with My car at Porsche Center in Sweden and they told me to by a new air airbag sensor. Today I installed It and with same result. Fult code 1738 airbag sensor ( driver side) I have tried to reset the code but with negativ result. This is hopeless. I can't get the car through the inspection with this ****ing airbag lamp on.

[JFP in PA]

Hi. I have been with My car at Porsche Center in Sweden and they told me to by a new air airbag sensor. Today I installed It and with same result. Fult code 1738 airbag sensor ( driver side) I have tried to reset the code but with negativ result. This is hopeless. I can't get the car through the inspection with this ****ing airbag lamp on.

 

If it is not the sensor, then as Loren pointed out above, there has to be a fault on the sensor circuit leading back to the control unit.  You need to start checking that circuit for correct voltage and continuity (shorts).  You also need to do this carefully as this testing could easily trigger the air bag.  Disconnect the battery for several min. before disconnecting the sensor and airbag in question, then start testing the harness.

[Alexander Tobiasson]

It is very hard to follow the cable from airbag sensor (drivers) side to Airbag trigger unit. I have located the airbag trigger unit and have Done a visuell inspection. I believe that it is short Cuit in the cable. IT is possible to measure from Airbag sensor to airbag. Pin 78 in airbag trigger is airbag sensor.

[wvicary]

**** so sad ... I have Autel Maxidas Ds708 which is a pretty advanced diagnostic tools. Apparently this is not enough tools?

 

That is a good scan tool and will be able to diagnose your airbag fault.

[Alexander Tobiasson]

 

**** so sad ... I have Autel Maxidas Ds708 which is a pretty advanced diagnostic tools. Apparently this is not enough tools?

 

That is a good scan tool and will be able to diagnose your airbag fault.

 

Yes I know, but i can´t solve the problem...This is a nightmare

[Alexander Tobiasson]

I hope you can follow this link to my photos...

 

 

 

 

Edited November 23, 2014 by Loren
made images viewable here

[JFP in PA]

It is very hard to follow the cable from airbag sensor (drivers) side to Airbag trigger unit. I have located the airbag trigger unit and have Done a visuell inspection. I believe that it is short Cuit in the cable. IT is possible to measure from Airbag sensor to airbag. Pin 78 in airbag trigger is airbag sensor.

 

It is very hard to follow the cable from airbag sensor (drivers) side to Airbag trigger unit. I have located the airbag trigger unit and have Done a visuell inspection. I believe that it is short Cuit in the cable. IT is possible to measure from Airbag sensor to airbag. Pin 78 in airbag trigger is airbag sensor.

 

Again, you need to be careful in doing this type of test as even a static discharge from your body can be enough to trigger one of these system.

 

As for your diagnostic tool, while it appears to be a good one, Porsche uses some unique diagnostic systems in their cars which can easily fool scanners that are not Porsche specific (PST II, PIWIS, Durametric).  This is a common problem that has tripped up more than one DIY repair.

[Alexander Tobiasson]

But what should I do then ??? Porsche Centre also do not know what's wrong and they did not reset, or locate the fault. they referred me to buy a new airbag sensor and I have done. but the problem persists ... crazy disappointed Fault ... No one can help me ... everyone derives me to different sources ... Not should you need replace half the car for an airbag lamp. 

[JFP in PA]

You need to test the circuit for both continuity and correct voltage, but do so with care.  Porsche would do it by connecting a hyper expensive "pin out" box to the harness, you are going have to do it using a multimeter across the harness section.

[Alexander Tobiasson]

This is a open letter to Porsche Leipzig GmHb i email today.

 

