1994 Vats
02-15-2012, 10:37 PM
#21
Instructor
Thread Starter
Correct
but there are three parts to VATS.
First it has to read the key correctly ,if it does that ,then it has to send the fuel enable signal
to the ECM to fire the injectors and activate the starter relay.
Any of these three parts can fail independently of each other, identifying which is at fault
when you have a no start condition is the problem
but there are three parts to VATS.
First it has to read the key correctly ,if it does that ,then it has to send the fuel enable signal
to the ECM to fire the injectors and activate the starter relay.
Any of these three parts can fail independently of each other, identifying which is at fault
when you have a no start condition is the problem
So you are both saying that the Baker unit will take care of all three issues...
02-16-2012, 12:16 AM
#22
Le Mans Master
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The Baker unit supplies the required signal ( that is usually supplied by the VATS) direct to the ECM
completely bypassing the the VATS unit altogether
( the resistors only fool the VATS unit into thinking correct key in the Ign )
You also have to bypass the starter relay that is also controlled by VATS
VATS gone completely;
unfortunately you leave yourself open to theft ;screwdriver in the Ign and it's lost
What some do is wire the Baker unit on a hidden switch so when it is off car reacts the same way as if it had VATS; no fuel signal
02-16-2012, 12:25 AM
#23
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TSB # 88-292. July 1988
http://www.corvetteforum.net/c4/rayq...sbs/88-292.htm
Notice GM fixed the key reading problem in 1988 with a new lock cyl so that TSB
doesn't apply to the OP's 94 car
You might want to add this from Ray Q to your bookmarks
TSB's for early C4's
http://www.quayle-co.com/tsbs/
http://www.corvetteforum.net/c4/rayq...sbs/88-292.htm
Notice GM fixed the key reading problem in 1988 with a new lock cyl so that TSB
doesn't apply to the OP's 94 car
You might want to add this from Ray Q to your bookmarks
TSB's for early C4's
http://www.quayle-co.com/tsbs/
Last edited by rodj; 02-16-2012 at 12:34 AM.
02-16-2012, 11:55 AM
#24
Rodj, as always your info is excellent, cant find the sheet I was reffering to, but I'm adding yours to my favorites, its excellent reading, many thanks, respectfully, bob
Last edited by oldalaskaman; 02-16-2012 at 11:58 AM.
02-16-2012, 12:11 PM
#25
Instructor
Thread Starter
After reading all the post on this thread it seams that
the safe road for me to take would be to go with the
Baker unit. I can see that all of you are very passionate
about our Corvettes... Thanks Again to all...
the safe road for me to take would be to go with the
Baker unit. I can see that all of you are very passionate
about our Corvettes... Thanks Again to all...
02-16-2012, 02:11 PM
#27
Melting Slicks
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The FEDS (fuel enable disable system) allows the
pulsing of the fuel injectors. On a 94, the CCM communicates
with the PCM via the serial data bus using a password exchange
to enable FEDS.
There is no separate FEDS input line to the computer like on the older computers. (This is the line the Baker kit uses).
The only way to defeat the FEDS is to have the computer
reprogrammed so the FEDS is ignored.
When you insert the ignition key and turn the
ignition On, if the key pellet resistance value
does not match the resistance value the CCM
was programmed for, the Security Light on the
left side of the dash cluster will stay on Solid
which sounds like your problem. It will also
set a Diagnostic Trouble Code.
The resistor kit Ecklers sells will solve
that problem. Or you can purchase resistors
at Radio Shack for a couple of dollars.
The key pellet could also be worn out or dirty.
Try a different key or clean the key pellet.
Most likely there is an intermittent break in the
wires that transfers the key pellet resistance
to the CCM. The fix is to replace the Ignition Key
cylinder. That also requires new keys to be cut
with the proper key pellet resistance values.
Last edited by Hooked on Vettes; 02-16-2012 at 03:38 PM.
02-16-2012, 06:18 PM
#28
Instructor
Thread Starter
The Baker kit doesn't work on a 94 Corvette.The FEDS (fuel enable disable system) allows the
pulsing of the fuel injectors. On a 94, the CCM communicates
with the PCM via the serial data bus using a password exchange
to enable FEDS.
There is no separate FEDS input line to the computer like on the older computers. (This is the line the Baker kit uses).
The only way to defeat the FEDS is to have the computer
reprogrammed so the FEDS is ignored.
When you insert the ignition key and turn the
ignition On, if the key pellet resistance value
does not match the resistance value the CCM
was programmed for, the Security Light on the
left side of the dash cluster will stay on Solid
which sounds like your problem. It will also
set a Diagnostic Trouble Code.
The resistor kit Ecklers sells will solve
that problem. Or you can purchase resistors
at Radio Shack for a couple of dollars.
The key pellet could also be worn out or dirty.
Try a different key or clean the key pellet.
Most likely there is an intermittent break in the
wires that transfers the key pellet resistance
to the CCM. The fix is to replace the Ignition Key
cylinder. That also requires new keys to be cut
with the proper key pellet resistance values.
pulsing of the fuel injectors. On a 94, the CCM communicates
with the PCM via the serial data bus using a password exchange
to enable FEDS.
There is no separate FEDS input line to the computer like on the older computers. (This is the line the Baker kit uses).
The only way to defeat the FEDS is to have the computer
reprogrammed so the FEDS is ignored.
When you insert the ignition key and turn the
ignition On, if the key pellet resistance value
does not match the resistance value the CCM
was programmed for, the Security Light on the
left side of the dash cluster will stay on Solid
which sounds like your problem. It will also
set a Diagnostic Trouble Code.
The resistor kit Ecklers sells will solve
that problem. Or you can purchase resistors
at Radio Shack for a couple of dollars.
The key pellet could also be worn out or dirty.
Try a different key or clean the key pellet.
Most likely there is an intermittent break in the
wires that transfers the key pellet resistance
to the CCM. The fix is to replace the Ignition Key
cylinder. That also requires new keys to be cut
with the proper key pellet resistance values.
02-16-2012, 06:44 PM
#29
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or get a spare key cut
Much confusion arises because the VATS operation and how it interfaces with the ECM /PCM
as changed over the years so what works for earlier years won't work for later which need a different fix
:
02-16-2012, 09:26 PM
#31
Burning Brakes
I did the Radio Shack Resistor fix along with adding an additional "Painless Starter Relay" under the hood and it has eliminated all of my VATS problems - and I was having issues all of the time. My car had gotten to the point that I could not depend on her to start.
I added an additional "Painless Starter Relay" from Summit Racing under the hood. I was told that there was a possibility that the starter wires had gotten old and were loosing the capabilty to carry the amperage. A problem that plagues older GM vehicles. It solved my problems that had plagued me for a few years.
I added an additional "Painless Starter Relay" from Summit Racing under the hood. I was told that there was a possibility that the starter wires had gotten old and were loosing the capabilty to carry the amperage. A problem that plagues older GM vehicles. It solved my problems that had plagued me for a few years.
Last edited by trulytex; 02-16-2012 at 09:56 PM.
02-17-2012, 12:11 PM
#33
Instructor
Thread Starter
Is it possible that maybe this Vats Failure was just a freak...
It only happened one time. Has anyone had this happen on a '94, '95 or '96 car?
It only happened one time. Has anyone had this happen on a '94, '95 or '96 car?
