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After dumping about $1500 on my air conditioning system, it can still stop or start working suddenly. Once I hit a bump and it started working again. In its current state it blows hot air on full blast, even with the system off and the dead display unit disconnected. The only way to turn off the fan was to pull the fuse. The compressor was replaced twice as well as several other parts. Even if the system's blowing hot air, the compressor engages.
I replaced the display unit but I still have the same problem. I also ordered the climate control ECU (79610-SEP-A44) off ebay. I asked the seller where it's located and he said it was behind the brake pedal and under the carpet. That seems like an insane place for something with two plugs. Anyway, I pulled away the carpet and just found insulation.
Anyone have any idea where this is? I'm dying down here in Texas!
Lord, no. I paid $1500 over the last 4 years for Acura dealerships to replace apparently random parts of the AC system. That doesn't include the 2 Chinese-made compressors the Toyota dealership (where I bought it) replaced. If anyone's going to take wild stabs at whatever the problem is, it might as well be me and save $$$.
BTW, I was on another forum several years ago (somewhere) and a guy said he had the same problem. He said there's a diode or something behind the head unit that the dealership replaced and it fixed his problem, but I didn't really see anything. Do you know what he might have been talking about?
unfortunately im not sure where this diode is.
since your compressor engages. Have you taken a look at the heater control valve to ensure its fully closed?
That valve sits behind the engine. pretty much centered. if you follow the coolant hoses that enter the heater core by the firewall you'll see it.
Its connected by a cable which should open and close depending on your temperature setting.
maybe I can get a better answer for you when I get home.
I'll take a look at the service manual to see where or what this diode is.
I can see the ECU now. I tried unplugging the cables but they're acting like they're glued in! It looks like I lift the tab up to unlock it, and I've tried almost every direction without any luck.
A/C diode B looks like a PITA to get to if it really is high behind the driver's side of the dash. It also sounds like an afterthought ("taped to harness").
Does this ECU control the blower? Like I said, when I press the buttons to change the fan speed, the display works correctly but the fan doesn't change. I can also take the head unit completely out and it will still blow on full. It's only when I pull the fuse that it stops.
Lets try to figure out a few things to help with troubleshooting. If you want to make it faster, please PM me your email address and I'll send over the workbook:
1. Do both fans in the engine bay (radiator and A/C condenser) with the car at operating temp and the A/C on?
2. Do you have the navi or non-navi model?
3. What has been replaced so far, you mentioned 2 compressors.
4. Have you had the refrigerant levels checked?
5. How do you know the compressor clutch is engaging? Have you manually tried to jump it?
6. Have your checked your heater cable to make sure it's not stuck in the open position?
Also try this diagnostic and see if any DTC's pop up:
Lets try to figure out a few things to help with troubleshooting. If you want to make it faster, please PM me your email address and I'll send over the workbook:
1. Do both fans in the engine bay (radiator and A/C condenser) with the car at operating temp and the A/C on?
2. Do you have the navi or non-navi model?
3. What has been replaced so far, you mentioned 2 compressors.
4. Have you had the refrigerant levels checked?
5. How do you know the compressor clutch is engaging? Have you manually tried to jump it?
6. Have your checked your heater cable to make sure it's not stuck in the open position?
Also try this diagnostic and see if any DTC's pop up:
I am having equally frustrating issues with my A/C....of course during the hottest days of the year.
I will try this along with everything else.
I posted some info in this thread https://acurazine.com/forums/3g-tl-p...-08-tl-948303/
Any other ideas appreciated. Really don't want to have to bring car in to dealership unless I have to.
Thanks for posting.....
I am having equally frustrating issues with my A/C....of course during the hottest days of the year.
I will try this along with everything else.
I posted some info in this thread https://acurazine.com/forums/3g-tl-p...-08-tl-948303/
Any other ideas appreciated. Really don't want to have to bring car in to dealership unless I have to.
Thanks for posting.....
You can buy a new compressor as you stated but if the issue is simply low pressure or an electrical issue it won't fix the problem. Trying to pinpoint the issue is the key!
csmeance, the Toyota dealership I bought it from made those diagnoses and (luckily) paid for them! I'll go through your steps tomorrow (my day off) and try to pull together the extensive list of fixes. The ECU in the car looks fairly new and might be one of the things replaced.
I tried to start the diagnostics but I couldn't even do that. This is a base model (no nav), so I held down the OFF button while pressing the RECIRCULATE button 5 times. All it seems to do is turn off the system and toggle the recirculation (no number segments appear where the temperature's displayed). Does this work for an '04 model?
I unmounted the ECU but it didn't help much since there's very little slack in the cables, I can't see how the tab goes in the plugs so I still can't unplug them. I'll cut the cable tie and remove the glovebox support so I can get a good look at the ECU and the plugs.
Hopefully with the 2nd ECU I can run diagnostics and control the fan speed. Thankfully, we're experiencing cooler, non-lethal temps here in N. Texas lately, but if it wasn't I'd probably just sew everything back up and sell it. Which is too bad since I love this car! (The rest of my family hates it since they can't fit in it)
csmeance, the Toyota dealership I bought it from made those diagnoses and (luckily) paid for them! I'll go through your steps tomorrow (my day off) and try to pull together the extensive list of fixes. The ECU in the car looks fairly new and might be one of the things replaced.
I tried to start the diagnostics but I couldn't even do that. This is a base model (no nav), so I held down the OFF button while pressing the RECIRCULATE button 5 times. All it seems to do is turn off the system and toggle the recirculation (no number segments appear where the temperature's displayed). Does this work for an '04 model?
I unmounted the ECU but it didn't help much since there's very little slack in the cables, I can't see how the tab goes in the plugs so I still can't unplug them. I'll cut the cable tie and remove the glovebox support so I can get a good look at the ECU and the plugs.
Hopefully with the 2nd ECU I can run diagnostics and control the fan speed. Thankfully, we're experiencing cooler, non-lethal temps here in N. Texas lately, but if it wasn't I'd probably just sew everything back up and sell it. Which is too bad since I love this car! (The rest of my family hates it since they can't fit in it)
Make sure ignition is not in RUNNING position (III) but in stall mode (accessories only on) when trying to run the diagnostic!
This is the first thread where I found how to self-diagnose the climate control DTCs, and mine popped up with the "I" code. If csmeance or any other users has page 21-33 of the service manual, I'd like to see what that code means - can also PM me. Sorry for going off-topic, but it's one of the more recent ones with AC questions.
Arg...still no luck. The engine's off and ignition is in position "II." Is there any indication when it's running? How long does it take?
The ECUs plugged in but it's not mounted to the body. I don't know if it gets ground from the firewall.
I just ran the self-diagnostic in my 05 non-navi - pretty neat as the climate control will cycle between Hi and Lo temps and fan speeds, took about a minute to run before the "88" and trouble code popped up.
This is the first thread where I found how to self-diagnose the climate control DTCs, and mine popped up with the "I" code. If csmeance or any other users has page 21-33 of the service manual, I'd like to see what that code means - can also PM me. Sorry for going off-topic, but it's one of the more recent ones with AC questions.
Originally Posted by jo-nathanpham
I just ran the self-diagnostic in my 05 non-navi - pretty neat as the climate control will cycle between Hi and Lo temps and fan speeds, took about a minute to run before the "88" and trouble code popped up.
OK, thanks! I'll reattach the ECU to the firewall and see if that works. Does anyone know how to unplug the ECU? I tried pushing the tab up and down, but the plugs still act like they're glued in.
08-12-2016, 10:43 AM
