GMT-800 Body Control Module DIagnosis Silverado, Sierra, Tahoe, Yukon

GMT-800 Body Control Module Diagnosis on Silverado, Sierra, Tahoe, Yukon.
In this video, we talk about checking for a faulty PCM that all signs point to a bad BCM.
gmflash.com/bcm
GMFLASH.com
SpartanAutoworx.com
636-795-6960

[@vitoconsiglio5307]

You've mentioned pcm and bcm, are you talking about both or just bcm ?

[@dubcoco1]

I have an 01' Sierra 2500HD with the 6.0 gas. The fuel gauge works, then not works. The airbag light is on and check engine, ABS lights are on. It will sometimes not start from the security. I disconnect the battery for a bit, it cranks back up. I watched your other vids and pulled the BCM. It has a reman'ed BCM from AC Delco. The radio works fine and runs fine until it decides not to. The fuel gauge is on-off constant.

[@JB91710]

Forget about almost everything I said in my other comment. I had mentioned that some stuff would come back on when I made a tight turn to the left or hit bumps. So, in desperation and frustration, I drove around a bumpy parking lot making tight left turn and everything came back on and stayed on. I parked the truck and started thinking about something loose in the steering column. Then I tried to start it, and nothing happened. All the body stuff came back on, but the engine wouldn't turn over. IGNITION SWITCH????????? Update! No! 1. Driving along and everything inside the car goes dead but the 2005 Tahoe keeps driving. 2. I make a hard left turn, and everything comes back on but then dies out again. 3. One day the starter would turn over but wouldn't start. Everything inside is dead. 4. Remembering the left turn deal, I put the key in the on position, everything still dead, I opened the door, grabbed the edge of the roof and started rocking the truck. The interior lit right up, and the radio came on and I was able to start it. 5. The problem would resurface. Do you think it could be a motion detector that is acting up? I have a blank key that will start the truck. Did the previous owner bypass the passkey system?

[@markfanara9493]

This is the "advanced" troubleshooting video. Do you have the basic troubleshooting video? I need to confirm the BCM is the problem I am having.

[@CCCC-tq8yo]

5 yrs later

[@shannoncarroll3600]

Hi I've got a 2015 gmc sierra 1500 I ordered some led headlights from Amazon I took the regular bulbs out and plugged the led bulbs in and now the truck won't crank or start when you switch it on every thing comes on when you turn the key to Try and start it everything goes blank and when you let off of the key everything comes back but it won't crank or start I've checked every fuse and relay and every one of them is good I didn't find any of them blowed any suggestions and I've tried to jump it off and still didn't work

[@JB91710]

I FIXED IT!!! I don't know what caused the problem, but I know where it originates so now, I'm having trouble duplicating the problem. 2005 Tahoe. Follow the Parking Brake Release cable as it curves around a small black box. Moving that cable off the box made everything come back on but eventually it went off. Giggled the box and it came back on. Pulled the box out of its holder and giggled the connectors and then put it back in. The pressure of that cable against the corner of that box could have disconnected something. I'm going to loosen the bolts holding that cable to get it off that box and see if that keeps it working. I'm inside now trying to look up what that box is as it is Not the BCM.

[@SpartanAutoworx]

Box mounted on the floor?

[@JB91710]

@@SpartanAutoworx No, it's behind the brake release lever in a galvanized metal bracket. It's the size of a box of bank checks. The cable raps around it and was pushing it to the left and must have shorted it out. I drove it for an hour and the problem never came back.

[@lanzonests]

So I have a 2001 chevy Tahoe 175K miles. service engine soon came on BCM "B2722" transmission preference switch circuit low and Electronic brake control module "C0265" EBCM motor relay circuit. should I replace both modules?

[@peted11956]

I have an "05" Suburban and it has a constant 2 amp drain on the battery, so when I shut it off if it sits overnight it's dead in the morning. New and good battery. I've been checking by pulling fuses from under the hood and trying to locate the cause of the drain. So far it's one of the 40amp fuses under the hood and that's the ignition. That's as far as I got since it's winter time and I just unplug that fuse when I get home and plug it back in when I go somewhere. I did notice once or twice, that my remote start and door unlock didn't work and like to never got back inside my truck because the door locks were frozen. Finally got the key to open the door and sprayed some spray into the door lock so that wouldn't happen again. I'm just wondering if maybe the BCM could be causing this. The other thing I noticed is the low tire light comes on often but the tires aren't low. As soon as it warms up some more, I can check some more fuses for battery drain. I need to check the ones under the dash next. Anyway, just wondering if this could be the problem?

