No crank/start after replacing intake manifold. Security lock out?

[CAPT75]

Totally stumped again. A while back I posted about replacing my cylinder head when I was misfiring due to a bent intake valve. I was getting weird messages on the gauge cluster info screen, no crank/start, and power to some but not all accessories. I replaced the starter, no change. Ignition switch is good as far as I know since you can hear the relays in the fuse box, so I finally replaced the battery, under hood fuses/relays(starter, run, crank, etc)and did the 30min key relearn process and it started running again. When I put it back together it was mildly misfiring again due to what I thought was a cracked intake manifold because I know I overtorqued it. Easy enough, I ordered a new intake manifold, installed it with the new gaskets I just put on last time, new o-rings on all the injectors, plug everything back in (not much), go to start it and nothing.

Same weird computer issues again. I try to start it, no crank, I get “stabilitrak off”, “traction control off”, “park assist off”, & “service suspension system” on the DIC, there is no indicator dash under PRND12 to tell me what gear I’m in (it’s in park), and the abs, engine, and traction control lights are on. Power windows work, power door locks do not, power running boards do not, dome lights don’t come on when I open the door, HVAC comes on, nav/radio comes on. If I put my foot on the brake and can move the shifter through the gears whether the key is in or not (not sure if that’s normal, never tried before). If you guys have any ideas what kind of computer issue this could be and how to resolve it, I’d love to hear it. I’ve tried the 30min key relearn technique about 8 times now thinking maybe I screwed it up and still no luck.

 

[thompsoj22]

Just what id try. 1st, The key/ign must be off for at least 15 min. have the hood allready open, do not open any doors. 2nd, disconnect the battery and leave disconnected for 15 min. after 15 min has elapsed lift the bails on the underhood fuse box and inspect the connection interface underneath, all good? reinstall firmly and clamp bails down. reconnect the battery open the door and try to start the vehicle. It is amazing how power interruption can completely fubar these vehicles! Is the **** fuse good? i would not suspect security system based upon the maint performed. Is the key the original? has the key ever done this before?

 

[camaroz2887]

Thompsoj has a point.

Maybe the battery-/ engine and engine/chassis grounds got messed up during the work. Gmt800s have a pcm/whatever module ground up on the firewall too dunno if they changed the location with the 900s.

good luck

 

[CAPT75]

Unfortunately I started the work, thinking it’d be a quick fix, as we were starting a move into our new home. So painting, flooring, carpet, unpacking, etc, sidelined getting back under the hood and it’s currently stuck at my parents house. I’m hoping to get over there this weekend and try what Thomsoj22 suggested. I don’t think any grounds got messed with, I know there’s one on the front of the block, and the back as well on the driver side head, neither of which were touched. I checked the module on the firewall last time this similar situation happened and it was fine. I also didn’t mention the alarm fob doesn’t work at all either. Replaced the batter my just in case and it made no difference. This is also the original key, never have had any new ones made. There is a spare and it’s still the same issue. I feel like the situation was identical when I reinstalled the repaired head, I think the messages were different on the DIC but I can’t remember. That’s when I did the 30min key relearn procedure and put in a new battery and it started. Doing the same thing gets me no where this time.

 

[donjetman]

Security Relearn - here is procedure I found on a local tuners website.

ATTENTION: Your vehicle may not start unless this procedure is performed. If your vehicle’s battery is low, it is recommended a battery charger be hooked up at this time. You may want to be outside your vehicle so shut the door, roll down the window. As it will take 40+ minutes to go through the cycle.

PROCEDURE:
Attempt to start the vehicle.

The engine will turn over, possibly start and die, LEAVE KEY IN THE ON POSITION for at least 10 mins or until the Security Light turns off. The security light may blink a few times, then hold steady.

– some vehicles may not display a security light, be sure to keep the key in the ON position for at least 10 mins after each start attempt.

When the Security Light turns OFF, turn the key to the OFF position for at least 20 secs.

Repeat the previous step 2 more times, for a total of 3 start attempts and 3 key off steps.

On the fourth start attempt, the engine should start.
If any step is done incorrectly, you must start over.

 

[CAPT75]

Awesome, I’ll give that a try as well. It seems that these steps are very specific, and I have yet to try that process. Probably why I’ve had to try it so many times.. if it isn’t perfectly executed, it doesn’t work. Thank you! Crossing fingers.

 

[ScottTheEngineer]

Ground strap on the back of the engine is off. You had to remove it to get the head off and forgot about it. At least, that's what I did to cause that same thing.