430 HVAC Control Repair?

Check the sensor for interior temp and light sensor

Sometimes a bad sensor can cause those types of issues

 

Do we have any resistance vs temperature charts for any of these sensors, Dominick?

@BlacktopRacing It's rarely the panel that fails. It's mostly just switches and resistors inside. More likely other HVAC components. Have these faults accumulated over time, one by one, or did everything break at once?

For the heat issue, are there any ticking noises suggesting TGK (hot water) valve failure?

 

The sensor on top of the dash detects radiant heat from the sun. It is kind of a light detector.

 

I would look at the data parameters in a good diag tool and see if temperature appears ok

Light sensors on dash are used to direct airflow in HVAC systems ...I can't recall if the 430 has it or not ..usually the red bulb on dash

 

There's a little circular grille between the steering column and the centre console. Air is sucked through the grille with a tiny fan, which flows over an interior temperature sensor. Maybe check airflow with one ply of toilet paper (if the fan is strong enough to move that).

There's also the sensor under the driver's mirror.

As Flash says, it's probably easier to use a scanner to look for faults. I assume the Ferrari SD tool shows temperatures for these sensors?

 

The little suction fan should only need the key on. The fan itself is independent of the AC system. If the toilet paper trick doesn't work, I'm not sure if can hear the fan running above all the other noises (if you put your ear close to it)???

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The fan is required because the sensor may be sitting in warm stagnant air (under the dash). If it's warm there, then the aircon heat is not likely to be commanded on.

 

Sounds like the one.

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Not sure how to test it either. It may produce a variable resistance, but I don't have any resistance values (for given temperatures). The connector is probably hard to get to, also, so you'd have to do checks at the HVAC ECU connector which I recall is also buried in the dash somewhere.

 

The best to start would be looking at all the parameters in the live data stream and see if anything pops out .. also use the activation menu to see if you can control the HVAC etc

If I was near you I would stop by and see what we can do

But the diag tool data stream and activation tests are your best friend

 

I have sporadic function on mine as well from time to time. I'm chalking it up to a sticky blend door or mode door for now as I can usually force a change by toggling either the recirc button or moving the temp from one extreme to the other with the fan on full. I'll eventually hear a blend door or similar flip open in the dash somewhere. There's a lot of insulating foam on these parts that gets sticky after a while. I need to do a dash out eventually, so I won't know for sure until then. In the meantime, I'm making it work with my secret code of button pushes I did have one scenario where the floor was blowing cold and the main vents were blowing hot. That was a weird one. I also have an extra switch panel but I'm too lazy to swap it out and check.

 

Actually, it's mounted on the left side of the evaporator (a few inches behind the interior temp sensor).

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After you read codes ..disconnect battery and see if behavior changes ..that may give more insight if ECU issue

 

You can PM me and we can get in the phone ..

 

Then it’s important that you know how to at least use a quality OBD2 reader and a multimeter (voltmeter/ohmmeter) if you have no local experts for issues like this. Also, you’ll need lots of spare time, patience, basic tools and (still) a big wallet if you’re going to DIY it. You’ll also have to be a contortionist to get into those tight spots.

If you think Pittsburgh is bad, try living in Australia. You have to send some things overseas to have them fixed, not just interstate

Intermittent issues are the worst. Even the experts have to shotgun defects from time to time, i.e. keep replacing components until you find the faulty one.

I bought a second hand TGK (hot water) valve last year just to see what was inside. Looked quite robust. Not sure what fails inside them. Plastic cogs? Potentiometer contacts? This example seemed to be a little sticky at the endstops (on the bench), but I don’t see how you could lubricate it if the parts are always submerged in coolant. Maybe coolant/antifreeze is a natural lubricant.

On earlier cars like the F355, the HVAC ECU (brains) used to suffer from blown “driver chips”. These are the power chips (transistors) which drive components like valves and flapper doors. If these external components are aging or getting sticky, sometimes they blow the chips (due to the higher current required to move these external devices). The chips are easy enough to replace by your average stereo/TV repair guy (if you show them what to change), but if you don’t replace the external devices, you can blow up the new driver chips. The 430 HVAC ECU will have similar driver chips, perhaps with a little better ability to handle more stress, but everything has its limits.

 

After the Ferrari 348, the brains and controller got a divorce.

 

I haven't seen the inside of the F430 HVAC ECU, but this is what it looks like on a F355

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The 6 smaller chips control the flaps/vents/valves. The functions of each chip are known, but the F430 has more flaps and things. The configuration will be different and therefore unknown. You could trace specific pins on the (bright yellow) connector to individual chips, but that sounds like hard work. FAI or the ECU Doctors may be able to help you with the ECU (if required).

 

Still trying to figure that out. Looking at photos of the ECU, it looks like it's mounted on 4 posts with access to the screws on the other side of the firewall? (or should I say "frunkwall")

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What a totally stupid design.

For reference, the connectors are under the dash (right side of photo)

Experts?

 

Definitely separately, but it's still not cheap.... if you can find one. Looks like it's NLA.

P/N 204068

Second hand one here:

https://www.ebay.co.uk/itm/285125624513