[@SpartanAutoworx]

Start here kzbin.info/www/bejne/pqnInJ1oj6eUY7c

[@coreystevens9392]

I'm having an issue with the rear wheel sensor not being recognized, the truck digging when I hit lock button leaving the truck but not locking unlessing hitting it again, the garage door buttons not working, and can't program key fobs. Would this lean towards being the BCM?

[@Amechanical7]

I picked up a bcm from a suburban for my crew cab truck. Did the 30min key relearn and now the truck starts? Im currently trying the bcm “handshake” but not sure it will work now? What went wrong

[@JB91710]

2005 Chevrolet Tahoe. A lot of interior systems are out but the truck runs fine. Gauges are down, warning lights are on. When I make a hard left turn, some things come on then die out in one or two seconds. Today, I turned the key on, and everything came on and worked and then died a few minutes later. Then the gauges cluster went completely dead and then some things came back on in the cluster. The battery did run down to 11.4 after being parked for two days and even with jumps it wouldn't start. A new battery and it started right up. I have found the new battery at 11.8 overnight. The alternator is charging strong. If everything went off and on, I would think it was a ground. What would you say it is if there are a mix of things being affected and then coming back on? I haven't checked for corrosion yet.

[@SpartanAutoworx]

Do you have com with scan tool?

[@JB91710]

@@SpartanAutoworx I bought an Ancel AD530 but all it showed was a code for a cat issue. Then it showed error when I tried to reconnect it. Didn't say anything about the BCM. What's com?.

[@JB91710]

@@SpartanAutoworx 1. Ever since I cleared one unrelated code with the scanner, it won't connect to my Tahoe. Keeps coming up with "Fail." 2. This morning the battery was at 12.7 before I started anything. Yesterday it was 11.7. This is the new battery. 3. I found the BCM was Not locked in place, so someone was in there. This Tahoe had $8k worth of damage from the previous owner so some reprogramming work might have been needed. 4. I have owned it since 12/21. Only electrical issue has been reading lights don't work. Once they did work when I was in the back. Maybe they only work when the vehicle is turned off. 5. I pulled all the connectors out of the BCM and there is no corrosion. Perfectly clean. 6. I opened and inspected the BCM. Every connection looks factory new. 7. Here's a symptom. When I make a hard left turn, the radio and some other items come on for a second or two and then die out again. But only some. Loose ground? Should my next step be to disconnect the battery ground and connect it to the positive pole with a 10w 1 ohm resister and drain the residual power out and then reconnect it?

[@JB91710]

@@SpartanAutoworx The scan tool makes no reference to the problem.

[@onemoremisfit]

I have a 2002 Avalanche 5.3L with running engine but dead instrument cluster and numerous interior malfunctions, also my tech 2 scanner says no comms. I have checked & cleaned the PCM terminals and they look fine. I listened carefully to the segment between 3:00 and 4:00, and it sounds like you say check & clean the PCM terminals, and see if the interior functions work with power on and PCM removed, which makes sense. Then it sounds like you say disconnect the BCM and start the engine with only the PCM connected, and if the engine runs OK on the PCM only, with BCM disconnected, then that indicates a bad PCM? Am I getting this right because it does not make sense to me. Do you mean to say that the engine should NOT start with PCM only and no BCM, and if the engine does start with PCM only then the PCM is bad? How is that so?

[@SpartanAutoworx]

Disconnect the BCM try and start the vehicle the vehicle should stall and die. If it continues to run without the body control you have a shorted PCM

[@onemoremisfit]

@@SpartanAutoworx Thanks, I did do that and the engine cranks, barely sounds like it wants to fire but stalls, just like you say.

[@keithsparks7809]

You mentioned a prior video regarding bcm analyzing for weird electical issues. I have a 2007 escalade ext that has the random guage cluster/door lock clicking/stabilatrak - traction control messages. Teuck can runs fine any where from 25 minutes to over an hour before it starts acting up. Get an U0073 control module bus comm off message DTC after it starts having the issues. Replaced ecm with a dealer programmed unit. Would tou post link to the other video? Didn't see it mentioned and video description or comments. Thanks for any help!

