Technical Airbag light - wires for front crash sensor

[gording01]

Hi,
So it's my first post here, but been a regular viewer on the forum for the last few years - great stuff!!

But now I need specific help: My girlfriend has a Grande Punto 1,3JTD from 2007 and the airbag light has been on for a while now. Initially I was able to reset it with a simple/low cost OBD2 diagnostics tool (could not get an error code, but the erase was successful), but after a few weeks the light came back on again.
Then I had the local dealer hook up his tester and it came out with the error code "8117 Front crash sensor - incorrect signal". So I removed the sensor and had a multimeter on it - no short circuit, so I guess that means it's ok. (??)
Next up I looked at the wires between the front crash sensor and the airbag control unit (the one under the center tunnel in the cab) and here's where I'm really on thin ice: With the sensor and control unit disconnected I measured a short circuit to the chassis/ground on one of the two leads in the wire at the sensor --> that isn't right, is it??
I suspect the wire has been chewed over at some point and want to cut it out and replace it, but the control unit has 2x connectors with 24 leads each and I've got no idea which should connect to the front crash sensor

Can anyony please help me with a wire diagram or something like it of this area? (english is prefered - I found something in italian, but wasn't the right car model and let's just say that Google Translate didn't really help much either...) Also any comments that could help me get it fix is much appreciated!

Hope to hear from some of you geniuses out there soon - much thanks in advance!!

- Peter

 

[Andy Monty]

not sure on the wiring schematics for the air bag look in the forums download section in the grande punto section you can get the full workshop elearn download which does have wiring diagrams IIRC



BUT PUT THE MULTI METER DOWN A PULSE DOWN THE WRONG WIRE COULD BE ENOUGH TO DEPLOY THE AIR-BAGS even soldering a wire can lead to a discharge be it static or the iron itself leaking current

 

[cromalee]

disconnect the battery and wait 20 mins before messing with the abs ninjas,,,:devil:


Im thinking that one of those wires should be going to ground. If its anything like the passenger airbag switch problem in the punto 2/2b its probably a bad earth thats causing the error.

I'd check for a bullitin from fiat about this before I would attempt a fix.