2000 denali obs. wont start no dash lights fixed BCM

[Two000Denali]

Ok while my video files upload I want to type this out. My denali has been a great truck to me.. very few issues throughout the years.

Well awhile back my wipers, radio, windows stopped working. I did a band aid fix on that until today. I re soldered one of the spots on the circuit board of the BCM. Which that did fix that issue.

Now the reason I finally got everything apart and attempted the fix was as follows; the truck had worked fine with the band aid fix until about two months ago. I drove denali about a 2 hour trip to go camping and 4 wheeling. No problems. Come home and drive truck for another day. Wake up next morning to leave and truck wont start. Has plenty power, cranks fine, hear fuel pump, starts for half a second and then dies.

I notice NONE of my lights on the dash are coming on. My understanding the SES light has to come on with key forward which shows that the computer is working fine. like I said no lights at all.

One thing I have noticed in the last few months is that when I lock the doors and the security is on, when I go to enter the truck again I have to put the keys in the ignition and turn it forward or the security starts going off. Before I could swear that when I used my key in the door it would disable the security. I may be wrong but I just wanted to throw that out there to insure no detail left out.




I have tried the passlock 2 relearn and no luck. Also as stated before I repaired the BCM today. I did not notice any other bad solder spots, with success of the windows and radio now working.

I have checked all fuses and they are good.

Any and all suggestions would greatly be appreciated

(uploading videos of what its doing now)

-Evan

 

[Two000Denali]

Click on link to watch videos

- truck starting and then turning off





- what the security light does during the process

 

[Two000Denali]

notice none of the gauges are working either. They don't move and shouldn't be in some of the positions that they are in.



Also wanted to add this to the details too. Like I said I checked all the fuses and they are all good. I've noticed that there is a pretty descent size parasitic draw. The battery will be dead tomorrow if I left the battery hooked up. FYI when doing my testing I have a 10amp charger hooked up and the battery is already charged. Tested battery and it passed the load test.

Tomorrow I am going to do a parasitic draw test to determine which circuit could be the culprit.

Please if you have any ideas or knowledge to pass on to me please do. This is my 4wd winter truck. Thankfully its going to be almost 70 tomorrow in Indiana haven't had any snow yet.

 

[Two000Denali]

nothing? I cannot find any one having this problem online. bcm fixed, no parasitic raw, radio windows and wipers wok fine. Not a single light on in the dash, gauges are unresponsive and are not pointing where they should be. Never had a starting problem, took truck out on 2 day camping trip and then nothing.

even tho I repaired the bcm could there be another issue with it? try replacing with another one?

Does the bcm control the dash lights and all the senders to the gauges? tach works fine. Like I said truck turns ove fine and starts right when you hit the key, but ass soon as it starts it kicks itself off and I get no lights or anything.

 

[bacon612]

Hey. I actually had this issue with mine over ten years ago. I think a dealer sorted it out and I don't recall what it was. Had it fixed under warranty. Used to happen every once in a while then stop Think it may be alarm related tho like you suspect. Super strange. I'm sorry I don't have an answer for you but wanted to let you know you aren't the only one and let you know I feel your pain. Really sucked. Truck had like 60k miles on it and it was happening to me.

Sent from my HTC One M9 using Tapatalk

 

[willxfs]

I have a 1998 2 Door Sport with 4wd. My rig occasionally does something similar but I get all the lights working on the dash board (I think). It will start for a half second then die. I suspect its in the ignition switch wiring harness in the steering column. I can usually get it working by working the tilt steering wheel up and down a few times. Replacing the key switch and harness in the column is on my project list. Good luck.