Jump to content
SAU Community

Aircon Diagnostic

Jmaac

By Jmaac,
in Tutorials / DIY / FAQ

 Share

Recommended Posts

Jmaac Proficient

Jmaac

Posted
Posted

Found this on a site somewhere, some people may find it helpful

Airconditioning Diagnostic's

Self-test diagnostic mode..

It is a six step process, although step six is not used for trouble diagnoses.

Step 1. Self-diagnostic test.

To enter diagnostic mode press the OFF button for more than five seconds within ten seconds of turning ignition from OFF to ON.

Step 2. Sensor check.

Step 2 is selected by pressing HOT switch (the red triangle) while in diagnostic mode. The microcomputer detects whether each sensor input signal is within correct parameters. The results are displayed on the screen.

The sensor numbers are as follows:

20 - All is normal

21 - Outside air sensor

22 - Inside air sensor

23 - Water temperature sensor

24 - Intake temperature sensor

25 - Sunload sensor

26 - PBR

27 - Refrigerant temperature sensor

This should tell you if any of your sensors are faulty.

Step 3. Mode door position check.

(This is probably not the cause of your problems but it is a nifty self check to play with). While in step 2, depress the HOT button again. This will operate the mode door actuator, and checks the whether the position detection switch is operating. Again the results are displayed on the display.

The sensor numbers are as follows:

30: Normal

31: VENT

32: B/L (Bi level)

34: FOOT

35: DEFROST/FOOT

36: DEFROST

Step 4: Actuator operation check.

By pressing the HOT button while in Step 3, you can actually send a signal to check the operation of the actuator manually.

Step 5: Sensor recognition check.

Press the HOT switch again and a "5" will be indicated in the display section. If you press the "AMB" button in this status, the display will show the temperature sensed by each sensor. This will give you an indication also of which (if any) are faulty. Temperatures will be displayed in the following order:

5 -> Outside air temp -> Inside air temp -> Suction temp -> Refrigerant temp

Obviously if any of these temps seem excessively different from actual temperatures you have a problem!

Step 6: Calibration

If you depress the fan switch during Step 5, you will go to Step 6 in which you can set the difference between the indicated temperature and sensed temperature. I found this very useful because when I got my car I found I had to set the inside temp to around 22 to feel comfortable even though I knew it was probably more like 20. While in Step 6 press the HOT or COLD buttons to change the display by plus or minus 3 degrees in .5 degree increments.

Link to comment
https://www.sau.com.au/forums/topic/204597-aircon-diagnostic/
Share on other sites
  • 1 month later...
skyline-driver Enthusiast

skyline-driver

Posted
Posted (edited)

you are supposed to press WITH ignition on, coz the A/C needs power to operate.

my cooling sensor needs to be replaced does anyone know where the sensors are and how to change them or put the 2k resistor on? with pictures please

Edited by skyline-driver
taz2008 Enthusiast

taz2008

Posted
Posted

thanks for the info ^ ..it worked

but when i got to step 5..i only got the temperature for the outside and inside air temp. like 27degrees > 28 degrees. and then when i pressed the AMB button, it went back to 5 :S

any idea why its doing this?

and the actuators i only could get 41 to 46. there wasnt any 47. and how should the air be coming out of the vents when i'm in the different actuators between 41- 46? cheers

Jmaac Proficient

Jmaac

Posted
  • Author
Posted (edited)

Unfortunately Im pretty sure you can only see outside temp when running these diagnostics - o/wise it could of been very usefull

Tazz im not sure, theres another aircon diagnostic page in this section - maybe have a look at that

Edited by Jmaac
  • 10 months later...
Damoz Newbie

Damoz

Posted
Posted

Howdy Guys,

In answer to your questions,

Erractic engadgement of A/c Compressor = Busted Pressure sensor.

A/C not Cold = Low Refridgerent levels... (eg. Possible Leak or just needs a regas)

NOTE: this is not something you can do yourself :rolleyes: you must have a A/C Licence.. due to the Tight

Regulations Reguarding to realsing refridgent into the atmosphere...

