My friend has a 2001 that won't start and I'm pretty sure it is a passlock issue. It will run for about a second and then die.

It has code P1632 (Theft deterrent fuel disable signal received). It also has P1599 (Stall or near stall detected) and U1000 (Class 2 communication malfunction).

I tried to measure the red/white wire resistance from the yellow to the orange/black wire ground like when I repaired my truck, but I always got 0 ohms.

I also found out that after 3 failed attempts, the car goes into long term tamper mode (10 or 30 minutes). Perhaps this is why I always got 0 ohms.

I found conflicting information about resetting the system. I wanted to wire in my own resistor and reset the system to it. The steps are to attempt to start, leave key in run for about 10 minutes until security light stops flashing, turn key to off for 5 seconds, turn key to start again. Some links said to do one cycle and some said three cycles.

I tried this, but the security light just kept flashing. After 10 minutes, it would do a "flicker" flash occasionally where it would flash twice really fast and then keep flashing normally.

This could be because it was in tamper mode though...

After I gave up, he called me about 15 minutes later and said he got it started. I told him to disconnect the yellow passlock wire and it should work until the battery is disconnected (this trick worked on my truck and is mentioned on many other sites). He disconnected it, turned it off, and it WOULDN'T START AGAIN!!)

He had a mechanic come over and he told him it needs a $400 fuel pump. I doubt this because I could hear the pump every time I turned the key forward. I could also smell the fuel. And the car would run for a second or two. I'm 90% sure this is a passlock problem.

Anyone out there have any tips to help me figure it out? Like how to reset the system if the security light keeps blinking?

 

You went more indepth trouble shooting than I did when had what sounds like the same problem on my 2000 Silvy. I had to replace the Passlock sensor that is located by the lock cylinder (GM part # 88965342). It cost me around $60.00 wholesale price.

 

What is the proper way to reprogram is to the new part? Key forward, wait 10 minutes? Once or three times? Or did yours just start right up with no reprogramming?

 

I believe it was once, if I remember correctly. The truck started then. The only issue that I had was the Security light was still on. I had to take it to the dealer and have a friend of mine re-program it to reset the light.

 

You'll need the Ignition Lock Cyl. Housing Case. It comes with the Pass-Lock Sensor and Lock Cyl. Actuator. Once you install it, it should fire right up. I replace these quite often. I have them in stock and sell about 12 a year..lol. The retail at $101.50. $60.00 is ultra cheap for that item....that's almost below dealer cost.

 

You have to do a 30 minute passlock learn procdure for the vehicle to start if the bcm,pcm or ign lock cylinder are replaced.
Crank, die leave key on ten mins till security light stops flashing,
repeat procedure one second time
repeat procedure one third time
Turn key off and crank vehicle after the lamp times out the third time VTD passwords are retransmitted and vehicle will start and run.