What's up mr bill, do you have the list for this chevy it's out here? Oh this list, this. Thank you there. We are folks the 2002 chevrolet, it's the tahoe, it's got the 5'3 and it smells like frustration. Actually, when you sit in it smells more.

Like anger, i don't know why, but that's the juju it's putting off anyhow, i got the list and he writes. Tahoe will not shift at transfer case no light on dash long story short as they say the buttons don't work. It doesn't go into four wheel drive and then he writes uh, it's been at the napa service center. They charged me 1200 did not fix it.

Then it was at a shop in corning for six months for one thousand dollars did that fix it. So so far he's up to two thousand two hundred dollars and still has no four-wheel drive uh. This started not shifting, then intermittent acted like it was in four low when it was in too high transfer case acts like only three detent and oil has not been changed in case. I'm not sure what that means.

Uh tahoe has a new front, diff front. Actuator works three-year-old transmission left front shaft new brakes, rotors plugs coils, injectors map, sensor, mass air flow, air filter, fuel filter, fuel pump, charcoal canister, muffler tail pipe tires battery fuel cap, push button transfer case, control, module, transfer, control, motor wires, trace, ground's, fixed and fuse is Checked and lucky you, the front made some loud clicking sound like it was trying to shift when not prompted to over. If this is reasonable, fix fix it if it needs a transfer case i'll put one in the summer. Thank you for your time impressed with your troubleshooting skills, love, always jay anywho.

So that's where we're at. I keep this stuff right here. I'll show you, where you put this right in your back pocket and you kind of keep it in your memory. But you forget about it: we need to go ahead and find out.

Why find out what's wrong with it find out why the transmission trigger or the transfer case won't shift into four wheel drive um there's a lot of parts inside the drive. Shaft lays in the back to transfer case control modules in the cup holder and the dash's torque part like i say it smells like anger. What we're gon na do, what our plan is. You always got.

Ta have a plan plan to work work. The plan we're gon na plan on doing this. The same way, we always do things um, hey, we're gon na make sure the battery doesn't die on us, because we're probably gon na have a key on for some time. We're gon na scan it and pull codes out of it and see uh where it's having a problem, it's a little wherever this little chevy and then we're gon na go through and see.

If we can't figure out. Why there's you know, obviously no guarantee we're gon na be able to fix it, but we're gon na give it our best shot and then uh we'll come up with some kind of some kind of something to tell the guy. He probably is a little gun shy. People telling things from the sound of it.

Well, you can see it has. It is littered with codes. Let's go to the report just to see, and i don't know like i said: there's lots of parts and pieces inside. I don't know: what's hooked up and what's not at this point uh, let's see we got a loss of com with transfer case motor, a b circuit, low motor ground circuit, open, encoder circuit male function, lock circuit low.

We just did one with this lock circuit. Remember that that had a bad transfer case control module, um abs, oh motorcycle, okay, they open. This is for the supplemental restraints and body control. What i'm going to do, i'm going to save these just so we have it and then um abc, we'll call it we're going to save it and then i'm going to clear them and we're going to see you know what codes are for rizzo because we don't Know how many people been in here fiddling that leaves us with two and then there were two uh encoder circuit malfunction transfer case lock circuit low.

So that's interesting all right, so we, i think, have some direction. Anyways uh we're going to take them we'll pop right. In here i think before we get super far, what we should do is see what is on the vehicle and what is not because, like i say there is, there is quite a few parts laying inside of here. You know: we've got a transfer case module there.

This is how i receive the vehicle. Buttons are hanging out of the dash here and then, if we go to the back, we've got some other stuff. We've got a drive, shaft uh we've got a transfer case. Motor got your classic wheel, bearing we got the mass airflow.

We got the gas cap, some o2 sensors wow folks, i'm telling you we got some stuff under here, uh anyhow. I guess it's time to start figuring this thing out. What not that thing's pretty well not holding on anymore? Okay, that's why the lock circuits open, hey, yeah yeah, so it's missing the transfer case shift motor, so that makes sense to us why the four wheel drive didn't work um. So i guess first thing.

