Hey there viewers and welcome back to the self. Main Auto Channel We got the 2009 Jeep Grand Cherokee It's got the Big 37 Uh. Customer complaint on this one is the tachometer and speedometer drop out where you're driving and they drop out more like a glitch. They just pop down and pop back up.

Pop down, pop back up. Uh no, they're not tying. They don't do it at the same time every time. It's just really random when it does it and it does it quite often now.

I Drove, it started up, just went around the block and it did it. And just sitting here at a night all the tachometer drops out. Uh, quite a few codes in it. Now the customer has gone ahead and Uh has replaced the instrument cluster for other reasons.

I Guess other gauges had quit on the original one or something and he replaced it and this replacement one still does it and he went so far as getting another one and that one still does it. so it's likely not in the cluster now. I Did read the codes out of it and it has several codes in it. has engine codes for you know, catalyst efficiency and you know some other issues there that don't really pertain to this.

and there's codes in other modules that I don't really think pertain to it. but there is a code that I think does pertain to it. and uh, this uh car has two Uh data networks on it, the Can C and the Can B they call it and it appears that the can be like Bravo is not functioning as it should and I believe that the tachometer and odometer are a bust. input uh to the cluster and when that uh data bus has going wonky per se, that's when this happens now.

I can show you what it's doing and I'll show you kind of where I'm at I haven't gone much further cuz I wanted to bring you guys along. Uh, it may be interesting I may not be able to find the problem, but we might and I want to have the camera on if we do so it can benefit somebody else. So first of all, I'll show you uh, what it does here. He left a spare clusters in there and then brought a a fuse box.

Uh, for some reason I'm not sure what uh uh, we might might need. it might not I'm not sure. Let's just go ahead and start it and it. yeah.

I was going to say usually it does it pretty quick so that's what it does and it doesn't matter what RPM it's at it, it still does that and when you're driving, the speedometer drops out at the same time. Uh, none of the other gauges do. Nothing else in here really seems to go haywire when it's doing it. That's the only thing that you can observe you know inside the car so let's see.

see that. So I'll shut that back off. I'll show you the codes that I've obtained and we're just going to do it like this. We're just going to do some screen pointing because it's a little bit easier.

uh did a full system scan uh this is the Can C uh which has the engine controller, airbag, ABS transmission um wireless control module and then over here on the the Canc we have driver's door module, overhead module, amplifier, passenger door, sunroof, and instrument cluster. So I'm going to go to the report here. show you what codes are in it like I say engine controller These you know these are just problems the car has but not this problem. Uh, Trainy has a stored code I haven't cleared any codes out of it but this is where I started uh kind of focusing my efforts I think uh Central Gateway uh or the front control module I think they call it can be bus code uh 019 can be minus circuit low or 25 uh passenger door module has a code set against it amplifier driver's door module uh a stored code here in the wireless module sunroof modules on the can B this electronic overhead modules on the can B and you can see we have Um codes related to this Now this lost com with heated seat control module.

that's because I have it unplugged currently and I'll show you why. Um, actually let me show you something else here. First thinking that we're going to focus our efforts on the the Can B data bus I went ahead and I printed myself out a diagram of the entire Data Network on the car so the Can C and the Canb so it's two pages and then I printed out a a simplified version: uh from service data of those two data networks, here's the front control module or the Central Gateway. So both data networks run into the Central Gateway and then they talk to uh, or you're able to talk to these networks uh through this diagnostic cus, uh, the diagnostic can Cbus from the data link connector.

So with Chryslers you can't go right to the data link connector and measure. you know what's going on on the data. Network So if we come over here to the C and B bus now, this is way outside my wheelhouse folks, just I'm not the best at explaining this, but I Looked at all the potential modules that this vehicle has and I've highlighted the ones that it actually has I Got that information a from looking at the car and B I went into the Uh Central Gateway and looked at the configuration information to see what it was programmed for. and then I just went through and highlighted each one of these modules it has.

