Hi,

I've had the Airbag Code 49 for a while now. At first I thought it was related to a harness connector that needed cleaning, so I did just that. Code remained. Today I had the Recaro Seat out again, and did a thorough measurement of the connectors and the seat position sensor. Following the SRS code guide, I got these results:

- Wiring from sensor to harness is good.
- No short circuits to ground or battery
- Disconnecting the sensor, there is infinite resistance over the sensor leads.

Q: Should the sensor give any resistance when measured?

In case the answer is yes, I would be in the market for a new seat position sensor, which has the marking HJE-9684-AA. I haven't found this thing in JPEC, googling also turns up nothing. Any idea where to find this part?

 

New, it appears to be part of the entire track assembly.

 

Does that also apply to the Recaro seats?

 

not sure, if you go to Guadin's website, you can look under the XKR, see if there is mention of the recaro option. I'll hazard a guess that it isn't any different.

 

Update: I still haven't found out what causes my 4-9 code. I have tried reseating all connectors, sprayed contact spray etc.

However, last night I stumbled upon some documents for a Ford model, which appear to be 100% valid for the SRS system in our cars. With the help of the pinpoint guide, I should be able to sort out the issue.

Index of /service_man/Body/Body/501-20B_Supplemental_Restraint_System/DIAGNOSIS_AND_TESTING

Will have to wait until next week though, since I'm away from home for a week due to business matters.

 

Please let us know how you get on - if those documents are relevant I'd like to add them to the How-To section.

 

They are very much relevant - it is in fact the same SRS module, the same harness with the same pinouts. I'll let you know.

 

Went through the relevant parts in the problem-solving document, but since I have no WDS, nor a "known good seat position tracking sensor", I cannot follow through completely.

All measurements looked pretty ok. One measurement that seemed a bit off, is that when measuring the sensor harness resistance to ground, I got 160 ohms (ground in this case being a metal part of the seat), where document says "should be less than 5 ohms". Could my problem be due to some bad grounding of the seat? Any ideas on how to check/improve on that?

I heard grounding in our cars is a convoluted topic.

 

So today I had what feels like my fiftybillionth go at this issue again, taking apart everything related to the seat position tracking sensor.

All measurements up to the sensor connector turned out well, so the final step was to take the actual sensor off and apart. The sensor housing is attached with rivets, so some drilling was required to get it off.

Turns out that all the plastic housing contains is a magnet on one side, and a little circuit board on the other. There are 2 screws, a plastic strip and a rubber piece holding the circuit board in place, once those are gone, the board can easily slide out. Picture shows that it is a simple circuit with one resistor, one capacitor and a hall effect sensor.

Now I simply went on to measure the resistance between the board cable solder points and the connector. Lo and behold, there was no connection at all! I then pulled a bit on the cables, and revealed a clean break inside BOTH cables.

All I had to do was to cut the cables at a clean point, and solder them clean to the circuit board, then put everything back together.

Finally the nasty 4-9 airbag flash code is GONE!

The reason for the break must be the the plastic strip that keeps the circuit board in place. It simply bends the cable way too much. I didn't put the screws in too tight when putting it back together, leaving room for some cable flex.

 

Fantastic result! These various airbag sensor issues can easily drive us nuts. An entire book could be written about them, then dedicated to Graham....

Any new progress on your Code 17 issue, Graham?

 

I just read this thread and see the last comment from Jon 89 re the code 17 fault to graham...iv'e just come through a code 17 fault that took me 4 months to fix, if you
Would like Graham to give me a PM I will gladly share the details.

 

I posted this a while ago, but I would call these the best documents for pinpointing errors in our SRS system:

Index of /service_man/Body/Body/501-20B_Supplemental_Restraint_System/DIAGNOSIS_AND_TESTING

It is not dedicated to Graham, but works well anyway

 

Trevor,

I still have the Code 17 and annual MoT is due in June. This is now a 'fail' under the new test regulations so I have to resolve it.

The final thing to left to check is the Airbag Control Module and its harness connections.

I'd be very interested to hear your experiences with this code. I've sent you a PM.

Graham

 

we really appreciate the follow up azeteg! good job, you deserve a cold beverage of our choice as a reward.

 

I figure, the more people that follow up on their problems and solutions, the more valuable this forum gets. Nothing worse than reading an n-pages thread about a problem without a solution.

 

First, azeteg, you rock!

In the fall of 2013 I started to get 4-9 errors. They didn't happen right away, usually when I shifted positions in the seat. Now, I'm 6'3" 200lbs, so I push the seat bottom down pretty far, so I figured a bad sensor. I read through the posts (this one included) and saw that it required taking the seat out, etc. I didn't feel like it until this weekend. I took the seat out, reset connections, jiggled things (and took the time to do a thorough carpet cleaning and leather treatment!) and after starting the car back up, I found that I got the error every time I started the car!!! So, instead of fixing it, I broke it more! Go figure. But it really did make me feel it was a broken wire.

So, reading this thread over again, I just had a gut feeling the wire were broken on the seat position sensor. I took the seat out again, drilled out the rivets holding the sensor in, put it up on the table, took it apart and lo and behold, broken wire at where they enter the sensor, same thing as azeteg found! 15 minutes of soldering and it appears to be good as new.

So, I have to make a comment here. I was an avionics technician in the US Air Force and we were taught some things about wire bend radius and strain relief. Believe me, this is not the first time I've seen wire pulled to within a mm of it's life in this car! I understand there is a need to save a few pennies on copper, but really folks! Jaguar, give it another inch please!

So, we will see how my repair holds up. Hopefully I got this one fixed. Now I just need to figure out why my ABS/Traction control keeps going out! I know! Wheel sensors, wire harness, ABS Solder joint! I've already fixed the solder joint once already, so I'm really hoping its just dirty sensors this time!!!!

My hats off to everyone! Please keep posting!

 

I agree, this is definitely a design flaw. I'm happy to hear that my solution worked for you too

 

Great post - hoping it's something similar for an X100? (UK 2002 XKR 4.0)

I found the diagram below:


Looking under my seat though I can't see where this is (ringed on the lower right hand side) - do I need to take something else apart to get to it?





I also 'played' with the item ringed at the top centre, wondering what this was... inside it says SR2220; I know SRS relates to airbags but that may be unrelated - randomly as well there's the number 0049 and this is the 49 airbag error code - pure coincidence though I'm guessing?!

Thanks all
Ross

 

Found it! For some reason thought there were two sensors; so had ignored the bottom arrow for "3" in the diagram. That's where the sensor was - bottom right corner (see photo below). I could see the wires had frayed; so cut them and added a re-soldered - all works now!!

Much easier to take the car seat out else very difficult to get to.