[@SpartanAutoworx]

Is that the only code you have?

[@keithsparks7809]

@@SpartanAutoworx P0700 transmission control system malfunction. That is it. I figured that code was due to it not able to get information from the gauge cluster. Truck was running fine, discovered that it had bad motor mounts, so replaced them. Not too long after that, started acting up. Started checking obvious things (ground wires). Negative battery cable ground was severely rusted out inside the cable. Looked fine from outside. Replaced it and went ahead and replaced positive cable as well last week. Drove fine for about 30 minutes and then started acting up again.

[@rickk3748]

I have a 2003 avalanche where once you start it up it seems fine but once and a while the abs, gages, chiming, etc will happen. Most recently it will go crazy when I put it in gear. Even causing my passenger headlight to go out. Then sometimes my 3rd light comes on, have no brake lights, and if I use my turn signal I will loose power. I have done the grounds under the driver, new ignition switch, new turn signal switch during to cruse quit working. This was a temp fix now only works internet. Looking to stop chasing the tail. Your thoughts would be most appreciated and helpful!

[@SpartanAutoworx]

I would say BCM shooting from the hip without codes or any further diagnosis

[@cobynunn1543]

I got a 2003 Chevy Silverado and I have a BCM code B2575? Everything works besides my low beam headlight... I looked under the fusebox and it was good. I took the relay out and put a piece of wire and put the relay back in. I took the other end of the wire and grounded it to the frame and the low beam lights came on. If I take the wire out and put the relay back in they won’t come on. They’ll only come on if I stick a piece of wire in the relay and ground it against the frame...

[@howellnolte7343]

I have a 2004 GMC Sierra extended cab I have a very strange issue with it I've replaced numerous parts including the pcm I'm thinking its its possibly the bcm but some things effected are not supposed to be in the bcm's operating system so here's what's going on it started with the left fog light quit working then it randomly went into limp mode reading code for dbw throttle actuator I replaced it then a few days later it set the code again so it said replace the dbw controller so I did still had the problem then it read the ecm was faulty replaced it cleaned grounds added some also then it wouldn't clear the ses light unless the headlights are off checked all headlight wiring found no problems then I noticed it looked like the lt headlamp had both high and low beam illuminated so I unplugged the left low beam with it unplugged the ses light clears with the headlights on while checking the wiring harness I unplugged the left high beam and the truck would turn over but not start I plugged the lt high beam back in and it started right up so I'm curious if you think the bcm could create these issues I had a shop look at it and they were at a loss and said they didn't have a clue

[@boudrouxatnightg2144]

Hey bro we just had a bad lightning thunderstorm and a tree near my 07 tahoe got hit when we came outside one front running light was on and one of the break lights was on!! Truck starts up and runs but I don't have blinkers and they don't even show up on the cluster when turned on. The headlights won't switch to high beams or even show up on cluster. Ever seen this before after a lightning hit something near a 0t tahoe. To make matters even worse it also screwed up my hvac on my house lost the condenser fan motor or either the capacitor or both so no ac in the house tonight either so I got 2 big problems from this storm now I need help with the tahoe I work on hvac systems so I'll get that looked at in the morning.

[@SpartanAutoworx]

Probably looking at bad BCM

[@boudrouxatnightg2144]

@@SpartanAutoworx yeah that is exactly what it was i went and got one from an 08 yukon and swapped them out in about 10 minutes and everything works again including my keyless entry did not have to have it reprogramed either to my surprise because i had aftermarket stereo system

[@brianreilly1214]

I have an 03 Escalade base. The key fob won’t unlock, rear wipers don’t work, rear access open message. Truck runs beautifully otherwise. There is a grounding block? on the inside of rear passenger fender that has four connectors plugged into it. The blue connector has corrosion on two of the pins and corresponding dark areas on the connector. Any thoughts and do you have a good bcm available if that’s what you think the problem is? Thanks!

[@SpartanAutoworx]

Check grounds first if not most likely a bad bcm.