First, we're gon na have to grab that shift motor out of the vehicle we'll clean out these connectors here, get the mud and dirt and the grit out of them, and then we'll see what uh, when the thunder's going on here. Well, that was easy. So i slipped that baby back in so the transfer case shift motor is back on there. Now i'm going to leave the front drive shaft out for ease of testing all right.

So now, let's see where we're at it's kind of the fine details they leave out when they make the appointment. You know so we'll hop back in here and see what code is in it currently, okay, so we have a 308 motor, a b circuit low, not familiar with that we're going to look that up. Perhaps somebody has yanked the fuse out of it. Also, i don't know um, i don't think we're getting the whole the whole story, but we're gon na figure it out so c0308.

Let's check into that and see what the code set criteria is and see, if it's like say just missing a fuse at this point. So they do have a bolt in actually on this c308 uh, let's see or a pip rather not even a tsb uh four drive inoperative 308 atc fuse open um, and then they write four wheel drive and operative and four wheel. Drive service light will illuminate. Uh diagnosis may reveal that the atc fuse is open, which we don't know yet and if uh c0308 or various u codes may be set, the encoder motor may also be shorted or the transfer straw model may be damaged and they say: uh perform a component check To ensure the encoder motor is not damaged, verify transfer, case control, module control, motor ground integrity refer to applicable schematics for the control, module and quarter motor grounds if the control module and the encoder motor ground are good.

Also check g102 and g107 uh refer the shot manual for the locations and it says - and it says here - and this is kind of key. I think this is good uh. The transfer case schematics will not show grounds 102 and 107. These grounds are various engine, chassis and body grounds.

If then, you know, i thought then well, how does this apply so if 102 and 107 are bad, the transfer case, control module and the encoder motor can be used as a ground path. So that's that's really good. This is good info, usually gm pips and tsbs are kind of worthless, but in this case that's that's good knowledge because you know let's say we went on and we checked the encoder motor ground circuit in a tcm ground circuit and we're like hey. These are good.

It's telling us that this g102 and g107, which are engine and chassis and body grounds if those are bad, the path of ground can likely be through the transfer case, control, module and or the encoder motor. So that's that's good and then there's another one here, uh. Let's see what's this one uh light comes on hard to duplicate 308. I don't think ours is hard to duplicate uh.

Let's see if diagnostics do not lead to correction check all ground support connections if the ground shown in transfer case schematic are clean and tight, also inspect engine grounds and so on and so forth. So this is also, i guess, just kind of stating the same thing. So that's that's pretty interesting. Um we'll have to keep that in our back pocket.

So we're going to continue on our path here. The c308 uh gives us a description. Uh, let's see. What's it say it says, transfer case motor is bi-directional, so it goes both ways.

Uh permanent magnet dc motor when energized through motor control, a or b the ground, is provided to the opposing motor control circuit. So you got two wires power in the ground, or ground into power depends on which way it wants to motor go just flip flops. The circuits and then ground, let's see by posing the opposing motor control circuit, then grounded through the transfer case, shift control module ground circuit. The motor through a series of gears rotates the shaft which moves the mode and range forks to shift.

The transfer case between high auto too high neutral for low, through all the ranges we'll say with the transfer case motors energized, the transfer case shift control module also energizes solenoid for the transfer case lock, which we've done a video on that already. The motor lock is disabled, the locking action is released and free. Turning of the transfer case, motor and sector shaft is allowed. This dtc detects a short to ground in motor control, a or motor control b circuit.

So that's interesting conditions for setting the code. The transfer case shift control, module senses, a low voltage return in motor, a or b when the high voltage is expected. So essentially we could have an open fuse, so i think that's where we need to go first before we check for shorts and all that stuff. We're gon na find us a diagram here.

