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I have a '94 Fleetwood Limousine. The Passkey Fault light remains on. The problem is not in the steering column. I have checked the system using my VATS Interrogator tool. But here's where it gets interesting. The engine will start and run with the Interrogator selector dial in any of the 15 positions which simulates all 15 resistor block possibilities. The engine will also start and run with the VATS electrical connector unplugged at the base of the steering column. However the Passkey Fault light remains on. Once in a while the engine will crank, then run for a few seconds, then stall. When this happens the ignition must be put in the lock position. The Passkey Fault light will remain on for exactly 3 minutes with the ignition in the lock position. When the Passkey Fault light goes off the engine will start and run again. Does anyone have any experience with this type of problem? I'm thinking it's either in the wiring or the CCM in the trunk. Which is the most likely suspect? I should also note that unplugging the CCM in the trunk causes the Passkey Fault light to go out. So I don't think it's the light circuit being shorted to ground. Any help will be greatly appreciated!! Thank you very much!!
 

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1995 FWB 124,*** miles
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Inserting a proper resistor into the circuit on the car side is very easy and will eliminate the possible broken wire in ignition lock cylinder. I would first do that and see. You can always remove that resistor if nothing changes.
 

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Hi HUF, thank you for the reply and suggestion! I understand about the resistor but I doubt it will change anything. The wiring in the column is good. When I plug in my Interrogator Tool it shows the correct VATS key is in the lock cylinder. I've wiggled and jiggled the key and the wiring looking for intermittents but the Interrogator display stays steady. I've also done the self check on the Interrogator and the tool is working as it should. Two things are puzzling me about this. First, why will the engine start and run with the VATS connector at the base of the steering column completely unplugged or with the Interrogator selector switch in any of the 15 positions? My car uses key number 7. It should only start and run with the Interrogator selector switch on number 7. It would seem that the CCM in the trunk is giving the PCM the ok to crank and enable the fuel system no matter what key is being used or, as in the case of the plug at the base of the steering column being completely unplugged, no key at all. So it would appear that, at some point, the system was bypassed by inserting a resistor in the circuit as you suggested. But I don't see it. Second, if there was a resistor placed in the circuit and a bad connection has developed over time wouldn't the car not start and run at all? I'm assuming, by the wiring diagram in the factory shop manual, if I unplug the CCM in the trunk and check the resistance value at the CCM on the two wires coming from the steering column that value should be the same as the resistor block on the ignition key itself, correct? If it is the same I can rule out the wiring all the way back to the lock cylinder, correct? Then replace the CCM. However if the resistance value at the CCM plug is different than the ignition key, the problem is in the wiring, correct? But if that were the case and the CCM was good, the car wouldn't start at all because the CCM would not give the ok to the PCM to start the engine, correct? Thank you very much for your insight on this and I apologize for so many questions!!
 

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Just wanted to post an update on this. I was able to successfully diagnose and repair this. It was the Central Control Module, as Cadillac called it, in the trunk. For 1993 thru 96 rear wheel drive Fleetwoods this module is referred to as the Body Control Module or BCM in automotive cataloging. It is Cardone part number 73-7386. Contrary to what the cataloging says and what you may be told by others NO programming is required!! It's plug and play!! After much research on this VATS topic a few things became clear. The reason I could start the engine, even though the lock cylinder was unplugged at the base of the steering column, is because when a problem other than the wrong key or no key is being used (such as when the wires break inside of the ignition lock cylinder) the VATS system is disabled by the CCM. That's normal. The fuel enable signal to the PCM is generated by the CCM. If that signal is lost at anytime for 3 seconds the PCM shuts down the fuel injectors and the engine will stall. Even when driving. When this happens a trouble code is stored in the PCM to let you know that has happened. If a problem with the lock cylinder wiring occurs a trouble code will set in the CCM. Each of the 2 wires has a specific code for short to ground, short to positive voltage, or an open condition. I was getting no codes from the CCM. But when the engine would start, run a few seconds then stall I got the fuel enable signal lost code from the PCM. A very good mechanic once told me that the computer will never tell on itself. It will tell on everybody else (sensors, wiring, etc.) but never on itself. So with the symptoms I had and no codes from the CCM I was 95% sure the CCM was bad. I was right! Hopefully my experience will help someone else who is struggling with a similar VATS problem!!
 
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