Datatek
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I don't know off hand, it will be in RAVE in the connector layout section. I will have a look when I can.
Change Hevac Controler
- Thread starter Igor0077
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Okay, just checked with your connector-plan and it seems that I messed up the motors. Now suddenly everything makes sense. Datatek, thanks so much for your help here! Also many thanks to pwood and anyone else who spend some time to help me here!! Wishing you all the most beautiful weekend ever!
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For some reason the Blend & Distrib connector is missing from all the RAVE versions I have. Pinout is the same numbering for all the 16-pin connectors in the P38 though.
Unfortunately RAVE does not say if this is the contact side or the wire entry side !!
Unfortunately RAVE does not say if this is the contact side or the wire entry side !!
Now I corrected the positions of the motors but my problem stays the same.
Questions, followed by questions: Nanocom: If I go to „Inputs „ - „Switches“ everything says GND and this doesn’t change no matter which button on Hevac I press. Is this a sign for a damaged Hevac or what is this telling me?
I‘m wondering how to find out if the controller is the problem or something else.
Questions, followed by questions: Nanocom: If I go to „Inputs „ - „Switches“ everything says GND and this doesn’t change no matter which button on Hevac I press. Is this a sign for a damaged Hevac or what is this telling me?
I‘m wondering how to find out if the controller is the problem or something else.
Datatek
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You have 2 HEVAC's do you not? Unlikely that both would exhibit the same fault, if they do then most likely the problem is external. Do you have the three 12 volt feeds to the HEVAC, 1 that is always live, 1 live in position one of the ignition and one that is live in position two of the ignition switch?
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If Nanocom does not show the HEVAC button presses, also check the "Values" inputs and see if they make sense. Usually no change in values means you have not got communications with the ECU.
Hey Guys, the values I see on Nanocom are looking okay to me.
Yes, have two controllers and both do pretty much the same (or should I say they don‘t?).
I don’t find any power with key in position 0.
I find between 3 and 5 volts in position 1..
I find between 3 and 5 volts in position 2 (ignition on)
I never find 12 volts.
From time to time the motors move when I switch on ignition but I can’t make the distribution motor work - not by controller and also not by Nanocom.
Should I better start thinking about wrecking the car?
Yes, have two controllers and both do pretty much the same (or should I say they don‘t?).
I don’t find any power with key in position 0.
I find between 3 and 5 volts in position 1..
I find between 3 and 5 volts in position 2 (ignition on)
I never find 12 volts.
From time to time the motors move when I switch on ignition but I can’t make the distribution motor work - not by controller and also not by Nanocom.
Should I better start thinking about wrecking the car?
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- Near Heathrow.
No. Test the motors using a 9v battery. Ideally at same time check the feedback potentiometers using multimeter.
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Firstly do not rely on Nanocom for Voltages, because the ECU's tend to give different values some of which are wrong. Check using a voltmeter you have 12V on C244 pins 1, 2 & 3. Also check ground on Pin-4.
Testing the servos needs to be done unplugged from the HEVAC. For each one, connect a multimeter on Ohms between White and Grey. Then move the motor (Black & Brown wires) using the 9V battery & check the ohms reading changes smoothly with no sudden jumps. Finally repeat with multimeter connected between White & Red/Black.
If the potentiometers are open circuit, or any jumps in the Ohms readings, this will cause the ECU to log faults & stop moving them.
For reference, here's the 12V & Ground feeds to the HEVAC.
Testing the servos needs to be done unplugged from the HEVAC. For each one, connect a multimeter on Ohms between White and Grey. Then move the motor (Black & Brown wires) using the 9V battery & check the ohms reading changes smoothly with no sudden jumps. Finally repeat with multimeter connected between White & Red/Black.
If the potentiometers are open circuit, or any jumps in the Ohms readings, this will cause the ECU to log faults & stop moving them.
For reference, here's the 12V & Ground feeds to the HEVAC.
Datatek
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So, if you do not have 12 volts on the pins on my list, nothing is going to work. Where are you taking measurements? Where is the earth point you are using for measurements? I have had one instance of a faulty earth wire to the HEVAC which stopped anything working. I spliced a new earth into the wire at pin #4Hey Guys, the values I see on Nanocom are looking okay to me.
Yes, have two controllers and both do pretty much the same (or should I say they don‘t?).
I don’t find any power with key in position 0.
I find between 3 and 5 volts in position 1..
I find between 3 and 5 volts in position 2 (ignition on)
I never find 12 volts.
From time to time the motors move when I switch on ignition but I can’t make the distribution motor work - not by controller and also not by Nanocom.
Should I better start thinking about wrecking the car?
CO792 8 pin white connector
Pin 1 BECM Feed from RL7– F8 30A.
Pin 2 Engine Compartment fuse box F42 10A.
Pin 3 Engine Compartment fuse box F35 10A.
Pin 4 GROUND.
Pin 5 Heated Front Screen.
Pin 6 BECM (Interior lights circuit)
Pin 7 Aircon RL3
A faulty fuse box can also give trouble, check you have 12 volts at F35 and F42, check relay #7 and F8.
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I always keep a 9v battery and cables in car just incase I need to manually operate the motors. The potentiometers can be funny so and so's at times
Like I wrote before I fist changed the motors when the trouble appeared. When this was not successful I was thinking that the brand new motors might have a problem and bought another brand new kit. So I have two new kits here. One is in the car, one is on my knees. I connected this one again now and have the same problem.
So, I guess it’s not a motor problem for sure. Fuses are good, relais are also good. I find ground and 3 x 12 volts on the white connector.
I start to believe that both controls have the same damage and these are the source of my issues.
Does this make sense? What else could I check?
So, I guess it’s not a motor problem for sure. Fuses are good, relais are also good. I find ground and 3 x 12 volts on the white connector.
I start to believe that both controls have the same damage and these are the source of my issues.
Does this make sense? What else could I check?
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I had this with my original hevac. It had to be repaired as a component had failed on the driver board inside. This gave me a blend motor fault that actually wasn't the motor
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Assuming the motors are not actually short circuit, simple measure the output voltage from the HEVAC when it's trying to move them. If there's no voltage, the output chips are probably blown (most likely due to shorted motors in the past !! )
I have one in the garage waiting for me to replace one of the blend motor drive chips !!
I have one in the garage waiting for me to replace one of the blend motor drive chips !!
Datatek
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Unlikely to have 2 HEVAC's with the same problem.
True. But what else could be the issue? I will check tomorrow if there is power on the pins when forcing the motor.
Keep in mind that the wrong motor works when I force the distrib motor.
If we come to the result that we need to check the hevac controller, could you give it an overhaul with new chips? Do you have a setting where you can proof functions? How much would this cost approximately and how long would it take?
