2001 Astro would not start until now

[Mikes Auto & Fab]

Long story but wanted everyone to know what vehicle was doing in the begginning.

Recently I was working on an Astro 4.3 Vortec that was being driven daily and when the owner attempted to restart the van after shopping it wouldn't start. He had replaced the fuel filter hoping that was the problem but it was not. The van would crank but not hit or attempt to start. The only code pulled from the van was an insufficient MAF reading. The fuel pressure was 58-62 PSI @ all times during troubleshooting. The fire was a perfect blue streak across the plugs.

Everyones first thought was fuel pressure, injector tubing under the intake leaking, crank positioning or cam sensor, security pass-lock in the key and other solutions but all tested ok. I unplugged the injection wiring connector on top of the intake to check for voltage and had none. During all these test the door dinger finally reached my last nerve so i unplugged it. I replaced the PCM and upon installation I could hear a different clicking or pulsing at the intake. I pulled the injector connector once again and and was attempting to check voltage while cranking and the engine attempted to hit. I sprayed contact cleaner inside plug and connector and re-connected the plug and the motor started.

Several times I started the engine and was convinced it was fixed. While I getting ready to put the dog house back on i remembered I needed to plug the door dinger back up so I did. I checked everything on the motor including the coolant sensor plug because I had unplugged it to check it after reading a post about that could be a cause of not starting. So i decided to re-start the engine just to check it again and it started.

I continued to put the dog house back on and the door dinger reached that nerve again so I took the key out and layed it on the dash. After putiing everything back on I attempted to move the van out of the shop and it would not start!!!!!!!!

I tried and checked everything and the key would not get past the pass-lock to restart the engine after taking the key out. It would attempt to start then stall each time. I removed the dog house once more and unplugged the door dinger and attempted to start again and noticed it wouldn't try to start. Security light was on solid and not accepting the password reset attempts. I tried the resetdirections for the key numerous times without any luck other than bad. DOG HOUSE or DOOR DINGER?????????????? Definitely not dog house, there are three plugs on the box (the door dinger) above the radio, one blue, one brown and one purple. I unplugged all three for about a minute and plugged them back in and the started pass-lock sequence again and it started working. After the final sequence the van started and is now running no matter how many times you take the key out.

Summary: 1)Checked for voltage at Injector plug = 0 voltage
2)Replaced PCM and got voltage but motor only attempted to start after unplugging the injector plug. Maybe faulty connection after years of driving?
3)Motor started but when I removed the key from the ignition it would no longer pass the security self test.
4) Computer would not accept pass-lock sequence unitl all plugs was removed from box above radio( guessing this is the VCM on this vehicle) and then re-connected.
Hope this helps someone out there and hope i didn't leave something out, this thing was a real pain in the butt!

[Blue Bowtie]

Excellent information. The serial bus on modern vehicles is going to prove to be a weakness once a little age and wear sets in. You may have just encountered one of those instances. I see this on older industrial controls all the time, and now that the automotive industry has espoused itself to the concept, it has unknowingly opened a can of worms. You automotive professionals had better sharpen up on electronics technology quickly, since the tip of the iceberg is beginning to be exposed. Industrial electronics have used (and mostly abandoned) the serial communications protocols since the '60s. Some still cling to it, but most have moved forward to optical or ethernet.