Fleetwood PassKey II Issues

Wiring, DIY, lighting, etc.
Post Reply
Adam
Posts: 2245
Joined: Wed Oct 23, 2013 9:50 pm

Fleetwood PassKey II Issues

Post by Adam »

The PassKey Fault light has been on since I got the car. Recently I have been getting CELs resulting from not being able to verify the key. At some point I'll end up not being able to start the car, which would be bad. So, time to fix the Fleetwood!

Fun reading:
http://www.impalassforum.com/vBulletin/ ... -vats.html

I measured my key and came up with 2350 Ohm. That matches the #8 key at 2370 Ohm. I tried to find a resistor in the range for the #8 key: 2275 - 2485, but couldn't. Instead, I found two 4700 Ohm resistors. Soldering them in parallel gives me 2350 Ohm. Perfect.

I tried to measure the resistance of the key at the harness and couldn't get any reading at all, no matter how I wiggled things. How convenient. I was able to jam my resistor pack into the harness as-is without needed to cut stuff.
IMG_20170628_174154.jpg
Started it up and no more PassKey Fault light or CEL.
IMG_20170628_174139.jpg
Fixed forever.
kevm14
Posts: 15245
Joined: Wed Oct 23, 2013 10:28 pm

Re: Fleetwood PassKey II Issues

Post by kevm14 »

That wasn't very hard.
Adam
Posts: 2245
Joined: Wed Oct 23, 2013 9:50 pm

Re: Fleetwood PassKey II Issues

Post by Adam »

Good thing I waited so long...
bill25
Posts: 2583
Joined: Thu Oct 31, 2013 2:20 pm

Re: Fleetwood PassKey II Issues

Post by bill25 »

This is interesting. So if you put exactly what the resistance that was being looked for directly in, and everything worked, that means that there was effectively nothing being provided from the key and it still started the car??? Seems like more than just lights being on should have been happening, like the key not starting the car... It sounds like with the lights being on a module or something failed and the car was bypassing the reading and just allowing the car to be started. Is that accurate?
kevm14
Posts: 15245
Joined: Wed Oct 23, 2013 10:28 pm

Re: Fleetwood PassKey II Issues

Post by kevm14 »

The key is still required to turn the ignition switch to run and crank. But if the VATS module doesn't see the right resistance (which is supposed to be measured from the key when you insert it) it wont enable the starter or injectors. Putting in that resistor effectively turned his passkey into a normal key.

I don't suppose those resistors could rise or drop out of range in temp swings enough to cause an issue, could they? Looking at maybe a 150F total temp swing possible over the range.
bill25
Posts: 2583
Joined: Thu Oct 31, 2013 2:20 pm

Re: Fleetwood PassKey II Issues

Post by bill25 »

The key is still required to turn the ignition switch to run and crank.
Yeah, I know you still need the key for that... I meant electrically.
But if the VATS module doesn't see the right resistance (which is supposed to be measured from the key when you insert it) it wont enable the starter or injectors.
He said it was still starting the car with the wrong reading which was what I was curious about.
Putting in that resistor effectively turned his passkey into a normal key.
This doesn't make sense because he said he measured the resistance of the key and it was not zero, but close to what it was supposed to be. The key would still be part of the circuit if the circuit wasn't broken. Doesn't the key basically complete a circuit that has to have some known voltage drop to start the car? So if the key was being registered as resistance, adding the correct resistance being looked for, plus the key should disable the ignition since the additive would be more, and should have registered as out of range. It seems like the circuit to test was being bypassed, and now with the correct resistance added, it is being accepted. Seems like an open circuit allowed the car to run but had lights on, and Adam "closed" the circuit with the exact resistance, but since something broke in the real circuit the exact resistance is seen as correct since the other circuit is still broken open somewhere? Just seems weird that the open circuit would fail in a way to allow the car to start as opposed to failing and disabling the starter. This seems like it would mean if you could turn the ignition without the key, it would startsince the circuit would be "open" without the key to complete the circuit.
kevm14
Posts: 15245
Joined: Wed Oct 23, 2013 10:28 pm

Re: Fleetwood PassKey II Issues

Post by kevm14 »

billgiacheri wrote: He said it was still starting the car with the wrong reading which was what I was curious about.
Best I can figure is there may have been some momentary contacts with the key and the system is programmed to allow operation, but alert the operator that something is failing.
This doesn't make sense because he said he measured the resistance of the key and it was not zero, but close to what it was supposed to be. The key would still be part of the circuit if the circuit wasn't broken. Doesn't the key basically complete a circuit that has to have some known voltage drop to start the car? So if the key was being registered as resistance, adding the correct resistance being looked for, plus the key should disable the ignition since the additive would be more, and should have registered as out of range. It seems like the circuit to test was being bypassed, and now with the correct resistance added, it is being accepted. Seems like an open circuit allowed the car to run but had lights on, and Adam "closed" the circuit with the exact resistance, but since something broke in the real circuit the exact resistance is seen as correct since the other circuit is still broken open somewhere? Just seems weird that the open circuit would fail in a way to allow the car to start as opposed to failing and disabling the starter. This seems like it would mean if you could turn the ignition without the key, it would startsince the circuit would be "open" without the key to complete the circuit.
I see what you are saying. So yes, his resistor and the key would be....well either in series or parallel and not the right resistance. So he should cut the wires (or a wire) that goes to the ignition switch to assure that only his added resistors are seen by the VATS module.

I just don't think the circuit was totally open before - it is specifically designed so if you copied the key (but didn't have the right resistor pellet, or no pellet at all) that it will not start or run. So it must have been somewhat marginal rather than completely failed. But he should totally disable that marginal connection because it could cause problems.
bill25
Posts: 2583
Joined: Thu Oct 31, 2013 2:20 pm

Re: Fleetwood PassKey II Issues

Post by bill25 »

it is specifically designed so if you copied the key (but didn't have the right resistor pellet, or no pellet at all) that it will not start or run.
True, but unless the new copied key was a plastic or non-conducting key material, it wouldn't be open circuit. It would be closed circuit, wrong resistance. What happens if you made a non conducting copy...
kevm14
Posts: 15245
Joined: Wed Oct 23, 2013 10:28 pm

Re: Fleetwood PassKey II Issues

Post by kevm14 »

Well the pellet resistor thing is wider than the key. So a regular key with no pellet should be an open circuit.
Adam
Posts: 2245
Joined: Wed Oct 23, 2013 9:50 pm

Re: Fleetwood PassKey II Issues

Post by Adam »

The pellet is severely warn compared to other Pass Key keys I have seen. Which is probably why I didn't see any resistance at the harness with the key in. Its also possible that this system has been bypassed already (using jumpers in strategic locations as described for troubleshooting in the FSM). Remember, I bought the car with ~170k with the light on already.
Post Reply