Aircon stopped working but no codes

[gmac78]

Alright gents,

My aircon was recharged a few weeks back and was nice and cold with no issues, yesterday it stopped working and strangely there is no codes present for it.

I can get the AC clutch to activate from a diagnostics but unable to find an option for testing the engine cooling fan operation.

Tried two different types of diagnostic and neither are showing codes and neither allow testing off the engine fan. I find this a bit strange!

Has anyone else had a similar problem or know where I should be looking here?

Cheers
Gordon

[metalworker0]

i take it yours has a system with one fan only in front of the radiator.?

all the best.mark

[gmac78]

Yeh I had a peak last night and could only see one fan.

[gmac78]

No fuses appear to have gone either?

[metalworker0]

MORE info ..needed as last time in the mk8 section your were talking about a custom sport

so

what is it m8 or custom

fwd or rwd
year

engine size

think 2.2's had a radiator fan control module... that's why ..later and ecoblue ..cant find any info .

all the best.mark

[Altransit]

If the fan doesn't start up when you turn on the A/C, then nothing else will start up. You can test both inputs to the fan using a power probe, or a fused 12v wire.
Are you sure that the system is still gassed? even a tiny leak can drain the system in a very short time.

[gmac78]

Morning,

Apologise, I was a bit light with the details.

It a 2019 Custom Sport 185, so a 2.O Ecoblue FWD.

It's entirely possible the refrigerant has leaked out, but in that case I would expect it to trigger a Low pressure switch, however no faults are logged and if it had a leak that bad surely it would have showed on the vacuum test during the aircon regassing?

In the live data I can't seem to find an actual refrigerant pressure, just an option for the low pressure switches being activated or not.

The fan spins freely by hand and if it had an electrical fault I would expect to see that logged. However I'm just not sure how comprehensive faults codes on vans are compared to cars?

I'll have another play with these two diagnostic kits I've borrowed incase I've missed something....

[metalworker0]

Should be in the custom forum then not the mk8

anyway here's a diagram below from the 2.0 custom ecoblue manual

two relays and two electrical supplies to the fan

some info gleaned from the net ..sorry temperatures in F ..it is a transit but may be other one like v8 3.5 litre version as its a USA forum - they are talking about something else ..but he explains the workings of the fan circuit ..whilst he's at it ..so all good info, obviusly because its a complely different engine the temperatures may vary between this and yours, but only by, im going to i say +/- 2 to 3 degrees

low fan control (LFC) is triggered by the PCM with AC off: 213.8°F is the temp when the PCM commanded the LFC PID to ON. The engine cooled down to 204°F then LFC PID to OFF. The Ambient temp was 78°F. The HFC never was commanded on.

I suspect that you had the A/C off when you saw your coolant gauges temp. You have to be able to know if the LFC or HFC is ON to compare and contrast to engine temp to determine whether the fans are on or off and at what speed is commanded to know if you have a fault.
my 2017 Transit 3.5L EB PCM Pin #4 (VT) is HFC and Pin #23 (GN-BU) is LFC.

[gmac78]

Good point, I posted this in the wrong section alright, woops.

Ok, I had more time over the weekend to play with the OTOFIX diagnostic and have sussed out how it works.

Theres was no code for low refridgerent, however when I scrolled through the live data section I could see the residual pressure was showing 14psi, so I've got a leak somewhere or a sticky Schrader valve?

The condenser looks in perfect condition from the what I can see through the bumper, no dents or punctures from stones etc so nothing obvious that I can see from a visual point of view.

I know they vac test these as part of the charging process, so if there was a substantial leak you'd think it would have failed the test? Perhaps the leak is only showing under pressure though.

Just waiting on the garage to call me back, this will need pressure testing now to see what's going.

Oh the joys if it all!!

Thanks for helping with these wiring diagrams!

I'll keep you updated.

[metalworker0]

Sometimes AC systems have a die in them that fluoresces under UV light (black light)

if you have such a light that is --- for £3.71 ..you can buy this

https://www.ebay.co.uk/itm/205332260850?

Even a tiny leak can discharge the system unseen ..

Don't forget to shine the torch on the condensate pipe that drips under the van ..if it has a leak in the core of the AC unit it will show up there

all the best.mark

[2tall]

I had the weirdest air con problem with my 2018 Transit. Suddenly the air con stopped working. No errors, relay was working, could see that the compressor clutch was moving.

Regassed the system, still no worky. Checked the pressure sensor readings with Forscan and realised that the compressor was not making much pressure when the clutch was pulled.

On further inspection found that the compressor clutch bolt was slightly loose and it had already destroyed the splines. So the clutch was moving but not really working