Hello, My name is Alexander Tobiasson- I am 38 years old and lives in Sweden. I drive a Porsche Cayenne S V8 4.5 L model year 2004. Reg UJT049. I have owned the car for over 1 year. Unfortunately, the car's air bag system malfunctioned since I bought the car and the owner before've also had problems. The car is my dream and every day I sit in the car I'm proud as hell. I refuse to sell the car and I'll take care of the car in the best possible way. My family says I'm pedantic. I have tried to fix the error for 1 year but no one can help me. The car has had various error codes, it started with 1217. Unfortunately, this is a known bug in the Cayenne 2004 Porsche well know. Porsche remedied the defect free of charge on many cars. It was a two-pin connector that oxidized and it caused a short circuit as a result triggered the airbag lamp. I contacted the Porsche Centre in Kalmar, Sweden and explained the car's problems with error code 1217. They had never heard of the Porsche Cayenne 2004 had had this problem and they refused to help me. They offered to do a troubleshooting for payment. Of course I was sad and disappointed and contacted the largest Porsche forum on the internet. I quickly became aware that I was not alone in this problem. The error was corrected by soldering the cables and put the heat shrink tubing over the connection. After months of searching and consultation, I decided to perform the work yourself when Porsche Centre in Kalmar had no information or wanting to help me. I have read most documents from the Porsche current 2003-08 Restraints Airbag - 9pa_Cayenne. The error disappeared and months of hard work and sleepless nights paid off. The car worked flawlessly for 3 weeks, then came the next error code which is still unresolved. Error code 1738 (AIR BAG SENSOR (DRIVER'S) I have again been in contact with the Porsche Centre Kalmar and I got to buy me a diagnosis. They recommended me to replace the airbag sensor and this I have done but unfortunately with no result. I have also debugged and control measured cables between the sensor and airbag triggering unit and there is nothing to suggest anything wrong. About three weeks I get immobilize the car because out that Swedish law says that all cars with airbags to work. I ask humbly with respect for help from you . My finances do not allow to leave the car in more surveys and it does not seem to be enough expertise here where I live. / All the best Mr Alexander Tobiasson

[Pkscheldt]

This may be of some help:

 

http://www.inkilino.es/Porsche_Cayenne_02-06/AIRBAG.pdf

[mjansari]

i had a similar fault with my airbag and the cable from www.porschecable.com works just fine and does what it says on the tin. 

[JFP in PA]

55 minutes ago, mjansari said:

i had a similar fault with my airbag and the cable from www.porschecable.com works just fine and does what it says on the tin. 

 

Gen 1 cables only use the early software and will be "bricked" if you try and update to the latest version software (6.5.3.2).  Because it can only use the old (several years old) software, it does not have many of the corrections or access to some of the systems on cars built after 2007.  You do get what you pay for..............

[Anderson]

On 5/8/2014 at 4:19 PM, Alexander Tobiasson said:

Hey. I'm new to this forum and owner of a Cayenne S V8 2004., I have had error code 1217 and remedied this by soldering the cables, everything worked fine for 1 month. Now I have received error code 1738 sensor for airbag (driver), and seat occupancy, passanger - too big and Resistance battery open circuit. Are there more connections under the driver's seat that can cause a short circuit? I can not delete the error code ... it comes back right away?

All the best / Alex from Sweden

Hi Alexander, I’m also from Sweden, have you fixed the airbag light problem on you Cayenne? I had a quite similar problem myself last month and today my headache was finally over. Do you still own your car? Let me know if you are interested and I can share my experience and how I found the problem to be fixed.

kind regards 

Anderson 

[davesly]

1738 is definitely the sensor on the Front Left (Driver side in US) under the headlight.  Likewise 1739 is the same sensor on the passenger side.  Once you replace the sensor the error and light will go away (i.e. you don't need to reset it).  I just did this fix last weekend on a 2005 CTT.

Btw, getting the sensor off the mount is really difficult if you live in a salty area.  I basically melted the plastic aound the metal collar, removed the sensor and then used vicegrips and heat on the metal collar to remove it from the post.  To apply heat I used and Induction Heater (Venom).

 

[Hughandjen]

On 12/14/2020 at 10:04 PM, Anderson said:

Hi Alexander, I’m also from Sweden, have you fixed the airbag light problem on you Cayenne? I had a quite similar problem myself last month and today my headache was finally over. Do you still own your car? Let me know if you are interested and I can share my experience and how I found the problem to be fixed.

kind regards 

Anderson 

Hi Anderson

i have the same problem. Fault codes 1738 and 1739. I’ve changed both sensors but still have the fault. Did you manage to fix this type of fault?

 

[Hughandjen]

Hi folks 

I have a 2003 955 4.5s. I have fault codes 1738 and 1739 airbag sensor faults. I have replaced both the front sensors under the headlights to no effect. I have soldered the joint wires under the seats to no effect. My icarsoft por 2 reader give these faults; 

Resistance- battery open circuit 

seat Occupancy passenger too big and

Resistance- driver side airbag too small

i see that many people have had these faults but there doesn’t seem to be an answer?

any help folks!!!