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Max is gives me hot hot air out of the vents. No cool air, no AC, just hot hot air. I have the digital/electronic climate control in my 98 Max. Even with the climate control off, it still trickles in and feels like Daenerys Targaryen's dragon is breathing fire on my feet.
I think I have the dreaded air mix door problem as seen in the following threads. Not too common of a problem it seems.
I ran through the diagnostics and I'm getting the dreaded "code 26 PBR". I see everyone else in the threads I linked got the same wonderful 26 PBR code. But no one says what PBR stands for.
Question #1. What does PBR stand for?
What's also weird, is that after I ran through the diagnostics, everything fixes itself and I get my AC back etc. The next day though, same problem. I was able to "fix" it twice over the last several days, but it's officially toast and needs to be addressed now.
Question #2. At step 5 (page HA-73), it says to press the Recirculate button after I press the Defrost button and I should see "52". I've tried this about 10 different times, and I can never get "52" to display. Can you guys try this out and let me know what happens on step 5? I don't know if I should care about this or not.
The A/C, heater, defroster and everything on the 98 model works just fine except, air does not blow out of the two center dashboard vents. If I recall correctly, I can't make it to code 52 either.
I have another auto amp that I can swap in to rule that one out. Since everything work, well, sort of.. Other maintenance has taken priority.
I suspect this is an air door mix problem as well.
I went through this with my 97 Max. That car didn't have the auto climate controls but the air mix motor and door is the same.
The PBR is built into the air mix motor. In my case, the cause of the problem was corrosion on the sliding contact fingers inside the motor that created an open circuit. This kind of thing is fixable, but opening up the motor requires a lot of care.
There are gears inside the motor to move the sliding contact fingers and the PBR in proper synchronization, kind of like the timing chain and camshafts. When you open the motor up, all the gears will end up on your workbench because they are interleaved and simply pulling the 2 halves of the motor apart pulls the gears out. There are no alignment marks that I could detect, so if the gears come out, it's replacement time.
Originally Posted by DennisMik
here is a photo of the air mix door motor out of my 97 max. It stopped working because of corrosion on the contact fingers (the green stuff) for the PBR (right half of photo).
You need to remove the arm that connects the motor to the air mix door and push the shaft into the case as you split apart the motor, otherwise the gears will pop off when you split the motor into the 2 halves because they are sandwiched together. If you can get the motor apart without the gears coming off, you need to mark their positions otherwise the contact fingers and the PBR (left half of photo, bottom center) will be out of sync. There is probably an alignment process for the gears when assembling the motor, but there is nothing in the FSM about it since the motor is considered to be a non-repairable unit.
Finally, I can help you! Dennis helped me with the only blowing out the vent problem!
You have the right part number: 27732-2L901
Here's how I did it for the Mode Door Motor (see below though). I gave directions here. You might be able to use a 1/4" drive ratchet with the appropriate socket and extensions instead of the #2 Philips. Not sure, but you'll get it! Think skinny! LOL
But I will say if you only have hot, you most likely have a different problem or this and another. When my Mode Door Motor failed. Everything worked as usual, except it only blew out the vents. Temp worked from A/C 65 degrees to Heat 85 degrees. I'm not sure what motor controls the heat to A/C blend. What Dennis said above.
Most likely the air blend door actuator and/or linkage, so the door stays on full heat. These are right by the ECU and you have a better view from the passenger side. Not a lot out there on this, but it sounds like what you got!
Might be the same motor part number used for both places.I don't know.
You remove the ECU and then you can remove the air mix door motor with a short phillips screwdriver. Going in through the center console could probably be done but it would be harder due to the longer reach. Work from the footwell, either side.
But the key to replacing the motor is removing the ECU. If you don't remove the ECU, you cannot get a screwdriver on the screws.
Looks like I have to keep my 99 going for the foreseeable future and since the other motor that you helped me with is now replaced, most likely, it's a matter of time before this will be next.
Seems like I'll be a little less contorted and with no foot prints on the headliner doing this one hopefully! Watch, the brake switch pukes at the same time! LOL
We all need to pray that Nissan uses many of these parts across several generations, so they still are available when they die off in our cars. Otherwise, parts like these will be a huge nightmare! Electrical parts from salvage places after 22+ years is not a place I am looking forward to.
