Any ideas? P3009 and info code 526 overheating

Well, not to beat a dead horse, but can we revisit the radiator fan issue? The reason I ask is that I've seen other Toyota dealers miss this, even when pointed to it.

If you have backwards fan blades, the car will stay cool at low speeds, but will tend to overheat at higher speeds, such as on an expressway. It will also tend to overheat when using the A/C, and of course on hot days. You will also see incorrect--and high--indications of outside air temperature, since the air from the radiator is blowing across the sensor. This is especially true at lower speeds.

On my vehicle, the dealer replaced the inverter pump, but I suspect it wasn't actually bad. They were just trying out theories about possible causes. Kind of expensive troubleshooting, but I got a new pump out of the deal. And the dealer never found the real problem.

As Patrick suggested, you can rule this out by verifying that the 7-blade fan is on the right (passenger) side of the vehicle, and the 5-blade fan is on the left side. Although it's conceivable that the motors are reversed, the usual scenario is for the fan blades to be reversed--left/right sides.

 

If the yellow bar is not illuminated over the AC icon, then the AC compressor will not turn on (if the windshield defroster is not turned on.)

I had expected that if DTC P3009 appears, then there must be a problem with the AC compressor or the inverter circuits that power the compressor. However I would not expect the DTC to be logged if the AC compressor is not powered up.

Have you already turned the car IG-OFF? If yes, can it be restarted or not?

 

Referring to the repair manual, when P3009 is logged here is the troubleshooting sequence:

1) disconnect high voltage cable leading from inverter to compressor and measure resistance from ground to each of the three terminals on the inverter. The resistance should be > 2 megohms. If not, replace the inverter.

2) disconnect high voltage cable leading to compressor and measure resistance from ground to each of the three terminals. The resistance should be > 2 megohms. If not, replace the AC compressor.

If the above tests are OK, then:

3) run the AC compressor for 10 minutes. Then turn off the car and leave overnight. Disconnect the cable leading to the compressor and measure resistance as in #2 above, minimum resistance should be > 3 megohms. If not, replace the compressor.

Perhaps you might inquire regarding whether those tests were done. If so, and no problems were found, then the AC compressor is probably bad (but flaky enough so that the problem does not happen while the techs are checking out the car.)

It sounds like you've become expert at disconnecting the 12V battery to reset the ECUs. When you do so, do you leave the battery disconnected at least 5 minutes to let the ECU memory completely clear? I am concerned that you see warning lights associated with the skid control ECU appear when you restore power.

 

Note that the high voltage ground fault is not causing "damage" to the car, to the extent that the systems are continuing to function. This is more of a safety issue. If a ground fault exists, then in the event of an accident that impacts the high voltage system, the car might have an electrical short that would be dangerous.

The fault is either with the inverter, the AC compressor, or the orange high voltage cable connecting the two. The cable is probably 3-4 feet long and you can see it if you look for the AC compressor.

Since your car was in a front-end accident, I am wondering whether the cable might have been damaged?