May 29

2009 Acura MDX Heater AC Issue



Mark: 2009 Acura MDX with a heater issue. Hi, it's Mark from Remarkable Speaking. I'm here with Bernie Pawlik, Pawlik Automotive in Vancouver. 24 times they've won best in Vancouver as voted by their customers, and we're talking cars. How you doing, Bernie? 

Bernie: Doing very well. 

Mark: So as I mentioned this Acura 2009 vintage had a heater issue. What was going on with this car? 

Bernie: The mode operation of the heater wasn't working. So the mode basically controls where the heating system or air conditioning system blows the air. Whether it's gonna blow it on the defroster or in your face or on the floor or all of the above. There's basically a motor and a door and a flap that operates that system. So that wasn't working on this vehicle. And that's why the car came to us. One of the reasons it came to us. 

Mark: So, okay. That sounds like you, how do you find out what the heck's going on with that? What testing and diagnosis do you do? 

Bernie: Well, first thing we did was plug a scan tool into the vehicle because these are electronically controlled, long gone are the days where these doors were controlled by cables. I dunno if that's a good thing or not. I think from an operational standpoint, it's nice you don't have the cable, but from a repair standpoint, it makes it more complicated and expensive.

But anyway, so we plug a scan tool into the vehicle and then we can diagnose the heating AC system of the vehicle. There's a module for that and there was a trouble code for an open or short circuit in the mode door or the mode operating motor. So that was the first place to go. A few more tests were done and we determined that the mode motor was defective. 

Mark: As hard as that is to say, was it a difficult job to fix that? 

Bernie: It wasn't really too difficult. So I think we've done podcasts on these on different vehicles, but in this particular car, and so on the heating system on most vehicles they use these motors, pretty well every vehicle, they'll use these motors. Some of them will have maybe three of them, some might have five or six, depending on the complexity of the heating system. If it's a split type of heating system they'll add more. I say by split, you can control the temperature on either side of the vehicle.

So some of these motors are easy to access, some of 'em are difficult and require removing the whole dash of the vehicle. This motor was not one of those fortunately, it wasn't too difficult to take out. It could be accessed from under the dash, removing a few components and items. So not too bad of a job considering how these things go, because we do have somewhere you have to pull the whole dash and heating box out. So, not so pleasant, for us and for the customer's wallet. 

Mark: No. And how do these motors work? 

Bernie: Well, I've got some kind of cool pictures. I say cool because it's kinda interesting. You can actually take this motor apart quite easily. So there's our car.

2009 Acura MDX Heater AC Issue

 So this is the actual motor here. Now they're all slightly different. But this is one view of the motor. So I'm moving my mouse pointer around. The electrical connector goes on here. So there's a door inside the heating box and this attaches to the door in the heating box.

2009 Acura MDX Heater AC Issue

Every once in a while, something will go wrong with the door too, which is much more involved repair than changing the motor. But anyways, that's not too common of a problem. Usually the motors go bad. Inside here, there's, there are gears and there's a little electric motor here where I move my mouse pointer. There's bolts or screws that attach to the side of the heating box. So those are sort of on the four corners there.

As I said this motor can be taken apart quite easily. It actually clips apart, which is kind of neat. Of course, you can't repair it. There are no parts available, but this is what you find inside.

2009 Acura MDX Heater AC Issue

So there's a little electric motor here. Little worm gear drive. Then you've got gears here. And these basically just reduce the speed. You know, the motor turns quite fast. This reduces the speed. So this gear turns. By the time it gets to this gear, things turn very slowly and move very methodically to operate these doors.

Plus it adds some strength to the operation as well. You can see the electrical connection here. There's a number of pins here, and this was what I found kind of cool. When you pull this apart is you can actually, on the other side of this gear, you can see there's a lot of little metal here and these are actually little switches or little contacts, which sends a signal to the computer as to what position the door is in.

2009 Acura MDX Heater AC Issue

So there's a little swipers here for the contacts. So as you move it, say to defrost, this door will move to a certain position. And once two of these contacts connect, then the computer knows it's in the right spot, it'll shut the motor off. So that's kind of how this thing works. Pretty complicated for a little motor and not really very expensive considering all that it does. So that's basically a kind of view of the inside.

Mark: Reminds me of some toys I've dismantled over the years. 

Bernie: Yeah. It's kind of neat. So different blend doors will have different contacts inside depending on what the operation of the motor is. This one being a mode door it sits in a number of different positions, so it's kind of critical that the computer knows exactly where it is because, you know, each position is for either the floor or the face or the defrost. 

Mark: So once you replaced it, was there any programming or reprogramming that needed to happen? 

Bernie: Yeah, great question cuz so many things nowadays require programming or resetting a readjustment. This unit's plug and play, it's all set to go. There's nothing needs to be done. 

Mark: If it was more like a 2019, that might have required reprogramming?

No, I don't think so. There's still a lot of components on cars that don't require programming. Usually it's the module, the control module that if it does, you know, sometimes those need to be programmed, but I'm surprised sometimes that things I expect to need to be programmed, don't actually need to be programmed and then other things do.

But you know, we usually prepare our clients with well, this might need programming. And if it's a module, just add that cost to the estimate. And then if it doesn't need to be programmed, then that's a nice pleasant surprise, you know, when you come in.

Mark: So how are Acura MDX vehicles for reliability? 

Bernie: Yeah, they're very good. I mean, it's a Honda product. If you want a reliable luxury vehicle, I mean, these kind of compete, I guess with Mercedes or BMW SUV, they're much more reliable for sure. Definitely less things go wrong over time. I mean, they are still complex. They can be expensive to fix. They don't last forever. Things do go wrong. But I'd say they're definitely more reliable than the German cars. 

Mark: If you're looking for service for your Acura in Vancouver, the guys to see are Pawlik Automotive. You can reach them on their website, Number one for thousands of things, literally in Vancouver. Or you can call them at (604) 327-7112. Both places you can book your appointment. You have to call or you have to book ahead. They're always busy. Thanks so much for watching and listening. We appreciate it and thank you, Bernie. 

Bernie: And thank you, Mark, and thanks for watching.

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Bernie Pawlik

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