355 The End? Evaporator Unit #63307220

Brake lights work. If they didn't, the F1 system will not engage.

SIDEBAR: In fact, a few years back I had a brake light fail and it blew the fuse in the process. Result? No gear section as the F1 system didn't think I had my foot on the brake and would not select 1st gear.

We having fun yet?

 

Was the system working after that for any period? By repaired, do you mean only the standard 6 driver chips were replaced? Or were all the ECU inputs/outputs checked?

Well, it's up to you where you go from here. If you think it's a power issue, check power on the appropriate ECU and control panel pins.

ECU:
Pin 1 (live battery power)
Pin 3 (key power)
Pin 26 (function unknown, but power when lights turned on)

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HVAC ECU
Pin 3 (key power)
Pin 2 (background lighting power)

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I'll get to this tonight. Thank you for the help!

 

Thanks Ian. That was very helpful information.

I have verified power at all the spots.

So not a power issue.

It's just weird as I get zero response form the HVAC control panel.
No air distribution change
No re-circ flap
No AC clutch engagement.
Fan just spins at slow speed when I have the HVAC control panel fan set to 4 and the fan stops if not on the high setting.

All these components work when I apply power directly.

So, bad ECU?

Mine was rebuilt three months ago by Auto Scientific in Rogersville, TN.

Is there a better re builder to consider?

 

Huh. The P/N for the ECU is 64324800.

Yet, this is what I pulled out:

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That’s just the manufacturer’s part number. It looks the same as other online pics of the ECU.

https://www.ferrariparts.co.uk/part/ferrari/64324800?id=21947

 

I Googled the first number on your ECU sticker and found this used part:

https://www.ebay.com/itm/165464873054

 

Interesting. Even on ECU pin 26 with the lights on?

I can understand light power going to the AC unit on the 348 as that has illuminated buttons, but it seems to serve no purpose on a box hidden in the frunk.

 

I stopped at 1 & 3. I'll try pin 26 tomorrow....

 

Well, I bought it. Wonder if it will work? haha

 

Yeah, it doesn't look the best. Let's hope the damage is limited to one of the mounting posts. If it works, maybe you can put your old case on the "new" one.

I'm glad you were able to buy it. Sometimes when I provide a link to components for sale, someone jumps in and buys it before the original poster sees it.

 

They seem to be rare as hens teeth so why not?

Absolute worst case is I send it to ECU Doctors and they repair it and the one i have and I'll have a back-up.

Thanks for the find. Says it should be here by the 19th. Lets hope it works (and it actually gets here)!

 

Pin #26 => no power with key off
======> no power with key in run position
======> power with parking and/or headlights lights on

 

Thanks!

Certainly a mystery. I don’t have any theories on why it should need this power, but it’s good to know your car matches the wiring diagrams.

 

Well, Ebay unit showed up and no joy.

With mine, the fans run slow on 4, slower on 3 and off at 2.
No AC engagement, no air distribution and no recirc flap

With the ebay unit the fans do not run at all
The AC engages, no air dist that I can tell and no recirc flap

This does not change with witch swapping HVAC control panels or fan relay.

Tired of guessing so I popped them open. Dispswitches were different so I tried each the other way. Nothing.

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Very disappointing.

I'm assuming the bottom one is the new one. They look quite different. The driver chips for the actuators seem to be mounted vertically on the lower ECU. I can't say I've seen this before. Are there any differences between the manufacturer part numbers?

Do you mean the blower fan? If there is no blower fan with the new one (whereas the old unit does have fan operation), this suggests that the new unit is broken. I would get my money back.

If you look at the other differences, I suppose you could say that the old unit has a problem controlling the AC compressor ... and "no air dist that I can tell and no recirc flap" with both ECU's may mean the problem is external to the ECU (but does not exclude the new ECU from being faulty).

Regarding the recirc flap system... It is deceptively complex. It's not just a button connected to a flap. It depends on internal and external temperatures. e.g. temperatures sensed by the driver's mirror sensor and cabin air temperature sensor. It might be worth figuring out a way to test the sensors. There are four sensors in the whole system. They seem to have a common earth, but I've forgotten where it is. It may look something like this 348 earth with lots of spade connectors:

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Did you get the chance to warm up the car to operating temperature. The ECU seems to go through some kind of learning process after a battery reset and needs the car to warm up. Pulling the ECU out would simulate a battery reset.

We may have to approach each fault one at a time to make sense of what is going on, including extensive wiring checks between the ECU and the various components, etc. With so many faults, it sounds like something has been chewing at the wiring.

At the end of the day, there is always the chance that a Ferrari SD tool might identify the problem.

 

If your test conditions were equal for both ECUs, then you would indeed have a faulty old ECU (at least in compressor control).

For info: The compressor is turned on by an earth supplied by the ECU. You should be able to simulate this by removing the ECU plug and putting an earth on pin 15 (of the plug).

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If the wiring is visible, it should be a green/black wire.

Because the new panel operated the AC, we know that we don't have a problem with wiring, relays or refrigerant pressure.

 

Thinking.....

The ebay unit appears to be a 360/430 ECU. I like the chipset with heat distribution built in like that.

Agreed on the Re-circ flap....and the whole system having to warm up. Its as if it all has a life of it's own at times.

SD computer is for whimps!

 

Ugh... sorry about that. That explains the price. Hope you get a refund (Did you record the original dip switch positions?).

Revisiting the advertisement, I see it actually says

Ferrari 350 430 AC Air Conditioning Control Module (875240 1462003400).

I think tunnel vision kicked in and I saw the "350" as 355. The "430" is a giveaway though. The 360 and 430 have basically the same A/C system.

 

Pfffft. No worries. I should have seen that as well. Whatever.

Can not help but wonder if we can make it work....but that's another thread. The dipswitch options have me intrigued

 

With so many faults, it may be an ECU internal power supply problem affecting all the driver chips.

Look for typical faults. Maybe a power supply electrolytic capacitor is starting to break down. Also, vibration may have cracked the solder on the ECU connector power pins (where they attach to the circuit board)

What’s that large silvery green/blue component in the top left hand corner?

That SIEMENS mini relay looks interesting. I wonder if that’s for the AC compressor. There may be a direct connection between pin 15 and the relay.

 

There is no component at the top left corner, only some kind of icon printed on the board. Here's a clearer picture, posted earlier by another member:
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Watson, I notice that the jumpers 5 to 8 are "on" on this board and the picture of your original board shows that only 6 to 8 are "on". Was this original setting on your board? If not already, perhaps you can try with 5 to 8 switched on, like on the unit above.

 

Ah, I meant the metal can next to the dip switches. Thanks for the clearer pic... Looks like a crystal oscillator.

 

Check the soldering on these power pins with a magnifying glass (on the other side of the board)

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When the unit was repaired, perhaps the workshop was playing with these dip-switches during the testing (if there was testing).

I have another pic showing the same dipswitch settings as in your photo, Miro.

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Hopefully it's not a 2.7 vs 5.2 Motronics thing.