Naughty Aircon

[headhurts]

My aircon is being a bit naughty so perhaps if anyone has any suggestions I can take them back to the main dealer.

From cold on auto it will not work, nothing happens the auto light is on but no fans coming on.

The screen demist option works and having cleared the screen and driven about 2 miles the auto function will now come on and work ok.

Sometimes on auto the dual on passenger side will activate, sometimes when adjusting temperature nothing happens the temperature indicator will remain at say 20 and not increase or decrease.

I have taken it to the main dealership and of course by the time I get there it is working ok, they say no fault codes showing and Toyota technical have no reports of this as an issue.

In my possible ignorance I thought it must be a switch or sensor problem and they would take a best guess to fix the car, after all this is the wrong time of year to have aircon problems.

The car is a 2010 2.0 diesel.

Anyone come across this issue or have any suggestions?

[Mistermena]

I take it they pluged it into the aircon piece of kit and there was enough R134a coolant?

[Mistermena]

I take it they pluged it into the aircon piece of kit and there was enough R134a coolant and compessor oil?

[junebug1701]

I would run this diagnostic test first thing while the engine is cold. If any codes show up, take pictures or video of the codes displayed to show the dealer. This procedure is for the RAV4, but may apply to the Avensis as well:

This file will give you a good description of how the system works:

http://rav4world.com/pdf/2006/ac_description.pdf

Then you can try this diagnostic procedure and see if any error codes show up:

CHECK MODE PROCEDURE

1. PANEL DIAGNOSIS (INDICATOR CHECK)

(a) Turn the ignition switch to LOCK.

(b) Turn the ignition switch ON while simultaneously

pressing the A/C control AUTO switch and the REC/

FRS switch.

© Check that all indicators and the display area are

turned on and off 4 times in succession at 1 second

intervals.

HINT:

After the indicator check is completed, the system

automatically enters sensor check mode.

(d) Press the OFF switch to terminate the panel

diagnosis.

2. PANEL DIAGNOSIS (SENSOR CHECK)

(a) Perform the indicator check.

HINT:

After the indicator check is completed, the system

automatically enters sensor check mode.

(b) Press the REC/FRS switch to enter actuator check

mode.

© After the actuator check is completed, press the

AUTO switch to enter sensor check mode.

NOTICE:

The sensor check must be performed again after

the actuator check is completed because sensor

check mode, which starts automatically after the

indicator check, cannot fully detect

malfunctions.

(d) Check the sensor check results displayed on the set

temperature display.

HINT:

• The illustration shows the display when code 21

is output.

• When 2 or more sensor check codes are

detected, the codes are displayed in ascending

numerical order.

• In cases with 2 or more codes, if they are difficult

to read, press the DEF switch to activate the step

operation and display them one by one.

• The codes are displayed in ascending numerical

order as the DEF switch is pressed.

(e) When any sensor check codes are displayed, refer

to the DTC chart (see page AC-39).

(f) Press the OFF switch to terminate the panel

diagnosis.

HINT:

Pressing the REC/FRS switch returns the system to

actuator check mode.

3. PANEL DIAGNOSIS (CLEAR SENSOR CHECK CODE)

(a) Inspect, and repair or replace the malfunctioning

parts.

(b) Clear the sensor check codes.

(1) While pressing the DEF switch during sensor

check mode, press the Rr DEF switch.

HINT:

Sensor check codes can be cleared by removing

the ECU-B2 fuse from the engine room No. 2

relay block for more than 60 seconds.

© Perform the sensor check and confirm that normal

code 00 is displayed.

4. PANEL DIAGNOSIS (ACTUATOR CHECK)

(a) Start the engine and warm it up.

(b) Perform the indicator check.

© When the sensor check is started after the indicator

check, press the REC/FRS switch to start the

actuator check.

HINT:

Perform the actuator check with the engine running.

(d) Check the temperature and blower levels by hand at

each step while the actuator check proceeds from

step 0 to 9 at 1 second intervals (continuous

operation).

HINT:

Each step number is displayed on the set

temperature display.

(e) To display step numbers one by one manually,

press the DEF switch to activate the step operation.

The step number changes each time the DEF

switch is pressed.

HINT:

• Each step number blinks at 1 second intervals

during the step operation.

• The illustration shows the display when step

number 5 is displayed.

(f) Press the OFF switch to terminate the panel

diagnosis.

HINT:

Pressing the AUTO switch returns to sensor check

mode.

[Parts-King]

I dont think the A/C will work below a certain ambient temperature, 5C degrees rings a bell

Kingo

[Daveyonthemove]

If you have it set to a warm temp, like 19-20+ then it won't pump any air into the cabin before the engine temp is warm enough to provide warm air, then it will slowly blow warm air into the cabin until the desired temp is reached.

This might explain why it is working by the time you reach the dealers.

[headhurts]

Thanks for the replies, the aircon is normally on auto and when the car is first started before these issues started the fans would blow at near full power until the engine warmed up and as the car got warm so they would gradually slow down.

Now nothing first thing but I can get the screen blower working.

So there is definitely a problem especially when the car is warm and the aircon adjustment does nothing or changes to dual of its own accord.

I have no idea what checks the main dealer carried out, I trust that they did all in an effort to find the issue.