2013 Limited climate control not powering up

Our 2013 limited's climate control module appears to be dead. I purchased a used one that I was told was operational, but it also doesn't work. The digital display back lights work, but nothing else.

Does anyone have a wire diagram of the connector that plugs into the module so I can check for power coming in?

Thanks,
Ken

 

Ramblingman1 started "Factory Service Manual" thread, there are links in there that might help you.

 

Thanks. Unfortunately, didn't help.

 

I'm just going to throw this out there: Is it in "auto" mode? I ask because when it is, the system takes into account what temperature is being asked of it and it requires time for the coolant to come to the temperature that's needed for heating. Once it does, the blower kicks on and you get heat out of the vents. If not does it operate in "manual" mode? Can you adjust blower speed and temperature?

 

I can’t see why the A/C ECU would have failed. They are pretty robust unless shorted or exposed to water/corrosion. The wiring diagram is the same for both manual and dual zone systems with the exception of an added in cabin temp sensor/input from the solar sensor. Your system likely isn’t working with the replacement because it probably is a manual system ECU and not the dual system ECU. They are not cross compatible. The behavior you describe of the climate panel lighting up but not working or displaying anything is textbook for that. Check your fuses to be sure (cabin fuse box, 10A ECU-IGN NO. 2 & 7.5A A/C) with a multimeter. Your 10A ECU IGN NO. 2 is likely good as the climate panel powers up. If both fuses are good, you have the wrong replacement ECU, or the climate panel might be suspect, but again I’ve never heard of that failing before (first time for everything though).

 

Wouldn't that be very easy to verifiy-matching part numbers for original ecu and replacement?

 

When you say "ECU" are you referring to the climate control panel, I'm calling the climate control module? Both the original and the replacement I purchased are the same part number and both have functioning back lights. I thought I checked all the fuses, but I'm not sure I checked the ECU-Ign No. 2. My local dealership checked the 4runner out and determined it was the climate control module.

 

Okay, there's more to the story that I originally thought may not be related to the problem. Last week I was installing a new apple play system I purchased that was suppose to be "plug and play" with all the correct wiring harnesses and maestro datalink component. Following the directions I plug the new unit up and powered up the vehicle and immediately a lead wire going to the obd melted the insulation. I unplug the unit and put the factory system back to test it. Everything worked so I re-installed the climate control module and it was not functioning. It was not connected to the vehicle at the time of testing the new apple play stereo. I checked all the fuses and called our local Toyota dealership the next morning for an appointment explaining the problem and assuming they would repair the the problem, asked them to also check the passenger side vents because they were not blowing hot air prior to the attempt to install a new radio when the heat was on. They diagnosed the problem to be a failed climate control module and it was to blame for the passenger side vents not blowing hot air...basically they said it was failing prior and the act of disconnecting the module and re-connecting it probably finished it off.

 

No, there seems to be some verbiage confusion. There is the climate control panel where temp, fan speed, and zone are controlled via knobs and buttons. This is just a control panel, not a module or ECU. It is secondary to the A/C amplifier ECU and only sends input messages to the ECU (Electronic control unit) which is located behind the glove box. The climate control panel only has 5 wires going to it (Ignition, ground, illumination power, illumination ground, and LIN). The panel and ECU communicate via a single wire LIN bus (Local interconnect network; Panel is secondary node, ECU is master node). This panel is only lighting up (no control or display options) because there is no sync occurring via the LIN bus. If you have swapped the climate control panel and it does the exact same thing, it is the ECU that is the issue, not the panel. Underneath the passenger side of the dash is a kick panel covering the underside of the glove box area. If you pull down on this panel (held in by clips) you can look up and see two black boxes held in a white plastic housing closest to the center of the vehicle. The smaller one is the steering ECU with one connector, and the larger one is the A/C amplifier ECU with three connectors. That is where your issue is.

 

Thanks for clarifying. I appreciate your help!

 

This is important information that should have been included in your original post.

Again, those A/C ECUs hardly ever fail unless they are exposed to moisture, corrosion, or are shorted. Your A/C ECU wasn't failing before but a wrong connection somewhere likely finished it off in short order. TBH, most dealerships don't know how to troubleshoot basics anymore, and in lieu of that they make crap up. Did you purchase a replacement climate control panel from the dealership already while trouble shooting this?

What system did you try to install. What connectors were you plugging in to? Did you disconnect the battery while working on the vehicle? Be specific.

Based on model year, 2010-13, 2014-19, and 2020-24 are somewhat wired differently. A lot of the aftermarket companies like to say "Universal plug and play" when in reality it is not that simple. Did you plug the climate control panel connector into anything related to the new radio?

Which wire shorted at the OBD port? Was there an adapter plugged into it or not? Post a picture.

Frankly any wire that melts insulation should have popped a fuse before getting to that point, and the fact that it got hot enough to do that does not bode well.

The A/C ECU controls 4 servo motors and the blower motor for the automatic climate control zone (2x temp servos, passenger/driver, 1x zone mode, and 1x recirculation). The passenger side servo is probably fine even if the others aren't working or are. The ECU controls the servos via a separate communication bus, and no output from the ECU means the servos don't move.

If your fuses are good, you probably fried the A/C ECU and will need to replace it. Your best bet is to find a matching part number on eBay because a new one is pushing $700 from the dealer. You should also know that any automatic climate control A/C ECU from 2010-19MY will work. 2020-24MY will not (Different programming). Manual A/C ECUs from 2010-24 will not work. If the passenger side motor still is not working after ECU replacement, then you will need to service it, and the servo wire harness (the servo harness connectors have a circuit board and microcontroller in them). If you take this to a dealer, expect to spend over $1400. If you do it yourself, expect to spend anywhere from $200-500 depending on what is fried.

This is an expensive lesson to learn.