Let's see what do we want powers grounds transfer case, encoder motor. That sounds good, we'll click on that one and we'll see if we can find out where it gets its power from it's probably going to be one of these big honky tonks up here. So this is motor control, circuit, oops, motor control circuit, a or b, and you can see how it switches from either ground or to 12 volts, depending on which way it needs to turn. We have our lock circuit in there, so we know we're already looking at the right diagram, because you guys probably remember that from the previous chevy we worked on so we're going to be looking at this atc fuse here, auto transfer case 20 ampere.

It's the big one under hood fuse box and then, while we're down there, we will check uh, see that's in the left instrument panel. We don't care about that. I guess so. Let's do that! Let's go! Let's find this little fella right here, atc 20 amp and we'll go from there.

It's probably blown or missing is my guess: oh somebody's been in here uh, let's find the atc she's right there, atc 20 amp right by the rear def. So this one here because yeah rear defogger is a 30 atc is a 20.. We got your 30, we got you 20. The fuse is in it and let's see when's that hot, just like my wife at all times, we're gon na need this little guy.

I guess we better make sure it works boom. It works boom boom. Okay, so we have power on both sides. Does that mean that there's both legs of the fuse? No eric, it doesn't good question, let's grab a kiwi right there and let's have a look at the fuse, make sure the holes not just work out here.

Oh she's got good resistance. I just heard something work down there. Underneath the vehicle come on little fella. You can do it, she looks good in the hole both legs are on the fuse.

I don't see excessive amounts of corrosion up in there and hold it up to the light. Oh, she looks good yep. I just heard the front axle actuator do its thing? Engage engage. We do have power on both sides, so that's good.

I guess we need to keep calm and carry on uh. We need to go and check. We need to check our circuit here on the motor we should have. I don't know we should have power in.

I assume i don't know if both of them in their resting position, if this is true, are they both sitting on ground in their rest position? I don't know um if it has a circuit integrity check. I assume that one of those has power going down it um and then that's what it expects to see on the other side. So let's do something well, let's give this a try. First folks, we're gon na unplug the motor, the motor control circuit.

So that's gon na be uh the four wire connector and it's going to be the red and black. I think black is uh. Motor control, a and b is motor control b, red is b, a is black and then i'm gon na see. I don't know if this is going to work, because i don't know if we're going to meet the right criteria.

I think the engine has to be running foot on the brake and all that stuff, but we're just going to stick a test light across a and b and i'm going to command it on with a scan tool. And i just commanded it on. And i'm not seeing any action there device limits exceeded. It says: okay, so let's go let's you know why? Because look i'm on the transfer case side, we need to go on the harness side.

Awesome first, screw up of the day, not gon na, be my last. So, let's go to a and b on the harness side where something would actually happen if it was gon na happen. Okay, let's try this again. I'm gon na go motor control b.

It tells me to set the parking brake start. The engine hold the brake, put it in neutral, it's in neutral and the key's on, so we're just gon na give it the old couch. Try here i turned it on and you can see it lights up. I'm gon na shut it back off, so that was motor control b.

Let's go to motor control, a tells me the same thing: i'm gon na turn it on and we can see it lights the light, so it appears it appears that we have control. So what i want to know now, because it seems that we can run at least four amps through it, and i think it was only commanding it at 50 percent. That light didn't seem crazy, bright to me uh, but in either case it was several amps. So before we get too involved with that, let's see do we have do we have continuity across this motor.

You know: do we just have a bad transfer case motor? I don't know what the resistance value will be. It's probably gon na depend on where it's sitting on the where the brushes are sitting, but it should have continuity across it right. Let's see what we have according to the ohm meter 2.4 ohms, which i guess that's plausible, so 2.4 ohms, so why? Why is it indicating that the circuit is no good when it appears to function? Is this a product of a bad transfer case module, whoa, hey, everybody needs to kind of calm down there. We can see that sucker moved and i think it blew a fuse.