So it has eight modules on this car: the instrument cluster, the amp, that overhead module, passenger and driver door module sunroof uh HSM I don't remember radio uh, heated seat module sorry yeah, had to think for a minute and so I've seen that I Think we have a problem on the Canb bus and I've gone ahead and hooked up the Pico But in order to talk to that bus because we can't do it at the data link connector, we have to tap into it somewhere. The heated seat module lives under the passenger your seat as supp as I could show you. but you could also believe me. so the heated seat module lives under here.

I've simply unplugged it and probed into the Can high and Can Low and ran the wires out here to our Pico so we could have a look to see what the data looks like on this module. Embarrassingly I don't know what it's supposed to be I assumed it was going to be like regular. Can you know um one and 1/2 to 2 and 1/2 volts on High and um 2 and 1/2 to 1 and 1/2 on low or something along those lines. but this one appears on Can High.

Currently it's running so the blue Trace is Can high. It's running from 0 to 4 volts now. Can Low doesn't look the same that appears to be running from 5 volts to 1 volt. so they both have a Delta of 4 volts typically on Can.

From what little I do know about it is, it usually creates a mirr image of it of itself. so let me uh change the speed here on our scope and this is how uh you know these modules uh communicate sends these data packets of of ones and zeros and has certain priority and identifiers and stuff like that which I guess we won't get into too heavy because I'm not the best at explaining it but what I am good at is seeing an anomaly. So Can High appears to be working but Can Low certainly is not a mere image, but it is. Sometimes sometimes it appears to function and we'll see certain data packets that appear to you know mere image.

you know can high and can low but there's also uh times when it doesn't and they kind of come and correspond with when the module's dropping in and out. The other thing I observed, if we go back here, we'll pick a control unit like the instrument cluster per se. When we go in here I Noticed that live data was also coming and going. let's see if we can.

uh yeah so it'll drop it'll you know not available. Then the data pits come back and it kind of goes through this cycle. I think as it's looking for these data pits whereas they're being transmitted and then they kind of come and go. um you know and I was I Was noticing that seem to be a little worse when the car is running.

but I did notice that the data stream seem to be coming and going so on a Cher like if we go in there and shut the key off, these instantly all say na, you know, not available So I'm assuming uh that it's looking for or it's you know interpreting the transmission per se and it's losing them, then it's getting them, that's losing them and getting them and that kind of corresponds with you know what we're seeing over here when we're looking at the actual data. Hope it all makes sense. So long story short, that's where I'm at with it I Got there, had to go to my dentist appointment. got back.

it's after hours but I kind of want to look into it to see if I can't figure out what's going wrong. Um, this is what my gut tells me. My gut tells me that we probably have a module going wonky if we had an open circuit. I don't I don't think we would see what we're seeing if.

uh, if we had a short short to power short to ground I Don't think we would see intermittent good data transmission I Think we perhaps have a module that's going wonky and you know all bets are off and it's doing what it's doing now I could be wrong. Uh, the best way to figure this out would be to start breaking the circuit down. but Chrysler unfortunately uses you know, like this trunk style design where we have um we have our front control module here. we have the data lines coming out and then all the other modules are just teed into it like like a tree trunk.

like this is a trunk and then these are the branches and they just all come off from this. and the other thing that's kind of unfortunate about Chrysler is they don't really seem to have any connectors. Everything's held together with splices. You know these wires literally come out and they go to splice packs and they're just, you know.

Branch Off to all these different modules. Uh, my thought is is to use some logic. where are these modules located? Can we get to them? Can we unplug them? and which one should we start with? Um I was shooting from the hip when I went to the uh heated seat module cuz it's an 09. it's a New York vehicle.

It sees salt. That module's mounted on the floor and it's under the seat. So I say well. we got to tie into the network.

so let's unplug that. We'll tap into it there and maybe we'll get lucky and it's all crusty. It's not I unplugged it. You see what we have I'm just probed into that connector.

It's not that module. Uh, what I'd like to do is identify where these other modules are uh and what one's easy to get to. Um one I'm thinking of is this amplifier module. You know, let's see where that lives somewhere is in the back of the vehicle.

