Quick question for you. I had the scanner hooked up this evening looking through all the modules verifying passlock data, BCM data, PCM data, etc. When looking at the PCM data, with ignition on and car in park, the PCM is showing the "Current Gear is 3". Is that what the scanner data should show when car is in park? I wasn't sure what the scanner should show the current gear is when in park. The DIC shows it is in park.

 

from what I recall mine says that as well but it says in another spot it’s in park. I’d have to look again. Find anything interesting? I recall seeing in my tech II it says crank relay request. Yes or no.

 

This is with Key in on position:

Looking in the PCM module I see the following:
Crank Request Signal - NO
Current Gear - 3
Ignition 1 Signal - 12.7
Ignition Mode - ByPass
Starter Relay Command - Off
Vehicle Theft Deterrent Auto Learn Timer - Inactive
Vehicle Theft Deterrent Fuel Disable - Inactive
Vehicle Theft Deterrent Fuel Disable Until Ignition Off - No
Starter Enable Relay Circuit Status - OK
Has correct VIN #

Looking in Radio:
Theft Armed - Learned VIN
Theft Lock - Unlocked

Looking in BCM:
Key in Ignition - Active
Ignition 0 - ON
Ignition 1 - ON
Key Cylinder Unlock - OFF
Auto-Learn Timer Status - 2550
Lockout Timer Status - 2550
Passlock Data Voltage - 1.274
Security Lamp Status - Off
Seed & Key Timer Status - 2550
BCM is showing VIN Characters 6-17 correctly. (My understanding that this is ok)

 

That all looks good from what I recall. Does it change when you turn the key to start and hold it?

 

No, I am not seeing any changes when turning key to crank. I did find the spot where it shows the IMS switch is in Park, so that makes me feel better that the IMS (Internal Mode Switch / Neutral Switch) is not the problem. I am really at a loss on this thing. With everything I have done and am seeing, the car should crank, but still no go. I did figure out the problems with the brake lights etc not working. In the driver side fuse panel, under the fuses, there is a black cap/cover. In the middle of the cap there is a 7mm bolt. Not sure what is under that cover, but I tightened that bolt and all lights are working correctly again. Not sure if the dealer loosened that bolt when they had the car for some reason, but that fixed the light issue. Any idea what that bolt tightened up? I assume some type of connections. Now my only issue is the no crank issue. I honestly don't know where to go from here.

 

Yeah it is very puzzling as to why it won’t start. I was expecting to see a crank request. The bolt you are talking about is the one that secures the wiring harness plug to the fuse box. I believe there is another bolt behind the fuse panel for the other plug that connects to the fuse block. Glad you got the light issue figured out. Sound like you need to check all connections. I anticipated we were gonna see a crank request at
least. What’s even more puzzling is when jumped out the engine will run fine.

 

Correct, no crank request, but when I jumped starter car fired right up and ran fine.

 

I have some additional thoughts on this and some questions hopefully you can answer and some more testing.

1) The replacement PCM - I wonder if its the correct calibration for the car, there was too different types of security (pass lock and pass key). I noticed in my HP Tuners the PCM database shows you can select wether the pass system uses PWM (Pulse width modulation) the 50 hz square wave to enable the start or Serial. I know this is a stretch but maybe it's setup for PWM and not Serial. I know the PCM has to be working cause it did make the car run, I just wonder if there is some settings issue. Your scan tool should have the cal id for the software. If you create an account at https://www.acdelcotds.com/subscriptions you can put in your vin and see if that is one of the calibrations for your vehicle. located under the Resources menu at the top and then SPS Calibration Information.

2). I recall you saying the the PCM crank fuse is good and has 12v applied when the key switch is in the crank position, however I recommend we check to make sure that voltage is making all the way to the PCM in put on connector C2 Pin 23. I believe this is where the PCM would then display the Crank Request Signal Yes on the scan tool.

3) Have you found any other plugs/connectors loose? There is another plug with a bolt behind the one you tightened and you have to remove the fuse block to get to it, not saying we need to do that yet, but wanted you to be aware.

4) As for the BCM it is functioning and communicating with everything as it appears including the scan tool so the PCM should see it as well. Not sure if can fail in such a way the pass lock data doesn't make it the PCM. However if it does end up needing replaced Rock Auto has one on closeout for less than $100, not sure if this needed dealer programmed or if your scan tool will do it. However I am not saying replacement is needed just yet.

5) When the lightning struck the garage did it blow out your battery tender? Also concerns me the PCM needed replaced making me wonder what else took a hit and damaged.

6) Is there anything else I should know to help diagnose this?

 

Responses to your previous questions/comments:
1) I setup an account as you suggested, but I am not able to get the calibration ID's from that site for my VIN#. My calibration ID for the PCM in the scanner is 49204.
2) I am a little confused on this one. I pulled the PCM connector C2 and used multi-meter and checked pin 23 on the C2 harness connection and had nothing. I did test the C2 pin 23 on the PCM and was getting full voltage when key in on position.
3) I checked everything possible and didn't find any other issues.
5) No, did not blow out the tender. I had several things in garage fried though. Ceiling mounted propane gas heater, it fried the circuit board in it. Several outlets blown and even some of the outlet plates blown off. Some light switch's fried and covers blow to pieces. Security camera in garage fried.
6) Not that I know of. Only thing I am seeing is not getting ground signal to crank relay from PCM. All wiring checks I have done, such as the continuity of the wire from the PCM to the Crank relay terminal for ground signal is fine. Security relearn seems to have worked fine, because security light is off after relearn process, but it is still like there is a problem with that passlock. I already changed the entire ignition switch (Key lock, cylinder, and module) with all OEM GM parts.

 

Thank you for the reply David and checking all that. I am surprised the VIN calibration ID lookup didn't work. I am confused with item #2 as well. That should only have voltage in the start position only. Are you able to take your meter probe and stick it into the back of C2 Pin 23 in reference to ground while someone turns the key to start you get no voltage? With it unplugged and testing you should have gotten 12v in the start position only. So weird.
WOW that was some serious damage done by that lightning strike. If we do confirm the crank signal is being sent to the PCM then it must be something with the padlock not making it to the PCM, but all modules are communicating.