We didn't have it commanded on anymore, i'm gon na pop back into the scan tool here and see. If we can uh see what happened i'll, tell you what happened. Is we blew a fuse? I heard it snap, i'm positive as soon as i plugged that thing in i heard it pop yeah see it didn't even find the transfer case control module that time. So, let's change that fuse and find out what the thunder happened there shouldn't have been any power applied to transfer case shift motor, a or b.

So it's interesting that it that it blew the fuse. Let's see that's what happened. Yes, sir she's open. So that's curious.

Okay, it didn't blow. I did hear the lock on the transfer case. I'll do its thing: let's set that to the side right there and then let's move the coffee uh, not a sponsor, let's re-read, let's clear our codes and then it will re-read them clear codes. Yes, it's not clear now, let's back back out here, all right, let's clear out our codes, okay and it's still indicating a motor a b circuit fault, which is really bizarre - is that motor? Well here i got an idea: can we do this um? Can we shift it? Let's see we can control circuit a and b, which is no good because it doesn't disengage the lock.

So that's not helpful um. This doesn't allow us to pick. It doesn't allow us to pick which gear we wanted in uh see that's the mode switch. Is that going to allow us to shift too high to four high? It does but nothing's happening down there.

Okay, front axle is unlocked, it's not requested, which is weird because we're requesting four high, perhaps transfer case lock, enabled for low all-wheel drive. Perhaps none of this is functioning simply because we have that circuit code. Let's do this, so here's what i did you can see. I have two test lights hanging, one because in that connector there's four wires: two of the wires control, the transfer case lock going to inhibit the movement of anything and then we've already established the other two wires for the transfer case motor control.

I want to know one thing is: if, when i command motor a and b to move, does it disengage to lock well it's first of all, let's make sure we have okay, so we have a good lock signal, so our 194 bulb. There is the one indicating when i'm commanding unlock the transfer case, so we know that circuit works and then we already know transfer case control a and b both work. But let's see if it lights up both of them. Let's see if it unlocks it and then tries to move it because that's going to be critical to know so we'll try to move it, i'm going to turn the transfer case lock or the motor on.

Oh it does it unlocks it. Then it moves the motor. So that's interesting quit moving it. It still has it unlocked.

I turn it off back back out and then then it relocks it. So let's go to transfer case motor b, so this is going to move it in the opposite direction. Hit okay. So we should see if it does the same thing again, it's going to unlock it and then move the motor and that that's the the proper process unlock moves.

The motor gets all the way to its end. It's looking for certain inputs, it's not seeing them. It doesn't know what to do it disables everything and then turns the lock back on okay. So i'm curious with our load, substituting our you know: substituted load, i'm going to clear the codes out of it and see if it comes up with the fault.

I don't know what it's: if this substituted load will be good or not, and apparently it is because i just cleared the codes, and now we have no fault now, theoretically speaking, if we remove our substituted load for the motor, this is our transfer case motor and Then we come back and we re-read the codes. We should have a code for that motor. Why don't? We have a code for the motor that is ridiculous? Okay, maybe because it's it's detecting a complete short to ground through that motor. Let me plug that back in folks.

Well, i tell you what, before we do, let's unplug the lock, let's see if it throws a code for the lock, it should throw the code for the lock back back out of there go back to trouble codes. We should have a lock code transfer case, lock circuit low, okay, so must be the the 2.8 ohms or whatever it was that we had in this motor circuit is too low and unacceptable because it likes the substituted load of our 4 amp light. But it does not like that transfer case motor, which must be too low. So we don't have a known good value and usually you don't have values on you know dc brush type motors because they're ever changing.

So let's plug that back in. Let's put it back and we'll clear the code see if we have our motor fault, no communication, so as soon as i plugged it in it blows the fuse, that's pretty peculiar, let's see if it did below this fuse. I don't know if you can see inside of these ones. Yes, sir, so i'm gon na stick another fuse in there just heard the front axle disengage.

Now some people are asking you know how come i haven't gone through and checked the ground. Yet uh a bad ground can't blow a fuse uh, regardless of what the internet tells you. A bad ground creates an open circuit. Open circuit creates low current.