Is it on the floor? Is it likely to be? You know, living in a pool of water, stuff like that. and if we can't get to them and they're not easy to get to. my next thing that I would like to try is to remove power from a module. uh by simply pulling a fuse.

That is uh a sometimes but not always case. Um, it's nothing I've experienced uh personally. but I've seen videos uh on YouTube where they uh, a person has had a module going corrupt. it's very difficult to get to and I think the last one I saw Bernie Thompson did one.

it was on a airbag module. you know, got tear the whole stinking car apart to get to it. He did. He tore it apart, it was corroded, you know, whatever and you know, unplugged it, restored.

uh Data Network But he also demonstrated in that video the sometimes but not always situation where you remove the fuse, remove power from that module and sometimes it'll clean up. Uh, you know the Can Network so we're going to try that and if it doesn't work, you know we still may have to get to these modules to unplug them. That's the best thing I can think of. that's the best place I can think to start.

So let's get started. I looked on uh the component Ator to see where things live I looked up the amplifier module and it says left rear, uh left rear compartment and then it showed a wiring uh, harness. Kind of coming back here. So I think what we'll do is, we'll move some of this stuff here.

standard, not even a metric one and all kind of stuff in there. we'll just uh see if shove some things back I put this stuff on the floor. we'll do some uh oh okay yeah, this thing lifts up here. I don't know if this, if this floor comes up, if it's under.

oh that's interesting. This is all wet. This is soaked so there's water dripping off of this. um well I wonder.

Well, that really got me wondering now. Um I don't know how the rest of this come I don't I don't know if we take off this threshold. If we can see well, we can maybe at least have a look under under here I might have to look on a component locator again to see I Thought it looked like in that diagram that there may have been a a well here and it was somewhere in this vicinity. Um I Don't see much like the padding down here, so may maybe it just got wet inside of there.

Maybe that's just a a bit of a red hearring? Um, let's leave this offer right now and perhaps go. We'll default back to seeing where the power comes from that amplifier and see if we can just yank the fuse for it. Uh, before we put this together in case in case we have to unbolt some of this to find out where I may be barking up the wrong tree here. But let's go try that.

So I just did some looking. It is. uh, the wiring diagram led me astray. It's in the left rear quarter panel, not not down under.

So uh, we're We're going to go with our rout of finding the power source for it. It's supposed to be fuse one inside fuse box 30 amp. Oh, when the car was delivered, it was delivered like this tour apartment. So I not do any of that.

Let me set you down and find the fuse here. Well, there's only one 30 amp fuse here up in the corner. see if we can reach it like I Say this is a sometimes, but not always. But we're going to try it because it's the easiest thing to do All right.

So there is our 30 amp fuse. Let's look at the can bust now. All right, that's still screwy and theoretically we should have lost communication with the amplifier. Let's just be sure make sure we got the right fuse.

Yep, Okay, so we lost communication with that. so we did. We did get the correct fuse anyways. I think next thing on the list, we've got the two door modules they're difficult to get to I Looked at a power distribution diagram and it shows circuit breaker number 32.

This is in the left side junction box so same spot we were in and it shows it running both door modules. So kind of two birds, one stone driver door module, passenger door module. so let's go yank that one out and see if there's a change. There's two circuit breakers that live in here I don't know which one's which so when all else fails, yank them both out.

That's what the circuit breakers look like. so we'll take that one and we'll take that one the right side by side in there. Let's go make sure the mod Mod's dead. No change in our data communication.

Let's see here. Um, yeah. Driver Door module: Let's see, we shouldn't be able to communicate with it. Oh no, Can we? Interesting? We can get it? We can.

Let's just check: Passad Door Module: I Assume those were the right circuit breakers I may actually have to look now. yeah, looks like we can still talk to him. Interesting. Okay, you know.

I Just got thinking: I Don't think the circuit I think the circuit breaker is a circuit I Don't think it's the only circuit I Think that's probably just supplies power of the window driver door module. Here we go. Yep, it's a different fuse. Yeah, that that's the only thing that makes sense.

