I'm writing this for my elderly father who has no idea what more to do
about his car. Any replies or suggestions would be greatly
appreciated. His car is a 1997 Chevy Lumina and sometimes it won't
start. If he waits five minutes or so and tries again, it starts just
fine. It happens every other day or so. He's replaced the battery,
the alternator, and the starter each time thinking that it would solve
the problem, but it hasn't. He thought maybe it was the chip on the
key, but it does the same thing with two different keys, so it's not
that. It is driving him nuts and he, in turn, is driving me nuts, so I
hope someone has a suggestion because I certainly could use one.
Thanks for the reply, I appreciate it. No, it doesn't turn over, it
just does nothing - no clicking like the battery is dead, doesn't try
to start, it just does nothing. But if he waits a few minutes and
tries again it works just fine. I don't know about the security light,
but the rest of the lights go on when the key is turned in the
My Grandparents have the same car, and had the same problem. It turned out
to be an aftermarket remote starter they had installed years ago when they
bought the car. The remote starter was keeping the car from starting. We
took the remote starter out, and the car has worked fine ever since. If I
were you, I would still check out the VATS system by looking for the
Security light, like Shep said, but if that doesn't turn out to be the
problem, check to see if the car has a Remote Starter on it. I have had at
least 2 cars where the owners have told me the cars don't have remote start,
but I found the remote start box under the dash.
I've been doing some reading about that VATS system, and you guys are
right, that sounds like it's exactly what the problem is. Thank you
guys very much for leading me in the right direction. Now I know what
to do about it, I just have to talk my father into letting my friend
disable the thing instead of having it replaced, which I think would be
a huge waste of money.
80 Knight wrote:
If the VATS module is bad you will have to replace it. Just
unplugging it will NOT work! The PCM (engine/transmission computer)
expects a digital pulse code from the VATS module to enable the fuel
injection. No pulse, no fuel injection (this is done so thiefs can't
just "hot wire" around the VATS system)..
If, however, the problem is the ignition cylinder or the wiring from
there to the VATS module, you can disconnect the cable from the
cylinder and splice in a resistor of the same value as the resistor
key pellet. The VATS module will then think the key is present with
the proper resistor and work correctly.
Uh-oh, looks like I'll have to figure that out, then. Thanks, William.
I thought from what I'd read that I could have a friend splice in the
resistor for me and it would cure the problem. I will have the person
check the module first since I really have no clue about this stuff and
how to determine if it's a bad module or not. Hopefully he will know.
William H. Bowen wrote:
VATS stands for "Vehicle Anti Theft System". This was the original
name for the system that GM first put on the mid-80s Corvettes and has
rolled out to most of the remainder of its line. The current name for
that system is called "PASS" (Personal Auto Security System).
The idea is that a thief would not be able to start your car unless
they have an ignition key that matches both the physical key cut (so
the ignition lock will physically operate) but also that the key has
to match electrically as well. The VATS/PASS module controls a relay
in line with the starter solenoid feed - when that relay is not
enabled by the module, the starter will not turn. In addition, the
VATS/PASS module sends a digital data stream to the ECM (engine
computer): without that data stream the ECM will not enable the fuel
injection for the engine. No fuel and no crank = no start.
Since the VATS keys have an embedded resistor slug that can have any
one of 15 different resistor values, you have increased by a factor of
15 the possible combinations. Also, the VATS/PASS system will disable
starting even with the correct key for 3 minutes if an attempt to
start is made with an incorrect key. This will slow down an attempted
theft (and the longer the thief is exposed the less likely he/she is
to actually steal your car).
The newest versions of the PassKey system don't use a resistor
pellet in the key: it instead uses a transponder that communicates
with some embedded electronics within the key - similar to the RFID
systems being used to tag store merchandise.
If the ignition cylinder has been replaced and the VATS/PASSKEY
system is still acting up, check the wiring from the base of the
steering column to the VATS/PASSKEY module. Any intermittent
connections will cause the problem you describe. It is also possible
that the VATS/PASSKEY module itself is bad. If that is the case, you
will need to replace it. You can "hotwire" around a bad igintion
cylinder but you cannot easily bypass the VATS/PASSKEY module itself
(since the ECM requires the pulse train from the module for the ECM to
enable fuel injection).
Thank you so very much for your information. Hopefully I can get this
taken care of. I already have quite a bit in the car, just had to
replace the catalytic converter fo pass emissions and I really do like
the car. Bless you!
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