2001 Suburban light problem

[RobD]

I've got a new-to-me 2001 Suburban, K1500 LS. It was working when I brought it home, but the next day things started acting flakey. I'm guessing it needs a trip to the Dealer, but maybe there is something easy I can check first?

 

Things that stopped working all at once:

Headlights (high, low, and flash to pass), no high-beam indicator on the dash when I pull the lever either.

Fog lights

DRL system

Both key fobs - message center shows "Security" 24 hours a day, key or no key.

Automatic door lock at 35mph, automatic door unlock at engine shutoff.

All internal dome lights. Not the dome override, it's out. None of them work with their buttons or the dimmer switch.

Approach lights in the side mirrors do not activate either.

Rear wiper (not the motor, been changed already) - this didn't work before I bought it, so it existed before all this other stuff.

 

Things that still work:

Running lights.

Dash lights for console, radio, and climate controls.

Turn signals.

Brake lights.

 

I just changed the battery today because it wouldn't start this morning (went dead overnight). That could be related to the 0*F weather going on here in Michigan. Since it was a several-year old Delco battery, I was going to change it anyway. But maybe something is draining the battery - I'll know in the morning when I try to start it again.

 

This is my first suburban (first Chevy truck for that matter) so I need help locating an item to be checked. I did check the interior rear wiper fuse this morning, that is intact. I have not checked the one under the hood - it was a nasty windchill and I was already exposed long enough doing the battery change. But with these other problems, I'm thinking it isn't a fuse. Made the module on the dash that has the lights and rear wiper control? Or because of the security system message, the BCM?

 

Thanks for your help!

Robert

[chevroletmb]

yeah the lighting issues and the key fobs all have connections thru the bcm maybe the rear wiper not sure. check the bcm fuses and have it scanned for codes in the bcm.

[RobD]

Okay, can the BCM be changed with one from another vehicle (one from a junked vehicle) without having to be reprogrammed? If so, is it a fairly easy module to change out, or is it buried deep in the dash and not accessed very easily? I'm willing to try changing this myself unless there are issues that require it to visit the dealer anyway. I suppose the key fobs would have to be reprogrammed into this, but I have the procedure for that.

[chevroletmb]

pretty sure it will need reprogramming. but remember i said i could be the bcm.

[RobD]

chevroletmb - I was referring to the BCM needing to be reprogrammed, so it would know my key fobs and other equipment.

 

I noticed this morning the rear defogger isn't functional as well. The light on the button goes on, but the window never defrosted.

 

I'm just wondering if I should try to have my BCM re-flashed, have the dealer change it, or put a salvageyard one in and take it to the stealer for re-flashing so it knows my equipment. It just depends on where in the dash this module is. If I can change it quickly and easily (no garage, and it's near-zero degrees this week) I'll do it myself and save some cash. I just don't know where it is located in these trucks.

[RobD]

I ordered a new BCM from rockauto.com and it arrives tomorrow. Since this is a GM service part, can I install this into my Suburban in the driveway and expect it to start? I thought I read somewhere that blank service modules will learn the password from the PCM. If not, I'll have to drive it to the dealer and install it in their parking lot just before my service appointment.

 

I realize I'll have to take it in regardless to have the factory options reprogrammed back in. I would just like to verify it works at a basic level before I waste the dealer's time with an appointment.

 

If nothing else, can I hook it up and just try turning on my headlights to see if they come back without issue? Then hook the current BCM back in to start the truck to drive it?

 

Thanks for your help! I had to drive the wife's Caravan tonight for an errand because I've got nothing but running lights.

 

This is what I read about Passlock and a BCM relearn, which is what I think the 01 Suburban has:

In order to initiate the relearn:

 

1. Hook up your scan tool to erase any of the passlock/vehicle theft deterrent trouble codes. If there are any other codes, note them before you erase them, so you may address them after the relearn has been completed.

2. With the ignition key in the “On” position from the code-clearing step, attempt to start the vehicle. At this point, if the vehicle starts, and the security light has not illuminated, a relearn is not necessary, and you’re done. If the vehicle starts and stalls, leave the key in the “Run” position and wait for the “Security” light to turn off. This will take approximately 10 minutes. At any time during this relearn, the light may flash or be on steady. If the ignition switch is turned off at any time during this relearn cycle that the security light is illuminated, the entire cycle must be restarted from the beginning. For most cars, one cycle will be sufficient for the relearn. If the vehicle will not start after the first cycle, then continue the process from step #3 to the end. Most trucks will require that you continue from step #3 to the end.

3. When the light turns off, turn the ignition switch to the “Off” position for approximately ten seconds.

4. Next, repeat steps 2 and 3 two more times for a total of three cycles. After the third time, the new code will be relearned on the next start attempt when the ignition switch is rotated from the “Off” position.

5. From the “Off” position, start the vehicle, observing the security light. If the vehicle starts and runs normally, and the security light is off, the relearn is complete. If the vehicle does not start, check for trouble codes before proceeding further.

[chevroletmb]

i've never tired to start a vehicle with a new bcm without reprogamming so i don't know if it will run.

the passlock relearn sounds about right tho

[RobD]

Just an update: It wasn't the BCM after all. I re-checked the fuses today, and the 10A fuse under the hood for the BCM was slightly corroded and one of the legs fell off. Replacing that brought everything in the truck back to life, except for the rear window wiper.

 

Thanks to everybody for their help.