I Didn't think about that. They can't have it running the circuit breaker is only for the power window circuit in that in that circuit. Uh, Fuse 12 10 amp. Let me write this down.

Yeah, all right. I'm going to put those circuit break well I Guess we can leave them out. Number 12 I Think these are labeled. Let me get my face down there.

In good engineering fashion, they are labeled F1 right through F25. However, the bracketry that holds this in covers up the labels. This is circuit Breaker 3 for anybody who's curious. Uh, the guy had the spare fuse box here from the junkyard.

so I just looked at this. So Fuse 12 uh, row down, second one in and it Powers both door modules, passenger and and a bunch of vanity lights. So we're going to leave that out I'll leave those circuit breakers out. Let's go see if there's any, uh difference here, folks.

I'm really hopeful. but I can tell no change there. and then we should have lost communication here y we did because it would have been talking by now. All right, let's make notes down here that we've removed fuse.

Yeah, so no communication and then fuse Number 12. It was for both of them and we pulled fuse. If I don't leave myself notes I'll never remember. Sunroof is fuse number two.

We'll go pull that. that's a 15 amp. You know what? Let me look 30 I haven't put any these back. I Probably should keep track of everything here.

That's a 15 amp for the sunroof. Let's go have a look. No change here. Let's make sure we lost it here.

Have to go back to the sunroof module. Oh, it's going to take in a minute cuz it's going to have. Oh no it didn't. Let's go in here and this should be dead.

Yep, okay, that one's dead. The overhead module should be out here. One of these. I'm going to figure out which.

uh, which one it is. Let me to go double check. Uh, both of these fuses. the 15 and 20 amp.

one is for the electronic overhead module and oddly enough, the other one is for the radio. Um, they're not labeled on here number. they're actually labeled as spare. Uh, so we yank them up.

No change there. Yeah, and the electronic overhead module is dead and the radio should also be dead if we try to talk to this and that's also dead. Interesting. So we pulled the fuse.

I put the other fuses back in I I Don't think it's going to screw us out of anything and then the uh overhead module pull the fuse. Feel real silly if it's in freaking cluster. that's the only thing we haven't killed yet. was the cluster and then the Gateway which I'm not sure how we'll go about that.

Okay, but like I say by pulling the fuses, it's it's not a a tried andr uh method here. Um, it's hopeful. but let's uh I think we can probably just unplug that. Well I didn't bore you with it, but it made no change.

Uh, let's see so I'll just make it. note here: we unplugged. there's two plugs on I unplugged the one we lost Comm with it and I think I had the com wires on it from what I could see. Uh, let me think here folks.

so this is our integrated power module and then this is the front control module and it and it bolts to it. So it has a it has a connector here where this this module separates and bolts to it. um I looked down a diagram and and there's uh, the connectors here in the actual front control module and they one of the connectors houses all of the canned data bus. it goes in here and then you know this acting as the Gateway that goes to the data link connector.

um I observed when I picked it up that these I was coming in here to try and pick these red tabs out. went to get my glasses and come back and I'm like oh well, these Ts are already out So I don't know if somebody had been here before, but uh I'm just looking at the computer over there. everything looks normal there e oh well, look at the connector you idiot. I was going to say I looked at the screen over there, and it's fixed.

but we got green. We got green baby. It's always the last freaking component, isn't it? See? Can you guys see that? Get it up here. more towards the middle.

we got green crusty on a pin there and obviously it's a pin that's doing something. because let's go look at the uh, let's go look at our computer and look at that. So evidently the Can high is supposed to be from 0 to 4 volts. at least that's how it's function in here and Can low is from 5 Vols to 1 volt.

but that's what it should look like. a mere image of itself. I Think they do it for redundancy. I Could be wrong, but there there's our.

There's our Data Network It appears to be restored and you know what that is. Our white and white with orange. Let me set you back down. White and white with orange is our Data Network wires.

I Thought they were going to be in this smaller connector. Perhaps they are, but on this one here, we'll have to. We'll have to get a diagram now. I've got a white with orange right next to a white, which is likely the network wires.