It takes high current to blow a fuse, so a short to ground will blow a fuse, and i'm assuming internally in that motor. It is shorted and drawing way too much current, so just ohm checking across the motor again and we're down to 0.5 ohms. Okay. What i want to know is so these wires go directly to you know to the transfer case shift motor, so they come around in that loom and then right into the motor, and that's where the lock control circuit is also so we're going to leave.

One of these hooked up we're going to unhook one of these we're going to clamp it into this baby to see if we have a short right to the transfer case motor. So we'll go right to ground and it did say in service data that there is a capacitor in the motor and that we have to leave it hooked for 10 seconds to get a true reading. But we can see that that that leg of the circuit is direct shorted to ground. Okay, that's one half of the uh, the motor circuit.

Has you know if we apply power to it, it's just going to go up in smoke because clearly you know 0.3 ohms. I guess we could check the other leg, which is going to be the same thing, so let's unhook this side and then walk up this side. Let's see what that one says, point three ohm. So it stands the reason why this thing blows a fuse.

I hate this meter why they can't leave the back lighting on owie you, son of a mother, how many times you gon na hit your head on that fella uh. I don't have any other answer for you folks. This this transfer case shift motor is junk and we need a new one. Ah, this puts me in a pekko.

I just looked it up uh. The only one i can get today is either a remand junker from napa or a doorman from fast freddies down the street. I don't like either choice. The one from gm is 640.

Some bucks i almost would rather have one from the junkyard than then either use a re man or a dorman. I'd rather have a junk one um. So maybe i see i was just looking here at the uh parts guys i see it fits 98 to o2 or 0102 silverado, so it's a pretty short year, but down there the wilbert jupo of the bath, who doesn't sponsor us. I know they got a lot of these old chevys and i'm just thinking.

I know it's a gamble, getting a used one, but i'd almost rather have used oem than new, dormant or reef. You know rebuilt uh, because obviously that's what we already have. We already have a remand, that's already junk and i don't want to be the a-hole to put one on and then you know two weeks later, guy takes it and things broke again. So i think we might go that route.

I've made the executive decision we're on our way to wilbert's you pull the bath, not a sponsor. It is a decent day out 63 sunshine and 50 mile an hour winds. So that's two-wheel drive. Here's a 4x4.

What year is this one? The 2000? I think that's compatible negative ghost rider that one that's got ta, be at least that's, probably not five. I like to find one: it's not completely freaking rotted is it denali. I may have came ill prepared folks. I did not so this thing's never been out, which is great, because it's an oem, ah the one bolt i had to wrench out when it hits the drive shaft.

I don't know if we're gon na have enough enough room here. Let me fiddle with this. For a minute it is windy, it's windy and uh. We did get one of the chevrolet now this thing only fits a few years, so unfortunately i did walk through all the rows of the chevys and none of them.

I didn't find anything out there. That was mint. Let's put it that way. Uh almost everything was rotted right in half but, like i said this, one does have a uh, oh yeah motor on it appears to so i got that off, couldn't really record it uh.

I was embarrassed. I didn't bring enough stuff to get the driveshaft out, didn't bring anything take drives, yet that one i forgot was in the way, so a little bit of finagling, a few uh swear words and boom out. She comes so hopefully this one that we have is good, or at least better than the riemann or the dormant, at any rate, which i think it will be providing it works and then we'll go from there and uh. You know see if we need to do any more diagnosing but kind of bizarre.

You know we're back hello back from the club. See uh-huh. Did you even see my wristband wow, the club i had my hula hoop got. Some glow sticks what you cooking! What's up? That's it.

I don't remember now, if you remember, come, find us we'll be fixing stuff. I got some of the schmoo off this, the white uh crusty stuff, and i figure before because i figured we'd better, find the wires to look for before we even stick. This little guy in let's find out if it is shorted to itself, so i hooked both of these up to the motor circuit. So it should be.

