A couple days ago, my air bag lamp flashed as I approached a stop. I had
to fast blinks followed by one slow, which I translated as a code 21. My
internet search found "safing sensor improperly mounted." Any input on
whether my translation is correct as well as information on how this code
is determined, and where the safing sensor is located would be
You have three sensors. Two under the corners of the front bumper,
and one either on top of the radiator or on the firewall. They will have
4 to 6 wires and have a blue arrow facing forward. This code could be
caused by a bad ground to chassis of any of the sensors.
Remove the battery connection for a hour or so. Then remove the sensors
one by one and clean up the mount grounds with sand paper or wire brush.
Remove the connector and re plug it while your at it.
Then restore the battery connection and see what happens.
The air bag controller and power supply are behind the glove box
in blue modules.
Thanks, Bob. I know where this safing sensor is. I always thought that
was my main sensor. I'll have to check it. I think I probably took it
loose to install my radiator in February. If this bolts onto the radiator
support like I suspect, the bolt holes may be stripped.
The center module has both the crash sensor and the safing sensor in
it as i recall. If the air bag computer does not see a certain resistance
on the safing lines, it sets the fault code. I think the center sensor was
6 wires and the sides four or such. I would have to pull out the manuals to
Air bag information is hard to find. It took me a long time to get my 90's
fixed. Turned out to be the air bag computer in that case.
I pulled the sensor off the radiator core support to have a check. All
bolts appeared tight and no signs of excessive rust. There is a four hole
connector for the sensor, three of them with wires. Reattached sensor and
checked voltage drop with car running and headlamps on. About 20mV. The
lamp hasn't come on for a few days now. What do you think the odds are
there's an internal problem in the sensor that'll trip the light again?
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