It's the third pin in. The third pin in here is the one that has the case of the Crusty Is the PIN rotted off? Oh e it gets uglier. Yeah, the pin's completely rotted off and there's pus coming out of the module. Fancy.

Let me, uh, give you a little what's up, let's see if we can enhance Enhance so that PIN in is completely gone and that's our canned low wire there. but we got crusties coming out of that and we've got some crusties coming out of that one. Oh, that's interesting. So we're going to need a front control module for certain and we're going to need at least a pin and or this connector because that pin has broke off in there.

Yikes. This connector, however I think is likely salvageable. You know we'll clean it out with some deox I bet I see it's got a new Wilbert you pull it a bath, not a sponsor battery. I wonder this is like from you know off gasing of the battery that you know thing's kind of in a cruddy spot where it sits down there.

I'm just glad we came back and found it. I Was going to go home after my dentist appointment because it was at 4:30 and I said you can't go home Eric you'll never be able to sleep and I'd be down here at 4:00 in the morning or sometime when I gave this some thought I wanted to come down and try some stuff. We're going to have to see how this connector comes apart. I'm going to definitely have to get out my spectacles for that looks like the back half snaps off it that holds the wires here? Yes sir.

and it does. Yeah, so that slides off boy with a lot of wires here, young fella. So that's going to slide down them wires keeping them all separate going. Have to kind of straighten some of this out.

We'll work that side of the connector down the the inside here has to be able to pop apart and then hopefully we can depin it because it would be silly to try to replace the entire connector. Awful lot of wires here. Get that tape opened up there? Well, that was fun. Saved us a lot of ripping and tearing.

I Don't think there's any way to really deow the front control module. Perhaps there is, uh, perhaps I can look on a wiring diagram and see if that is plausible. we can try that method. I've kind of kept that method in my back pocket since seeing it.

Uh, seeing. Bernie Do it there. That guy is super sharp. If you really want to feel like an idiot, go watch some of his videos.

Bernie Thompson Brilliant, brilliant man. Okay, well let me fiddle with this. see how this comes apart, see if we can't depin it and then it's going to. We're going to have to wait till tomorrow.

uh to see about uh, getting parts. I'm going to have to do some research I don't know if we can put a put a Ed module in I'll check price and availability on a new one. Of course, as far as the pin goes, might be taking a trip to Wilbert you pulled to B Uh, but let's see I guess we'll uh we'll wait till tomorrow. let me work on this.

Maybe I'll see if uh I can get that apart for you. Get a hold of the wire here. Okay, the pin is wiggly there it is. Old son, there is our broken pin.

Well, it's funny cuz that uh, the female half here, if you can use that word in 2024 appears to be in pretty good shape. Seeing if there's any way to come in from the back side and push that pin out. Ah, it reminds you of your mom getting a sliver out of your finger when you're the kid. Go get me the sewing kit, sweetie.

That's not what my mom sound like. Let me see if I can get a hold of that sucker or Vanessa for that matter. Manessa likes to get slivers out of my fingers, but I think she gets too much enjoyment from it. To be honest with you, the needle goes a lot deeper than I think it has to typically.

Oh I pushed it down in. Oh, got a spider got him just seeing if tapping it will get it to perhaps flick back out of there now. I get to let me fiddle around here folks. Let me show you.

hopefully I Don't drop it I already dropped it once I Had to go find it. So there it is. I Don't know if that's going to be able to see that, but that is the male half of that pin right there. I was able to get it out.

little bit of fiddling I got it out and then I dropped it down by the battery. but I was able to see it and decipher between that and a speck of dust. And I think you know looking at this terminal here, enhance and hence hope so you guys can see it there. Of course you can't you're looking at my corroded thumb.

I've got the corresponding male half here. the AES wave kit. Oh yeah, we still got pin tension baby. Yeah, that terminal is still good.