Thanks again for the "Easy" button! No anxiety to move forward when the time comes!
I was not able to remove the ECU on my car when I changed the air mix door motor on my 97. Plan B was to remove the dash. When I did that, I found out that Plan A is the way, but I couldn't get the ECU out. Since I had the dash out, I was able to improvise Plan C and cut the motor mounting ears off to remove the motor and then get the screws out with a small vice grips. It was not fun.
I was not able to remove the ECU on my car when I changed the air mix door motor on my 97. Plan B was to remove the dash. When I did that, I found out that Plan A is the way, but I couldn't get the ECU out. Since I had the dash out, I was able to improvise Plan C and cut the motor mounting ears off to remove the motor and then get the screws out with a small vice grips. It was not fun.
and if that was my max then it would be plan d, open da windows...
Between 2010 and 2014 I went through a few ECU swaps on the 99 models and posted a thread about how I removed the ECUs. It turned out that the 99 models I have (Maxima and I30) both came with 8mm screws. So I was able to use an 8mm swivel head gear wrench to remove the ECU screws. I don't know how or why those 99 model ECUs have 8mm screws. Possibly they were changed before I got them or it was one of those 99 model differences.
Today I just checked the 98 model's ECU and it uses JIS screws. Oh joy. So I will have my work cut out for me on that one.
Here's a post where you posted a picture of a small Phillips ratchet the tip filed down to make a JIS driver. I actually bought one of those small ratchet drivers from Sears during that time and never used it. I will be using it now.
When I tackle the 98 model, and if I can get the ECU out, I will be looking to change the JIS screws to be 8mm (like the 99 models) so it will be much easier for the next time I need to remove the ECU. Also, I will only use one screw on the easy to reach side upper side of the mount.
Thank you, KP for the part numbers. I think I need to order a new mode door motor for the 98 model because A/C only blows from the side vents and only a small amount from the vents that are in the center of the dash.
Since most of the ECUs that I have removed have been from salvage yard cars that are elevated to allow the under the car access, it seems to be easier for me if the car is lifted so I can reach the ECU area without trying to roll up iinto a ball in the floorboard to reach behind the ECU.
Just checking part numbers using my low-cost Infiniti parts source, I see Part Number: 277322L900 has been superseded by Part Number: 277322L901 that is named an Actuator air mix at a cost of $61.30.
When you ran through the diagnostics, what codes did you get? I imagine codes 31 through 36, and not a 26 code.
Based on your description, you only need 277312L900, whereas I need 277322L901 because I'm only getting hot hot air and my only code is 26.
This is happening on my 98 Maxima. I've only removed ECU's on 99's so far.
If I recall correctly, I made it past code 51, but did not receive a successful code 52. I should try it again. Also, I have another Auto Amp that I can try. I will check again it again by the weekend.
When you ran through the diagnostics, what codes did you get? I imagine codes 31 through 36, and not a 26 code.
Code 26 is the only code for the air mix door motor. It says that the resistance reading of the PBR is not correct. The code 30 series is for the mode door motor and intake door motor. It is rather strange that Nissan didn't put the air mix door is the 30 group.
Sorry for reviving an old thread, newbie here with this exact same problem on my '99 with automatic HVAC.
I ran the diagnostic and found that it blinked both error codes 26 and -26 (PBR open and shorted, from what I can tell in the service manual. How can a resistor be both open and shorted? Anyway...)
Biggest question I have is how to physically get to the air mix door motor? I'm a bit confused by all the various information out there about this part. Am I understanding it correctly that it sits just above the ECU? I looked around my ECU and couldn't really see much, just a big mass of wires zip-tied together. Any guidance whatsoever would be a big help for me.
The air mix door motor sits above the ECU. It is hard to see.
I found it! Thanks! It looks like I'm going to have to take out the ECU in order to get to the screws holding the motor in. Is there a link somewhere on here to a how to on removing the ECU?
I found it! Thanks! It looks like I'm going to have to take out the ECU in order to get to the screws holding the motor in. Is there a link somewhere on here to a how to on removing the ECU?
12-29-2016, 08:06 PM
