1999 Yukon Denali. Bottom brake lights, turn signals and energency flashers are not working. I'm pretty sure I'm dealing with BCM issue but thought I'd run it past you guys here 1st. At 1st I was sure it had something to do with my trailer connection since I've had shorts and grounding issues in the wiring before. But since it happened on the road with a full trailer, I took it to a truck and trailer specialist and he checked the wiring for signals and said there isn't any signal for brakes coming from the body and suggested a problem with the BCM.
So....the top brake works, bottom left & right don't. Em flashers don't work. Turn signals started working. Checked all bulbs and fuses. Tailights work. I had some brake light assemblies from my last car. (This is my 3rd 99/00 Denali) plugged them in. Still no lights. After reading about bad BCM symptoms I realized that yes, I had experienced the following;
Power driver's window stuck in open position, turning engine off and on seemed to fix it,
Wipers suddenly stop in up position while operating,
Washer fluid pump sometimes works, sometimes not.
1 time the headlights randomly went out.
Auto headlights sometimes work, sometimes no.
No other electrical ghosts.
And while the next items may be unrelated I did see some people list them as possible bad BCM symtoms too.
Persistant misfire on cylinder 4 even after replacing multiple parts.
Bad MPG avg 10-11 (I've had 3 of these)
Poor engine performance. I've always felt this one didn't have the engine power the other 2 had even though they both had almost twice the milage of 158K.
I looked for BCM and found articles about resetting it, but also about bricking it. I found conflicting information about its location, under steering column and under center console. I found conflicting information in the part number as well.
Where is it located on 99 Denali?
Is there more than 1 part number for this model?
Is there a way to find the part # from VIN without pulling out the center console?
What is the correct procedure to resetting the BCM to prevent bricking (if you can brick BCM on this model)?
I would love a reset to fix the problems so I can pass inspection this month and give me time to find a replacement since it looks like they aren't easy to find for this model.
Thanks in advance for everyone's comments.
So....the top brake works, bottom left & right don't. Em flashers don't work. Turn signals started working. Checked all bulbs and fuses. Tailights work. I had some brake light assemblies from my last car. (This is my 3rd 99/00 Denali) plugged them in. Still no lights. After reading about bad BCM symptoms I realized that yes, I had experienced the following;
Power driver's window stuck in open position, turning engine off and on seemed to fix it,
Wipers suddenly stop in up position while operating,
Washer fluid pump sometimes works, sometimes not.
1 time the headlights randomly went out.
Auto headlights sometimes work, sometimes no.
No other electrical ghosts.
And while the next items may be unrelated I did see some people list them as possible bad BCM symtoms too.
Persistant misfire on cylinder 4 even after replacing multiple parts.
Bad MPG avg 10-11 (I've had 3 of these)
Poor engine performance. I've always felt this one didn't have the engine power the other 2 had even though they both had almost twice the milage of 158K.
I looked for BCM and found articles about resetting it, but also about bricking it. I found conflicting information about its location, under steering column and under center console. I found conflicting information in the part number as well.
Where is it located on 99 Denali?
Is there more than 1 part number for this model?
Is there a way to find the part # from VIN without pulling out the center console?
What is the correct procedure to resetting the BCM to prevent bricking (if you can brick BCM on this model)?
I would love a reset to fix the problems so I can pass inspection this month and give me time to find a replacement since it looks like they aren't easy to find for this model.
Thanks in advance for everyone's comments.