[@LesoisKurios]

I have bcm codes but no issues inside except for the seat heaters... another things a previous owner of this 03 z71 tahoe .. splice in some wiries behind the dash near the bcm for a DVD player and old school stereo blue tooth adapter the one that you use with the stock stereo fm station what could be the issue.. ive checked the connections.. im thinking about taking it out completely and cleaning the connections next

[@SpartanAutoworx]

Check the seat heaters with a volt meter

[@noseraja4615]

My cluster is out it illuminates and shows check engine, i plug in my scan tool and it powers the tool but cant communicate do you know what it could be, ive tried several clusters so i doubt its the cluster

[@SpartanAutoworx]

Do you have both ignition and battery voltage going to the cluster

[@urownjones]

2007.5 after egr delete with all new pipes the mechanic says he cant get obdii to register and truck wont start. Windows won't work volt meter is dead...lights come on and the ignition dings but not a sound when key is turned. I originally had a tune that only turned off the egr and left hard stock. Now it's all new and wont start. We didnt know the tune it had in it when we bought it but it seems to have been his mini max due to the wiring and box left installed under the dash. They just took the monitor. I'm not sure if the mechanic tried to tune it and it failed but I'm gonna need some parts.

[@SpartanAutoworx]

If you have no crank no start with no com sounds like a bad bcm.

[@Mrgulaman]

I have a 2008 escalade. Right turn signal hyper flashes. I cleaned the ground under the truck and no luck. Tested wires and wire harness and they are all getting power... not cutting off when I wiggle them. I do hear the rear tail light making a buzzing sound when the turn signal is on. Also during the evening, when i press the unlock on the key fob, tail light has no parking and reverse lights but when I start it, lights turn on. Also I noticed when the right turn signal is activated, interior lights slightly dim with the signal when the door is open... Is this the BCM? Thanks

[@SpartanAutoworx]

Sounds like it. Tail light making a sound? What kind of sound?

[@tomchristensen2914]

I noticed last night after I replaced my reprogrammed pcm. that my lights around radio and temp controls the night time lights would go off when either map light was pressed of visor mirror is opened. the lights of map or mirror wont come on at all but other lights go off. they come back on when you turn off or close mirror lid. is that a bcm issue or do I need to do a relearn on bcm

[@SpartanAutoworx]

Something does not sound right. I dont think its BCM related or ECM related. Would need more info. Drop me an email with year make and what all has been done and any info to help diag it. When I get some free time I will check it out and give you my Remote Crystal Ball Opinion.

[@deepee9601]

My doors don't look or unlock,my gas needle don't work my windows don't go down or up battery light say on oil pressure and temperature gauge don't work is this caused by BCM on a 2003 Chevy Tahoe

[@awesomefish100]

Did you find out the issue?

[@deepee9601]

​. I sold the truck two years ago they said it was the way I hook up the radio up with the outdated radio wiring harness the guy mechanic fix it I miss that Tahoe 😢

[@richardjenkins6342]

If I unplug my bcm fuse. I can’t start my truck. But my bcm fuse circuit has a parasitic drain on it

[@SpartanAutoworx]

Drain should go away with fuse pulled

[@Itsoundslikethat]

So if pcm is cleaned and then put back together and then disconnect the bcm and if it starts and nothing inside works it’s the pcm is bad? Or did you mean to say bcm is bad?

[@SpartanAutoworx]

Bcm disconnected and it starts bad pcm. Truck should not start without Bcm

[@insideoutsideupsidedown2218]

Everything works inside my truck except my keyless entry will not function anymore. I have bought new fobs and tries to program them with no luck...is the BCM the issue?

[@nismor3490]

Will be trying to figure out what is going on with my truck...get the dreaded security light and wont start unless i do the relearn....it gets annoying but love the truck and want to fix it!

[@SpartanAutoworx]

Year make and model?

[@nickiadams7778]

I have an 05 Tahoe. I can only get 3/4 tpms to pick up, “service tire monitor” on instrument cluster, and cannot get new key fob to program. Would this be the BCM??

[@SpartanAutoworx]

Could be remote control door lock receiver

[@JesusOrtiz-qp1so]

What’s the shipping cost to San Francisco Bay Area

[@SpartanAutoworx]

Probably between 10-15 but without weight dimensions of box address that’s just a guess could be more

[@artm0011]

I have a 2004 Chevy suburban 5.3 v8 recently my anti theft light abs light check engine light battery light came on also the unknown driver message was on my display and the all my gauges stopped working also my windows won't roll down and the door won't lock or unlock can this be the bcm?

