wrangler, airbag , check engine light and no bus

Every once and a while the airbag light will come on and than the check
engine light too. the odometer goes blank and reads no bus. I have changed
the fuses for the airbags but problem is still happening. if anyone can
help i appreaciat it.

 

Your pci bus is either failing (the bus originates from the BCM), or one
of the modules that usues the bus is dragging that bus down (shorting it
out). (PCI bus is the single-wire bus over which all the various
modules of the vehicle communicate - if it fails you see exactly what
you are seeing.)

You have a Wrangler (though you don't say what year), but I know from
reading the LH car forums (LH cars have similar bus and module design),
when this problem occurs (with the "no bus" message in the odometer
window), the problem generally ends up being a bad TCM. You can either
pay to have it troubleshot (no guarantee that they'll nail it due to it
being intermittent - but you'll still pay a bunch of money), or take a
small gamble and get a TCM (the right one to work with your vehicle)
from a junk yard for under $50 and have a very good chance of that
fixing it (if it doesn't, you're only out $50). Plus *IF* the dealer by
some miracle pinpoints it, they will charge you *several* *hundred*
dollars for a replacement TCM (*plus* the diagnostic time)

I got a $6000 Concorde for $1000 last year because it had this exact
problem and the used car lot spent (wasted) all kinds of money at the
dealer testing and replacing this and that with no success. The problem
went solid for a couple of days, allowing me to pinpoint it to the TCM
(plus, as I said, the LH car forums kind of led me in that direction).
Got a TCM from a junk yard - no problems since. Four hours plus $50 for
the part invested.

To locate a TCM for your vehicle, use the drill down at
www.car-part.com. You can narrow the search to state or region to keep
shipping time to a minimum, but even if they have to ship from 7 states
away, so what. You'll probably find several listed in your state or an
adjacent state - like I said - for under $50 (after you drill down with
vehicle and part, start by clicking on the page with the asterisk, and
work your way backwards to find the best price).

Bill Putney
(To reply by e-mail, replace the last letter of the alphabet in my
address with the letter 'x')

 

Some Wranglers had cluster connector issues that cause problems like
you're having. Look for TSBs for your vehicle.