Front Impact Sensor Wiring
 

Okay guys, technical question.



Issue:



Instrument cluster Airbag Light has been illuminated at all times for the past year or longer. Taken to the dealer yesterday and the problem was identified pretty quickly. A rodent has chewed through the two wires that go the the Front Impact Sensor. Apparently these wires cannot be soldered or repaired. The dealer states that these wires have a specific resistance and this is why but I I'm not entirely convinced this is true and suspect it is more a legal and safety issue. ( http://www.hemanual.org/general_safe...tion-1771.html )



Solution:



Their suggested repair - replace the engine wiring harness for $2800. Well, the car is only worth $4500 so I am not willing to do this. The part online is about $1500 so I assume labor is around $1300. A used harness is about $200 but labor would likely be close or the same somewhere else.



Question:



Can I just repair the wires to the Front Impact sensor?

or

Replace the two wires from the sensor to the wiring harness?



Thanks,

Richard

I'd call BS, disconnect the battery, be damn sure not to be wearing plastic clothes and maybe wear an ESD strap and ground my body to the car . . . and just patch the wires. They're wires, and a bad connection will have more contact resistance than using a couple inches of the wrong wire. Fix them and go to a different dealership if possible, to reset the light if it doesn't go out on its own.



...I could be wrong though. I've never heard of such a thing (in a car).

Every shop is going to be VERY touchy about working on the airbag system, because like a/c, they need to be certified and compliant with stringent procedures. Airbags and their wiring systems are enshrined by law, probably for good reason too.



There isn't a whole lot of information out there about tolerances and allowable resistances etc, because of reasons mentioned above. Safest bet would be to replace the harness yourself with something from a wreckers yard.

Yes, you can repair the wires. We do it all the time at Nissan. We actually had a TSB on older Titans to lengthen a passengers side seat sensor harness by cutting it and splicing in an extension. We use these style of connectors (crimp with solder built in):



http://www.connectorsupply.com/catal...2_18_gauge.JPG



You cut and strip the wires, crimp this on then heat with a heat gun to shrink the outer insulation and melt the solder pellet in the middle. We don't use any kind of ground strap. Just disconnect the battery and wait 10 minutes for all of the modules to power down.

Thanks. That makes me feel much better. Hopefully I can get this thing working again today.