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Aircon Diagnostic

Jmaac

By Jmaac,
in Tutorials / DIY / FAQ

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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.

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https://www.sau.com.au/forums/topic/204597-aircon-diagnostic/
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  • 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

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