Vesku M Posted June 30, 2012 Report Share Posted June 30, 2012 Air conditioning isn't working with vipec plug-in ecu. I swapped the stock ecu back and all works fine. So the problem must be in vipec. When a/c button is pressed "ac request" input turns on and "aircon clutch" output turns on. Also engine revs drops about 100 rpm for a short time (about half second). Celica ecu has also third pin which has connected to a/c amplifier. Pin Name is ATS (pin 54 in vipec pin chart). What is this pin and Why its not connected to vipec? Quote Link to comment Share on other sites More sharing options...
Scott Posted July 2, 2012 Report Share Posted July 2, 2012 Good afternoon, When the engine revs drop is the compressor clutch engaging, or are the condensor fans turning on? Scott Quote Link to comment Share on other sites More sharing options...
Vesku M Posted July 2, 2012 Author Report Share Posted July 2, 2012 Both compressor clutch and fans are turning on when a/c button was pressed. But they keep engaged only about half second. In vipec both a/c request input and magnetic clutch output are continously on when a/c button is pressed on. Vipec software and firmware are latest if this information is important. Quote Link to comment Share on other sites More sharing options...
Jason Posted July 3, 2012 Report Share Posted July 3, 2012 have you checked the AC request and AC trigger polarity on the stock ECU and set the vipec to match? Quote Link to comment Share on other sites More sharing options...
Scott Posted July 3, 2012 Report Share Posted July 3, 2012 Pin 63 on the ECU is the A/C output from the ECU. It would be worth checking this to see if the output is indeed being driven to GND when PCLink is saying it is on. If the output is driven to GND then the ECU is functioning as it should be. If not, then there is a fault of some sort with the configuration or ECU. Let us know what you find. Scott Quote Link to comment Share on other sites More sharing options...
Vesku M Posted July 3, 2012 Author Report Share Posted July 3, 2012 Checked the pin 63 voltages. - Air con clutch output off / ac button off pin voltage 13.3v - Air con clutch output on / ac button on pin voltage 0v So output is configured ok? What is this third pin named ATS? I do not think that this would be for no reason connected on original ecu? Quote Link to comment Share on other sites More sharing options...
Scott Posted July 4, 2012 Report Share Posted July 4, 2012 It looks like the ECU is functioning as it should be. It could be worth checking at the A/C relay to see what is happening. Perhaps a pressure switch is causing the relay not to turn on. To be honest I do not know what the ATS pin does. I have searched documents to try and find out. I have not come across any information. If the compressor clutch and fan are engaging then it looks like it is not needed by our ECU. Quote Link to comment Share on other sites More sharing options...
Vesku M Posted July 4, 2012 Author Report Share Posted July 4, 2012 I don't think that problem is related to ac relay or pressure switch because when I changed back the original ecu a/c worked fine. And when changed back to vipec a/c did not work. Everything else has stayed same when I tested this ecu change. Quote Link to comment Share on other sites More sharing options...
lekonna Posted July 4, 2012 Report Share Posted July 4, 2012 I don't think that problem is related to ac relay or pressure switch because when I changed back the original ecu a/c worked fine. And when changed back to vipec a/c did not work. Everything else has stayed same when I tested this ecu change. atleast on supra there is some sort of pressure check on the system before the compressor even starts. So with low enough pressure in the system the compressor clutch refuses to engage. don't know which of the myriad of control boxes does this but in my supra the aircon did not work either with the vipec pnp harness. removed the aircon though so not an issue anymore. Quote Link to comment Share on other sites More sharing options...
Scott Posted July 4, 2012 Report Share Posted July 4, 2012 lekonna could be right about another check interrupting or interfering with the A/C working. If the Vi-PEC ECU has the A/C output on (and you've checked this) and the clutch is not engaged then the interruption is at a point after the ECU. Do you know if the ECU directly activates the A/C relay or does it go through something else (like an A/C amplifier) first? Scott Quote Link to comment Share on other sites More sharing options...
Vesku M Posted July 5, 2012 Author Report Share Posted July 5, 2012 There is separate A/C amplifier which controls a/c relay, fans, pressure switch, etc.. The a/c amplifier is connected to ecu through these 3 pins AC1 (pin 52 in vipec chart), ACT (pin 63) and ATS (pin 54). It seems to ATS pin is input on a/c amplifier (like ACT pin). I do not dare to try different connections, without better information, because I fear that the a/c amp breaks down. Quote Link to comment Share on other sites More sharing options...
Jason Posted July 5, 2012 Report Share Posted July 5, 2012 ATS on the AC amp is an output, it's not required for aftermarket ECU's. What is the polarity and drive type set to for your aircon clutch output? Quote Link to comment Share on other sites More sharing options...
Vesku M Posted July 5, 2012 Author Report Share Posted July 5, 2012 What is the polarity and drive type set to for your aircon clutch output? Polarity = Low Drive type = Low Side Quote Link to comment Share on other sites More sharing options...
Vesku M Posted July 5, 2012 Author Report Share Posted July 5, 2012 SOLVED! Air con clutch polarity need to be HIGH. That explains why a/c clutch and fans had engaged half second after that a/c button was pressed. Sonac 1 Quote Link to comment Share on other sites More sharing options...
Jason Posted July 5, 2012 Report Share Posted July 5, 2012 that's usually the case You see this a lot when doing toyota engine conversions with newer engines into older cars, have to make a small circuit to invert the signal. Thankfully it's not difficult to select the right polarity in the vipec software Quote Link to comment Share on other sites More sharing options...
MR2 Australia Posted October 24, 2019 Report Share Posted October 24, 2019 I have this exact same problem with my ST205 and G4 plug in ECU. Can the base map be changed please so future customers don't have the same issue? Thanks Quote Link to comment Share on other sites More sharing options...
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