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AC Issue after Installing New Car Audio Fascia Plate

a_est_1984

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Accord 2.2 i-CTDI
Hi All,

I was wondering if anyone can help me out.

About a month ago I purchased a new Head Unit (Clairon NX404e) and also the the fascia plate (Connects2 CT23HD26) which is by Metra, for my Honda Accord 2.2 i-Ctdi 2006.

After having this installed, I turned on the AC and very shortly I started hearing a cracking/hissing sound from the bonnet and saw some smoke leak.
A few days later the AC stopped working and anytime the AC was switched on the cracking/hissing sound would return. I had it checked and the AC compressor had broken.

So here I am, I went an got the AC compressor replaced, when the garage gassed up the car, the same issue happened again. A Brand new compressor failed. They thought it may have been faulty so ordered a new one, and again the same problem.

So the 3rd time, they then ordered a compressor and a High pressure AC switch, They have gassed the car but its still not cooling, and yesterday I thought let me check it out, so I put on the AC and heard the same sound so turned it off straight away.

The garage is unsure of the issue and feel it could be a blocked AC matrix.

However, I know the problem started immediately after the installation of the new fascia and headunit.

The fascia has built in AC controls, although its dodgy, as the passenger side AC is controlled from the left hand side of the ac control and what not, but I want to see if anyone has had this issue after installing the Connects2 CT23HD26 fascia and if so, can you help me out with what the fix is?

Thanks
Adeel
 
No easy fix for this, the A/C system on the diesel is much more complex than on the petrol cars.

On all the cars (petrols and diesel) the compressor-relay is switched on by the engine ECU, and when the relay closes, that pulls in the compressor-clutch, which makes the aux-belt drive the compressor.

But, all compressors on all A/C systems should cycle on and off, they should not run continually. The "smoke" that you saw was probably refrigerant gas escaping from the pressure-relief in the compressor, presumably because the compressor was not being cycled off. If the compressor continued to run with no refrigerant gas in the system, the seals in the compressor will probably over-heat. But if you still have the other compressors, they may just need new seals, and could be reconditioned.

The engine ECU receives the "on" instruction (and the "off" instruction) from the A/C control unit, which is built into the head unit. I don't know if it's possible, but the only way would be to remove the original A/C control unit from the original head unit and somehow keep that original A/C control unit operational. Otherwise, if there is another A/C control unit in the new head unit, and if that is attempting to control the A/C, well it's got no chance because it will not be able to contend with the sensors in the diesel car A/C.
 
I think they are a US market product designed for the US market Acura TSX which doesn't come in Diesel.
They may work OK with the Petrol Accords in the EU albeit with the LHD/RHD controls swapped over but as you have found out the ICTDI is a different animal entirely and I don't think you are going to have an easy time getting it working.
They are re-flashable I think, have you contacted Connects2 and asked them about a software fix?
 
It will need more than a software fix.
The system in the petrol cars uses a pressure switch, which is in series in the signal path between the A/C control unit output and the engine ECU input. Basically the pressure switch will indicate to the engine ECU that the engine ECU must switch off the compressor when the pressure has gone high i.e. for the engine ECU to turn the compressor on, the pressure switch must be closed and the signal from the A/C control unit must be high.
However, the system in the diesel car uses a pressure sensor, so the A/C control unit measures the actual pressure. The signal path from A/C control unit to engine ECU is direct i.e. the A/C control unit is either high or low, depending on many things that it measures, including actual pressure level, external temperature, and whether the evaporator is being used a heat drain (to make the car cold) or a heat source (to make the car hot in winter when the engine is cold).
 
Thanks for that Brian, a very useful piece of info on how the system works.
I think that we can agree that the fascia replacement is not suitable for the ICTDI as it stands.
 
I don't know if I've uploaded the circuit diagrams for the petrols and the diesel from the Honda ESM, but I have looked at them in the Honda ESM and the A/C piping is very different as are the inputs and outputs to the control unit
 
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