[@SpartanAutoworx]

Most likely is. Unplug the BCM try and start the vehicle. It should not start. If it does with the bcm unplugged then you have another problem.

[@gio94sr20ve]

Art Maldonado I have the same issue with my 2005 avalanche. Did you ever find the issue ?

[@rickbaker9053]

Did you ever find your problem by chance?

[@CookieAte]

04 silverado, disconnected bcm but everything inside works. Code P1626 in pcm(numerous attempts to relearn) never takes. No comm with bcm when plugged in. I have 3 bcm and none make a difference.

[@SpartanAutoworx]

Unplug airbag module report back

[@mrdeanv4414]

Great video and very informative..! I have a 2007 Ext Cadillac..any chance that you can tell me why my backup/reverse lights stay on? I replaced the brake switch on the brake pedal...someone said the relay to the backup/reverse lights burned out in the ON position but I cant find the relay... someone else said that the relay to the backup/reverse lights is in that little BCM black box?

[@SpartanAutoworx]

Could be a bad bcm. Scan bcm for codes.

[@mrdeanv4414]

@@SpartanAutoworx Thank you very much..

[@mrdeanv4414]

I ended up pulling the Fuse to the backup lights... here in Tx we don't have to have them to pass state inspection.... I still have the 07 Ext Escalade.. it has over 200 thousand miles.... I did replace the on board compressor and rear airshocks... will be replacing the front magneride struts very soon

[@Gizzmoization]

2003 gmc yukon battery died jumped.it replaced battery no start no crank all lights work radio only light is engine check shows up on dash any ideas?? When jumped the alarm went off and key fob did not work but now it works just wont start truck

[@SpartanAutoworx]

Should crank even with bad electronics. I would start with wiring at the fuse box.

[@Gizzmoization]

@@SpartanAutoworx will do thanks

[@jeddy1984]

Would a bcm prevent the truck from shutting off when the ignition is off and key removed in your opinion?

[@SpartanAutoworx]

Unlikely

[@jeddy1984]

@@SpartanAutoworx thanks

[@stephanhild3669]

Did you figure the ignition thing out. My door locks keep unlocking and locking, headlights and constantly flash, and many manufacturers other intermittent issues after driving my 07 silverado 5.3 for about 10 minutes each time. I'm convinced it's BCm and I had a locksmith change my ignition out. But I can take the key out completely after turning it off but it stays running. So I pull the run/crank relay to turn off. So I was seeing if you figured it out.

[@jeddy1984]

@@stephanhild3669 I have an appointment with a dealership Tuesday. We will see what they find. I've had my wipers come on for no reason and a low coolant message even though it full.

[@thewonn]

I need a BCM for a 2003 hummer h2 part#15198179....do you have one, and can you program it....

[@Genob420]

Can you program a bcm for cruise control? 2008 gmc Sierra thanks

[@darrellstokley1686]

Do you have one for a 08 Cadillac Escalade ESV AWD V8 6.2

[@SpartanAutoworx]

Drop me an email with info Spartanautoworx @ Gmail .com

[@darrellstokley1686]

Sorry I already got one a week ago but I didn't put it in yet but I do need a active suspension control module and the connector in I need a BCM ASAP. programmed

[@michaelwilliams8967]

Can the bcm cause my courtesy lights to flash every 15 seconds? When door is open or when I unlock the truck with the key fob? 2011 1500 silverado crew cab

[@SpartanAutoworx]

Possibly. I would check door contact switches first.

[@jasonlorick3898]

I have a 06 Impala. See some wires shorted under seat. Fixed them now seat windows and locks won't work. Also flashing airbag light on dash.. could that be bcm

[@SpartanAutoworx]

Could be what codes do you have?

[@salvatorem740]

How do you scan BCM?

[@2wrdr]

Just beginning the learning process here but isn't' there more than one BCM?

