Hello, I'm having a bit of an issue with my fiero that I'm having trouble figuring out. I was unable to turn off passkey in hptuners on the 2003 pcm despite setting VATS to pwm and turning off 1626,29,30,31. When I plug in my spare 99 gtp pcm the car runs but won't shift into 3rd. The guy who built.my harness said he wired the harness so it can he used for any year transmission, but from what he knows the pcm year needs to match the transmission year. I can tune both the 99 and the 03 pcm. I did try to overwrite the tune completely on the 03 pcm, but the car still just cranks and won't start.

Two weeks ago my Passkey quit working on my 2001 Camaro with 82 k miles. I had a 94 that had the passkey quit and I didn’t have a clue what the problem was. Had it towed to a shop and they explained the problem. Nice guys, they let me add the bypass resistor to the harness, while I was in their parking lot. After Radio Shack closed, I was able to purchase a complete set of resistors for every passkey. Since you probably don’t have the original key to verify the resistance, you could buy the set ( around $ 15 on EBay) and try each resistor till you get the car to start. Sorry for the long winded explanation, it one of my many bad habits.

quote Originally posted by jhobbins: Hello, I'm having a bit of an issue with my fiero that I'm having trouble figuring out. I was unable to turn off passkey in hptuners on the 2003 pcm despite setting VATS to pwm and turning off 1626,29,30,31. When I plug in my spare 99 gtp pcm the car runs but won't shift into 3rd. The guy who built.my harness said he wired the harness so it can he used for any year transmission, but from what he knows the pcm year needs to match the transmission year. I can tune both the 99 and the 03 pcm. I did try to overwrite the tune completely on the 03 pcm, but the car still just cranks and won't start.

There are significant wiring differences between the 2003 trans and earlier trans, it's not possible to wire the harness to run both versions of the transmission.
I would suggest verifying the correctness of the harness as your first step in correcting your starting issue.

quote Originally posted by Eliredandblack: Two weeks ago my Passkey quit working on my 2001 Camaro with 82 k miles. I had a 94 that had the passkey quit and I didn’t have a clue what the problem was. Had it towed to a shop and they explained the problem. Nice guys, they let me add the bypass resistor to the harness, while I was in their parking lot. After Radio Shack closed, I was able to purchase a complete set of resistors for every passkey. Since you probably don’t have the original key to verify the resistance, you could buy the set ( around $ 15 on EBay) and try each resistor till you get the car to start. Sorry for the long winded explanation, it one of my many bad habits.

There is a VATs module under the dash that the resistor wires to. No, you can't just wire a resistor to your PCM and have it function. You would need both the VATs module and the resistor. A simpler solution is to ues a VATs signal generator. The VATs unit under the dash creates a signal that the PCM needs to see for it to think the right key is inserted. THe VATs unit under the dash is programmed to only work with a specific resistor that is located in the individual key. There are contacts in the ignition cylinder that connect to the resistor in the key. If the right resistance key is inserted, the VATs module under the dash will send out the right signal to the PCM and the PCM will fire the injectors.

This unit produces the VATs signal the PCM needs to run. Locate it near the PCM. Wire it to the same switched voltage that the PCM gets. Wire it's output to the VATs input of your PCM. You will have to see which frequency the PCM needs, but it will be either one of the other. And then your engine will run.

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Typically, even with VATS not disabled, the car will start and run for a second, and then die.

Check your wiring at the ICM....