You know whatever it's going to read across the brushes and stuff should be pretty low, so this one is 1.4 ohms, ohm and a half. But more importantly, we want to find out if it's shorted to the case, like the other one was so stick that on there and technically it shouldn't be - and this says oh uh - let's see yes, sir, make sure i got this going right and then we're gon Na check the other side - and it also says oh over the limit - let's just make sure we do have a good. We do have good continuity here, let's make sure yeah. We do so case decay.

I just want to make sure my connection was good. So that's good, so technically this one should work at least that portion of it. We don't know if the rest of the rest of it could be junk, but we should at least resolve our motor code. Let's make sure our lock circuit here is intact.

That should have you know, maybe 10 or 15 or 20 ohms or 19.5. So that tells me that the lock circuits has connection. So i'm going to take and stick this little guy on, like i say, she's, not mint, but it should be better than what we have and should give us some results. Here's! Oh that's my receipt! Where's! The list.

We had a list, there's quite a list of stuff. They had that this thing fit like winning the lotto. When you go there, that's all the vehicles they had, but uh, o2. 2002, basically silverados avalanches, suburban, some 99, some 03 jimmies um 98k 1500.

But whatever we got us a gasket, let me pop that on there uh where's our scan tool. Ah crap, i found it. We left it up here. So let's open this back up yeah.

It will set it down here and we'll go back in here. Let's see what we have for codes, we're going to clear them out, probably so, let's clear them out unless this this motor, we might have just wasted our time nope, we didn't just waste our time, awesome, so no more coats. So let's do this. I think technically, our button should be lit up now, right, all right, no more service we'll drive this baby lit up.

Oh, she is she's in four low. I don't know if i got my foot on the brake nope, we don't too high fancy. Look at that piece of junk corn from the junkyard works better than the new one. I think we're done folks uh well probably ought to put some of this crap back together.

I guess anyhow, i can't leave you guys hanging. Let's take it for a rip. I didn't put the dash back there. I did put the drive shaft in it because we need one of those to check the function of this did check the grounds.

The g107 is simply the ground strap under the hood. The g102 is that mother lover that lives on the left side of the engine block. You know the one that when it doesn't work, the car doesn't run that one all right. Let's go down to the south main auto four-wheel drive test facility, see how things function.

She's uh got a lot of miles on her uh two and a quarter. A lot for chevrolet whoa no brakes there. We go. Abs got some unwanted abs, activation, you're, classic wheel, speed sensor dropout from general motors since 1997..

We've made sure you coast through every stop. Sign someday they'll get it right, maybe when they met the electric car. Oh great, we can't go to our regular test facility because the town's there they're fixing up the ballpark. So we better not go there and be jerks.

Let's go to our other test facility. We'll use this four-wheel drive test facility right here, we'll go out here where nobody can see us out on the slippery grass all right. So, let's see so we're in two wheel peel right now, let's give her some beans - oh yeah, oh she's, ripping some rooster tails. Four high give it the whole shot.

Oh she's hooking now boys all right back in two-wheel drive she shifts into the neutral into the four low, we'll give her a four low hole shot. You ready chevy thunder yeah all right a little more excited than i should have all right back into the neutral back into the four high, hopefully she's, making a shift back into the two high all right. Let's uh turn this beast around, give me 48 and i'll turn. This rig ring better, not fall out there.

It could be a little saucy all right. Let's see, i tell you what let's see we're at two-wheel drive ready. Oh i'm stuck! I can't go. What do i do boom put it in for auto? Oh she's, hooking.

Now, oh yeah, all right there we go uh. I don't know what else to do other than just drive it. There's our previous burnout sick. I guess we could flex it up on this dirt.

Pile get out of here before the cops show up. I don't think the cops will show up but anywho. I guess we just need to just give it back to the guy and see what happens uh if it works, it works they broke down. Are they nope? It doesn't look like they got a flat tire.

We could stop and help them if they did they're just taking a smoke break or something we'll leave it at that. Folks, there's your bonus footage enjoy it there's nothing more. We can do you.