Technical Marea Air Con

[Pete W]

I have recently bought a marea weekend, and the air con doesn't work. I took it to the local fiat dealer who checked it out for me(unofficially), and they said the pressure switch was at fault, but they didn't know where it was situated in the vehicle. Has anyone any info on this, or any experience on this subject. Any info at all would be usefull. Thanks. Pete.

 

[subija]

3-stage pressure switch is above the dehydrating filter

subija

 

[FiatExpert]

Never had a pressure switch gone faulty on a marea, Usually relay for compresser rusty of faulty, or no gas in system.

 

[subija]

This is what I've posted before.....

To confirm the faulty of the air cond system, Marea has a features to self-diagnose the problem of the air cond ssytem...

Here are the steps to diagnose the a/cond..normally this
diagnose can be done to check any faulty of the a/cond system, appear on the control panel which indicates an anomaly.

Automatic diagnose air/cond for Marea (depend on model)

The ECU of the air/cond unit allows saved errors to be read in 2 ways
1. Fiat lancia tester
2. Via the control panel display when the panel enable to display external temperature (depend on model)

Steps for no 2..as follows:-

1. Set the following configuration
- temperature knob on "HI"
- distribution knob on "Max DEF"
2. Turn the key from STOP to MAR

3. within 10 Sec, turn the ventilation knob thru the this sequence
- "0" - "AUTO" - "0" -"AUTO" - "0"

Any code display...jot it down & inform me, I will tell U meaning of the code...Good Luck.



subija

 

[Pete W]

Thanks for the replies, the compressor is fine, and there is plenty of gas pressure. The system worked fine when the fiat guy put a live feed into the system, so he checked the relays, and said they were fine. He pluged the car into the fiat computor, but it said there were no faults. Will try the self diagnostic, and let you know the results. Thanks again. Pete.

 

[ts86net]

You could also consider taking the car to a A/C specialist. They tend to be much better than mechanics (!). There's a place near me called Alpine-air, or something smiliar, who are very good. I guess this only applies if the car has no warrenty.

<font face="Verdana">-- T.
<font color="maroon">'98 Marea Weekend ELX (1.8 16v).</font id="maroon"></font id="Verdana">

 

[Pete W]

Thanks,ts86net, i took it to the only air con place near me, and all they could do was check the pressure which was o.k.

SUBIJA, did the check as you said and it came up with fault C 11. I think it was that as it came up with the letter C, and a large number one, followed by a small number one.Does that look like a fault code?. Hope to hear from you soon. Thanks. Pete.

 

[subija]

Hi,

Normally after you ran the self-diagnose "the error Cli" will displayed followed by the error code. Try to run the procedure again, if the error code did not display, try to clean or check your temperature sensor at the side mirror. Good Luck!

subija

 

[Pete W]

Tried the procedure again, and it showed fault 00.

 

[futuredoblodriver]

We had our 1.8 elx recharged (gas) at a french kwik fit equivalent while on holiday. (midas) Within 10 minutes the gas was gone. We blame the bell end mechanic who changed the oil before we went away. Must have damaged something.

What the hell was that! common cry of other road users as the doblo over takes up a hill fully laiden at 90

 

[ts86net]

Gas gone probably means a leak somewhere in the system.

<font face="Verdana">-- T.
<font color="maroon">'98 Marea Weekend ELX (1.8 16v).</font id="maroon"></font id="Verdana">

 

[scanny]

If you press the external temp button, does it show the correct temp?

I've a problem where it shows a minus temp even on a hot day. Cos of the the a/c wont cut in cos it thinks its v.cold outside already and it's some sort of inhibitor/pretection.

I tried the procedure above and got 00 as well.

Ordering a replacement temp sensor from Fiat.

 

[Pete W]

Yes as far as i can tell the outside temp is right. I have another vehicle with a temp gauge, and they are about the same. I have managed to get a second hand pressure switch, and a set of relays, so i will try swapping them, and see what happens.

 

[MrB]

Hi, just the info I was after!! Having problems with the aircon on my wife's 1.8elx. The compressor won't turn, I've had this twice before on my Coupe and it's always been the compressor control relay, which on the coop is labelled 12V 20A A727 581 7676504. My question is, where the hell is it on the Marea? I've looked all over the place but I'm damned if I can find it. On the coop it's nice and easy to get at (one of the few things that are!!) on top of the washer bottle.

Any help greatly appreciated.

 

[Pete W]

Swapped the relays, but still no go on the air con.Does anyone know if there is another fuse anywhere, apart from the one next to the relay?. Haven't changed the pressure switch yet, will try that next.

 

[subija]

Hi Pete,

Can you elaborate further "The system worked fine when the fiat guy put a live feed into the system." Was it feed at the compressor cable connection?

Before you change the the pressure switch, try to check the voltage at the pressure switch. Connector cable Pink & Yellow-Green at the switch. Try to check the continuity of the cable as well.

The compressor relay is situated inside the black box infront of the battery. The connector has four cables Brown-black (goes to compressor), light blue-black (goes to a/cond ECU & air/cond controls with car interior temperature sensor), Red-green (goes fuel/injection ECU) & Blue-black (goes to fuse & relay unit inside the car. Try to check the continuity of all the cables.

BTW, FYI,

The compressor may be deactivated only by the three-stage pressure switch or the the engine control ECU. This system is dependent upon the various engine management ECUs as follows:

Engine management system receives compressor activation request signal from control switch A/cond ECU. The same signal also flows thru the 3-stage switch. IF COOLANT CIRCUIT PRESSURES ARE NOT CORRECT, THE SIGNAL IS INTERRUPTED. Lastly the a/cond ECu send command to activate compressor via relay, provided that no other exclusion conditions are present ( maximum power demand, idling etc).

To check system pressure/efficiency.(LOW pressure side & high pressure of the compressor)

1. Compressor not activate: low side 5-6 bar, high side 5-6 bar

2. Compressor activate & RPM1500: low side 1.5-3.0 bar, high side 11-16 bar.

Happy repairng!!!!


subija

 

[Pete W]

Hi subija, thanks for staying with me. I'm not sure where the guy put the feed in, i was watching for the compressor to work, but i know he put the feed in somewhere in the relay box. I will try the feed into the pressure switch, and let you know. Now i know which wires go where i can check them all, and try and find something. Thanks again.Pete.

 

[Pete W]

Hi, Have had the air con checked out by an auto electrician, and he has tracked the problem down to the E.C.U., which he says is not sending a pulse to the relays. He's not sure if you can just change the E.C.U., or if it is coded into the master engine management system. Does anyone know the answer?. Also can anyone tell us where the aircon E.C.U. is located?. Thanks. Pete.

 

[subija]

Since you have ran self-diagnose of the a/cond system with Cli 00 code, the a/cond ECU is okay! I still wonder what the problem too.. Have you checked the 3-stage pressure switch & the continuity of the caable at the compressor supply?

BTW, The Ecu is bolted to the lower part of shroud-distributor units by means of 2 bolts and is easily acccesible from the passenger compartment. A connector for a Fiat/lancia tester is located next to it.

subija

 

[Pete W]

Hi, you'll be pleased to know that the air con is working at last. The auto electrician had to bypass part of the E.C.U. and he put in another relay somewhere, i'm not sure where or how, but at least it works now. Thanks to everyone for their interest, and the replies, they were all gratefully received. All the best. Pete.