Any Questions please dont hesitate to E-mail me

Jarvis Tech boy :thumbsup:

Damo

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing


  • Similar Content

  • Latest Posts

    • GTSBoy
      Mistakes were made, my R34 Story

      By GTSBoy · Posted

      I myself AM TOTALLY UNPREPARED TO BELIEVE that the load is higher on the track than on the dyno. If it is not happening on the dyno, I cannot see it happening on the track. The difference you are seeing is because it is hot on the track, and I am pretty sure your tuner is not belting the crap out of it on teh dyno when it starts to get hot. The only way that being hot on the track can lead to real ping, that I can think of, is if you are getting more oil (from mist in the inlet tract, or going up past the oil control rings) reducing the effective octane rating of the fuel and causing ping that way. Yeah, nah. Look at this graph which I will helpfully show you zoomed back in. As an engineer, I look at the difference in viscocity at (in your case, 125°C) and say "they're all the same number". Even though those lines are not completely collapsed down onto each other, the oil grades you are talking about (40, 50 and 60) are teh top three lines (150, 220 and 320) and as far as I am concerned, there is not enough difference between them at that temperature to be meaningful. The viscosity of 60 at 125°C is teh same as 40 at 100°C. You should not operate it under high load at high temperature. That is purely because the only way they can achieve their emissions numbers is with thin-arse oil in it, so they have to tell you to put thin oil in it for the street. They know that no-one can drive the car & engine hard enough on the street to reach the operating regime that demands the actual correct oil that the engine needs on the track. And so they tell you to put that oil in for the track. Find a way to get more air into it, or, more likely, out of it. Or add a water spray for when it's hot. Or something.   As to the leak --- a small leak that cannot cause near catastrophic volume loss in a few seconds cannot cause a low pressure condition in the engine. If the leak is large enough to drop oil pressure, then you will only get one or two shots at it before the sump is drained.
    • GTSBoy
      Help! Leak coming under transmission

      By GTSBoy · Posted

      So..... it's going to be a heater hose or other coolant hose at the rear of the head/plenum. Or it's going to be one of the welch plugs on the back of the motor, which is a motor out thing to fix.
    • MBS206
      Mistakes were made, my R34 Story

      By MBS206 · Posted

      The oil pressure sensor for logging, does it happen to be the one that was slowly breaking out of the oil block? If it is,I would be ignoring your logs. You had a leak at the sensor which would mean it can't read accurately. It's a small hole at the sensor, and you had a small hole just before it, meaning you could have lost significant pressure reading.   As for brakes, if it's just fluid getting old, you won't necessarily end up with air sitting in the line. Bleed a shit tonne of fluid through so you effectively replace it and go again. Oh and, pay close attention to the pressure gauge while on track!
    • Kinkstaah
      Mistakes were made, my R34 Story

      By Kinkstaah · Posted

      I don't know it is due to that. It could just be due to load on track being more than a dyno. But it would be nice to rule it out. We're talking a fraction of a second of pulling ~1 degree of timing. So it's not a lot, but I'd rather it be 0... Thicker oil isn't really a "bandaid" if it's oil that is going to run at 125C, is it? It will be thicker at 100 and thus at 125, where the 40 weight may not be as thick as one may like for that use. I already have a big pump that has been ported. They (They in this instance being the guy that built my heads) port them so they flow more at lower RPM but have a bypass spring that I believe is ~70psi. I have seen 70psi of oil pressure up top in the past, before I knew I had this leak. I have a 25 row oil cooler that takes up all the space in the driver side guard. It is interesting that GM themselves recommend 0-30 oil for their Vette applications. Unless you take it to the track where the official word is to put 20-50w oil in there, then take that back out after your track day is done and return to 0-30.
    • PranK
      My new to me M35 Stagea wagon

      By PranK · Posted

      Nice, looks great. Nice work getting the factory parts also. Never know when you'll need them.
×
×
  • Create New...