Cadillac Seville / Cadillac Eldorado Forum Discussion, 1997 STS VATS problem in Past Cadillac Vehicle Discussion; i have a 1997 Seville STS an it shut down going down the road when i was passing someone an ...
i have a 1997 Seville STS an it shut down going down the road when i was passing someone an i got the dreaded "theft system problem, Car may not restart" but when i checked my OBD the theft system didnt show up.. the fuel pump wouldnt come on but when i removed the pump an hooked it strait to a battery it came right on.. please help ive tried almost everything
When you insert the key in the ignition cylinder there are 2 contacts inside touching the little pallet at the base of the key blade. That pallet is a resistor and this resistor will have one of the 15 possible values:
Basically the key will become part of an electrical circuit so the IPC can read the value of the resistor in the key and validate if is correct (will compare the value with the one stored in its memory as expected value). If is in the acceptable range will sent "start enable" the encrypted message.
When the PCM receives the message will enable the started and fuel pump relay AND the injectors. Just by jumping the fuel pump relay will still not make the engine start as the injectors are disabled (off).
This is the diagram of the circuit:
If the started enable password is not received the PCM will not start the engine, also the IPC will display "Starting disabled remove key", then every minute will refresh the message with "WAIT 3 MINUTES", "WAIT 2 MINUTES", "WAIT 1 MINUTE", "START CAR". It will also post a theftlock code that will turn to history in the moment the correct VAT is read.
You have an issue somewhere on circuit 173 or 174. Most common points of failure (bad contact) are the contacts inside the ignition lock cylinder, the key terminals (mat be dirty or worn out), the contacts inside the C202 connector (pin E12 or E13) or the very thin wires between ignition cylinder and the C202 connector (sometimes they break).
You can temporarily bypass the system by installing an appropriate size resistor as shown here:
To find out the correct resistor value measure the key resistor using an ohmmeter with the leads touching the contacts on the ket on each side of the key blade.
With the bypass you can spend the time and find exactly where the issue is, wires, key or Ignition cylinder.
No, VAT will not cause the car to stall once started (is a safety issue), but will prevent it from starting.
So unless you get the messages I mentioned ("THEFTLOCK ENABLED, REMOVE KEY", "WAIT...") is not a VAT issue.
Now as for wire cutting, he may cut the wires then find out the issue was in the big connector underneath the steering column, now what...
WHY cutting wires when you can unplug the connector (like I described) have your temporary fix done, nothing damaged in the process, then take the time to see exactly what went wrong.
There is one thing I REALY HATE, the shops doing rust proofing (spray some oil in the doorsills). They drill holes in the doorsills right next to the existing factory holes. All you need is pry the plastic covers and there are 4-5 holes in there (1 inch away from the one they drill). This qualifies the same as cutting the wire 1 inch away from the connector when you can just unplug the connector. Plus I explained many times the bypass should be done at the IPC connector not somewhere half way on the wiring, what if the issue is upstream on the wire?
Like I said you NEVER EVER need to cut a wire, there is always a connector on the circuit.
well i did some research an i guess i may have misunderstood... it seems the crankshaft position sensor is the one that can cause a stall out during heavy acceleration an keep the fuel pump from coming on as a safety measure but i cant find anywhere that it tripped the vats system.. in at a complete loss, ive never had a problem such as this
Really not positive but I believe VATS will not disable a vehicle that's running. I think I would test the fuel system for another problem,maybe a relay? I have had vehicles with VATS if they were running and they had a security issue they would stay running but would not restart. I think the security light was a result of the stall.
N Caddy nice explanation of VATS and how to "test" with resistors