docmirror

I've use the John Speake diagnostic tool to locate the problem with my 'airbag malfunction' indicator. I started out with several codes;

High resistance crash sensor II,

high resistance crash sensor I,

open circuit ignition pill I,

open circuit ignition pill III.

From this point, I used the reset function of the diag tool(we gota come up with a shorthand name for this thing) to clear the codes, and then run the test again. Second time through, all codes were cleared except 3129 which is high resistance crash sensor I. Now, through a series of complex calculus, I've decoded that the crash sensor I on the John Speake Diagnostic tool decodes to the 'crash sensor left' in the WSM.

The tool works great, and I used it to reset my codes, then diagnose the problem quickly. I will do the LH/EZK test tomorrow. High marks the John


Fine, from the wiring diagram grid K-71 of page 97-357 I've found the circuit. And from page 68-24 troubleshooting I've found a description of the sensor. But -- NO PHOTO of the darn thing. So, off to the tech pubs, disk 2, airbag system page 30-43, lots of blather, photos of the locations of everything except the ^*#$@%* crash sensor!

I think it looks like a small voltage regulator with two mounting flanges, and the discussion says driver's footwell, upper section on wheel well. So I can't see the darn thing!

Can someone give me instructions on how to find the crash sensor please? I'm thinking along the lines of "lay in driver's footwell on right side, angle head up....blah, blah, blah." I need to measure the resistance of the trigger wires and trace them back to the control unit in the center console(found that). I could try tracing the wires from the control unit, but the wiring is routed pretty wild.

Thanks for any assist, once I find it, I'll take a photo and describe my testing and fix.

PorKen

I like the name "Spanner", which I've overheard the tool be called.

ROG100

Doc,
Glad to see the "Spanner" worked on your car.
I am interested to see if it works on mine after hearing it did not on Ernies yesterday.
Roger

docmirror

Bump;

"Spanner" it is then, unless someone has other ideas. Now where's that pesky sensor?

For those wanting to disable the system without getting the indicator lamps on, I think I've figured the correct procedure for that, but I'm not willing to share it on a public forum. Inquiring minds can PM, and I'll describe the circuit. You may draw your own conclusions on how to proceed. I am NOT advocating this, and I may even require a signed waivier before discussing the job. REF: Recent post on "has anyone ever been killed in a 928".

JS: Are you interested in field feedback on the Spanner interface?

docmirror

Okay, I'm bumping my own post, but we've got it fixed and wanted to share the results.

DISCONNECT THE BATTERY! DISCONNECT THE BATTERY! DISCONNECT THE BATTERY!

Crash sensor left: Lay on your back in the driver's footwell, and slide your head to the dead pedal side. Using a 10mm open end wrench, remove the nuts and bolts holding the RDK controller and the other controller next to it. Pry off the connectors for those controllers and set them aside. Looking straight up, in the well above the controllers is the sensor, looking like a small voltage reg, with a black case and plated ears. The bolts used are special and require a one time removal tool. I didn't remove mine but was able to test it in situ.

Testing: With the drivers door open, remove the rubber donut that ducts air to the drivers door vents. Slide the courugated duct in the dash up out of the way, and look inside for a rubberized connector mounted in a brace on a frame tube. You will need some very long needle nose pliers, or someone with small hands(thank you Zane!) to reach in and unhook the connector from the frame mount. It will then hang down and can be separated. Using a ohmmeter, connect the + lead to the female pole on the sensor lead, and measure resistance to the other two leads. You should read 10 ohms on each lead. Now measure the resistance between the two male connectors, it should be < 1 ohm.

My car showed high resistance, left crash sensor. The sensor ohmed out correctly so I snapped it in and out a few times, and returned it to it's clip. After putting things back together, I tested the airbag with the Spanner again and reset the codes. Ran the test again and NO CODES!!! Yipeee! The sensor can be replaced but you will need a pair of pliers(or the special tool) to remove it from the chassis.

Thanks to Roger again, and Zane for the use of the Spanner, and the beer. I can now get my car inspected and it should pass.

Doc

John Speake

Hi Docmirror,
I only just read this thread, so hadn't realised I was mentioned in it !

Yes, "Spanner" is the namethat I will use. I will update the website.

I very much appreciate any feedback on the Spanner. There are a couple of cars that haven't wanted to diagnose. There is usually a good reason, sometimes rather obscure, as Schocki found out.

So far I'm very pleased with the good reception the tester has had.

Now you guys, stop sharing them ariound, and buy one for yourselves !

Regards