It's still good. Stick it in the empty hole here. We'll use it to clean off some of this corrosion. We we'll clean out this whole connector.

but I think we're in good shape. Yeah, the connector feels great. Let's slide it back up in the cavity in which it belongs. Number three: Make sure it still locks in.

and it does. We'll clean off that dab of corrosion there with some deoxit. I'll put the connector back together here. Okay, snap that back together because we don't want it falling apart.

We'll run this back up. well. This will be good at least now. We just need to get a front control module and we caught it before it became a big huge mess.

so that's a plus. Okay, so that's all snapped back together. Let me get some deoxit and uh, spray that on there. We'll kind of get them cleaned up of course once we put it back together.

well, let's see if we click that back on there. I'm curious if it's getting interference from something else. Yep, so as soon as I plug that back in the data network over there goes stupid. Oh, you guys can't see anything so it's more than more than what meets the eye.

There must be corrosion up inside the module making it do funny business. All right, let's clean these babies up. This is the stuff. I Like to use: deoxit D5 D series seems to work pretty good.

melts away corrosion. They have some other cleaners that are specific for like gold connectors and stuff of that nature. This stuff seems to work pretty good. removes oxidation, improves connection seals, protect surfaces not a sponsor I buy it myself.

So at this point folks I just set the uh front control module and integrated power module back. uh, back on there. I'm going to see about potentially getting a new one and if we can't get a new one, we're going to have to try to find a used one. uh with with the same configuration I Don't know, you know I know if this was a tipm you know we'd be able to do a configuration restore uh using the Y and we could uh, you know, just flash it to what the vehicle is built by VIN I'm going to have to do some research if we can't get a new one, if we can get a used one and you know are we able to put it in and can we change any of the configuration settings in there if we have to.

So I'm going to do my research on that. I've gone ahead and unplugged the Pico from the heated seat module uh and got this so we can start it and drive it outside where we're waiting for parts. I've gone ahead and cleared all the codes out that we created. uh, these are the codes that are left.

Looks like everything's talking but everything's going to be unhappy. So Gateway has you know our Can B bus our Can bus low circuit low. uh indeed it is because it's completely unplugged or you know, removed cuz that pin's bad. Um, the amplifier has a can be code stored in it can be minus circuit ECU in single wire mode so that's kind of an interesting code.

I did look into that uh on the heated seat module um just cuz I wanted to see how it defined it and uh, it's just kind of a strategy it has so that's kind of neat. So yeah, we just have the Can B bus faults and of course you know we had the codes in the ECM which those are going to come back as soon as the guy drives it but I guess that's a different problem for a different day. so that's that folks. We're going to leave this one uh, potentially is a part one.

uh I don't know how quickly I'll be able to obtain what we need to actually repair this properly, but hopefully this video in and of itself is useful to somebody. Um, as far as tracking down the problem now, I Did look on a wiring diagram to see if there was a fuse or fuses that run that front control module and there was a there's a host of fuses so we can't really. Unfortunately with that style module, we can't. you know, try the old pull the fuse trick and see if it takes care of it.

I Would be curious if it does, but with the corrosion in the connector or you know, up in the male half of that connector in the front control module I Suspect pulling the fuse out of it probably wouldn't fix our issue. it's hard to say it's all speculation until we get an example that we can actually show you and and learn on. Uh, Fortunately for us, our problem was right here. It was easy to get to and uh, not too terrible to figure out.

Uh, my process for figuring out was simply as you guys saw, You know it's doing some logic, seeing how the system's built, seeing what it's seeing, and then coming up with a plan. Uh, if that module there looked good like for example, if we got there and it was clean and unplugging, it did nothing at that point. I'm going to have to actually physically track down the physical modules and start breaking down the system by unplugging them and that's that's that would have been my next step, but we didn't have to get there. so you guys want to get there in that comments section.

questions Comments: The insty the Facebook Be on a lookout for part two of this video at some point in time may not come out right after this one, but if I fix it, be sure. Uh, you be sure you rest assured that I'll post it on the on the Facebook on the YouTube. You guys know and just remember viewers. If I can do it, you can do it.

Thanks for watching.