Air Con Climate Control Temperature

[moobaque]

I just re-ran the self diagnostics on my air con unit and this time it came back with a fault code 26 (PBR)

What sensor is "PBR"?

Cheers

Camden

[Oosh]

This sensor in the front bar on R32's, I've never seen it and my bar has been on and off more times tha i care to remember.

Where is it?

[Magic]

My air con does the same thing (cold when on 18, hot on everything else). It also pumps hot air out the dash vents where it use to only heat from foot wells and cool through dash vents.

Now this could be related or coincidental but mine faulted as soon as I put in my power fc....haven't put the stock ecu back in to prove that this is the case. But im sure if this was an issue everyone with a pfc would have made comment.

Diagnostics also come back with all sensors working correctly. (return air hose is definitely also attached to the dash)

Cheers

Camden

Apparantly it's a very common problem throughout the 32-34 series.

After my car had it's major service at Autobahn by Fabian (been through a handful of GTRs himself), I was driving home and noticed a lot of heat from the vent by my left foot. Called him up when Iwas on my way home, he asked if I had the air con on and I answered 'no', then he told me to try adjusting the climate control knob, sure enough it went cold when i adjusted it left. It was a bit strange considering it still reacted even though all the electrics air con/fanwise were switched OFF.

Skyline air con blows.

[Craved]

well if you dont have it on re-circ mode its always going to blow air through the vent - moreso when windows are open.

[GTR-32U]

yes that little round thing up on the dash is the light sensor..And the Air temp sensor for the climate control is behind that little grill in the radio fascia surround..The wiring can get a little dodgey and sometimes that black tube just slips off...I ended up replacing the sensor on mine..very easy job as I had a spare at the time..play around with it and see how you go

[moobaque]

yes that little round thing up on the dash is the light sensor..And the Air temp sensor for the climate control is behind that little grill in the radio fascia surround..The wiring can get a little dodgey and sometimes that black tube just slips off...I ended up replacing the sensor on mine..very easy job as I had a spare at the time..play around with it and see how you go

But is that the PBR sensor? thats kind of more so my question as im not sure what the PBR is. Wouldn't the sensor next to the radio be the inside air temp sensor? coz thats a different error code again?

Cheers

Camden

[moobaque]

Apparantly it's a very common problem throughout the 32-34 series.

After my car had it's major service at Autobahn by Fabian (been through a handful of GTRs himself), I was driving home and noticed a lot of heat from the vent by my left foot. Called him up when Iwas on my way home, he asked if I had the air con on and I answered 'no', then he told me to try adjusting the climate control knob, sure enough it went cold when i adjusted it left. It was a bit strange considering it still reacted even though all the electrics air con/fanwise were switched OFF.

Skyline air con blows.

I think that's a different issue. I'm not talking about air pumping though even though the unit is off. I'm saying the microcomputer is choosing to pump out the wrong temp and or out of the wrong vents.

But it use to work perfectly up until swapping to a pfc.

Cheers

Camden

[Twizted_seed]

Here's one for ya. My aircon is running fine. But when I hit the AMB button it says that outside is 46.5 degrees c. This is a lie! It says it if the car is going along the highway, in the inner city traffic, even if the engine aint on. This vexes, confuses and annoys me.

PEANUT BUTTER JELLY TIME

Just thought I'd put that out there.

[Marko R1]

But is that the PBR sensor? thats kind of more so my question as im not sure what the PBR is. Wouldn't the sensor next to the radio be the inside air temp sensor? coz thats a different error code again?

Cheers

Camden

ok i tested mine again yesterday in normal sunny conditions, error '25' does not show as this is a common error when testing in a dark area (garage)...now my result is '26' which is also PBR & ive looked in my gtr workshop manual but the images & description are too poor to workout the location of the sensor.

does anyone know where this PBR is located? for me this is the exact symptom im getting as the PBR controls air mix with a door hot/cold.

[benro2]

Interesting! Mine only started having similar problems about a week ago, although possibly I can shed some light on the source of the problem:

With mine, the temperature is mostly held correctly, except sometimes it just decides to go haywire and start pumping hot air, until you set it to 18C and it goes very cold. Leave it there for a few seconds, then turn the temp back up and hopefully it will go back to the correct temp. Sounds very similar to the trouble you guys are having, except maybe not as bad (yet).

However, if you listen very carefully, there is a weird sound coming from under/behind the steering wheel. My car has done this for the past 3 years or so and I've never had a problem until now, but I'm positive it's to do with the climate control, because the noise stops as soon as I set the temp to 18C. The sound is sort of like a small squeaking sound, like a motor going back and forth erratically - not knowing where it should be. As soon as I set it to 18C, I hear the squeaking sound for about a second (as though it is opening some sort of valve all the way) and I get cold air. Set it back to 22C and if it's not working properly, the weird erratic sound comes back. If it decides to work properly on 22C, it's quiet again.

Sounds to me like there's a valve or something back there controlled by an electric motor, and either the input sensor has come unplugged or there is something wrong with the motor itself. Hopefully it's not too hard/expensive to fix! Try listening carefully for that sound I mentioned and hopefully someone knows exactly what it is You could also try switching quickly between 18C and 30C and you may hear the motor adjusting the valve (if there is one!) all the way between its two maximums...?

[Marko R1]

that sounds like the pbr unit which is a small servo that controls a door flap - i'll take a closer look at my car later today & see if i get the same symptoms, im trying to locate this damn pbr unit but have no idea where it is so i think starting under the dash on the drivers side is a good starting point

Interesting! Mine only started having similar problems about a week ago, although possibly I can shed some light on the source of the problem:

With mine, the temperature is mostly held correctly, except sometimes it just decides to go haywire and start pumping hot air, until you set it to 18C and it goes very cold. Leave it there for a few seconds, then turn the temp back up and hopefully it will go back to the correct temp. Sounds very similar to the trouble you guys are having, except maybe not as bad (yet).

However, if you listen very carefully, there is a weird sound coming from under/behind the steering wheel. My car has done this for the past 3 years or so and I've never had a problem until now, but I'm positive it's to do with the climate control, because the noise stops as soon as I set the temp to 18C. The sound is sort of like a small squeaking sound, like a motor going back and forth erratically - not knowing where it should be. As soon as I set it to 18C, I hear the squeaking sound for about a second (as though it is opening some sort of valve all the way) and I get cold air. Set it back to 22C and if it's not working properly, the weird erratic sound comes back. If it decides to work properly on 22C, it's quiet again.

Sounds to me like there's a valve or something back there controlled by an electric motor, and either the input sensor has come unplugged or there is something wrong with the motor itself. Hopefully it's not too hard/expensive to fix! Try listening carefully for that sound I mentioned and hopefully someone knows exactly what it is You could also try switching quickly between 18C and 30C and you may hear the motor adjusting the valve (if there is one!) all the way between its two maximums...?

[Dohmar]

that sounds like the pbr unit which is a small servo that controls a door flap - i'll take a closer look at my car later today & see if i get the same symptoms, im trying to locate this damn pbr unit but have no idea where it is so i think starting under the dash on the drivers side is a good starting point

If ya find out where it is, pls lemme know cause I get this same error

-D