[@SpartanAutoworx]

Many Modules but only one Main BCM

[@dannyhowell558]

Will you ship to Canada

[@SpartanAutoworx]

All day Monday - Friday we ship worldwide

[@j.p.6229]

Will you be able to programed my control module to a keyless entry ? Is a 2000 silverado regular cab

[@kakis84559]

cool video man i have a problem i got a 2003 tahoe 4.8 have no crank everything else seems to work ok but the line under the cluster where it shows PRND321 isnt there it started as an intermittent now i cant get it to crank at all and the oil and fuel guages are at lowest setting when it started i would try key couple times and it would work after couple times now i am not getting any crank anything you think i should replace the bcm or pcm i will check all connections this weekend and will update anything i find.

[@kakis84559]

oh forgot to add i put a new ignition switch, neutral safety switch on trans, a new throttle position sensor and a new battery, new oil pressure sending unit, and I replaced all the cluster step motors.

[@AlexManion]

Did u figure it out mines doing the same

[@willmack2891]

I bought a new bcm it didn’t work I’m in houston Texas please help the one I got doesn’t work on

[@SpartanAutoworx]

Need more info. Year Make Model Ect

[@giraldovalle2355]

2011 chevy silverado 3500 hazards keep going on no sound but cant control no lights

[@SpartanAutoworx]

might be a bcm

[@texas3258]

I checked my pcm found some type of liquid goo blackish color when I took my connecters off

[@SpartanAutoworx]

Sounds like the PCM let go or had some kind of water intrusion.

[@tagineladide1]

thanks for the info

[@frederickhowe3464]

Is Power Control Module the same as Body Control Module

[@SpartanAutoworx]

Frederick Howe Power control is mainly referred to as the engine computer pcm

[@frederickhowe3464]

thats different from the video?

[@SpartanAutoworx]

Yes

[@TrannyWorshipingJew]

Don't normally comment on things like this but do you realize how many time you said "I want chyou to....." Gets a little screeching on the ears

[@charliekersey2576]

BCM= Body Control Module PCM=Powertrain Control Module They are not the same. However they do communicate between each other. One is mainly for engine/transmission control PCM and the other is for exterior lights, wipers and interior electronic controls (BCM). They also have in other makes and models ECM= engine control module and TCM= transmission control module. SO IN SHORT THEY ARE NOT THE SAME.

[@algagne9410]

2005 Tahoe. When I bought it the previous owner had just had a new aftermarket radio installed. When it was installed the interior lights stopped working. Door card lights still work. Also, the drivers heated seat has a mind of its own. It comes on/off at will. Is this a BCM issue??

[@SpartanAutoworx]

BCM / Driver seat module / Serial data wiring. 1st check for any splices from radio to the serial data line. I have seen this on many trucks with aftermarket radios looking for a serial data signal. Undo the tap to that line if found. 2nd unplug driver seat module and see if any conditions change. That is also serial data driven and can cause other issues with the truck when it fails.

[@dailygrinders89]

idk what my truck is doing but a buddy of mine said it could be the bcm. I'm getting the message right rear door ajar while driving even though it's closed and also my door locks are locking and unlocking constantly while driving. could this be the cause of a faulty bcm?

[@SpartanAutoworx]

Yes thats the BCM failing.

[@jrr1631]

I'm getting unknown driver out of no where slammed my passenger door and now my truck won't start

[@2Jeezuzisreal]

BCM or PCM

[@Dev_Golfs]

Having a huge problem and really need help!!!! I accidentally touched my positive and negative wire off of my amplifier in my truck. Right after that I’ve had weird electrical issues. Windows don’t work, blinker arrows stay on in cluster and get brighter when I press the window button & almost my hazard lights turn on when I press the brakes. Can this be the bcm?!?

[@Dev_Golfs]

@The Man Delorean yup, just needed a gallon of gas and a lighter.

[@CCCC-tq8yo]

3 yrs later what was it

[@Dev_Golfs]

@@CCCC-tq8yo radio was wired wrong, work perfect after I removed it and put stock one back in.

[@JoeCnNd]

I got this dang anti theft light on. It's from jumping another car. trying to chase down where the heck it's coming from.

[@mathewduncan2646]

I need a bcm for a 03 2500 duramax

[@freddycabanas3582]

I need a BCM for 2007 Chevy Silverado 1500

[@JoseMedina-ph5oy]

arreglaste tu problema yo estoy en lo mismo

[@jrr1631]

I need to contact you