please help. cooling fans wont come on

Your coolant valve has nothing to do with your AC not working.

Have you tested the control module where the blower motor connects to? That goes bad and the fan won't come on from that part. It costs about $35 on ebay and I believe I might have a spare part if you want to try.

 

if it's blowing, then it's not that problem.

 

Are you asking about the fans at the radiator? Did you check power to the relays (fuses)? If that's OK, check the relay input signals which come from either the A/C controller or the engine ECU. You might have a controller problem, or a wiring harness problem.

 

The P1121 is a code you can live with indefinitely, at least until heating season. As already mentioned it has nothing to do with your current problem.

If the scanner you're using doesn't use Toyota's Techstream software, there may be codes you're missing. Techstream can also check the health of the ECUs, which may be an issue here. You get Techstream when you buy a MiniVCI for about $25 on eBay or Amazon, and you need an old 32-bit Win7 laptop to run it on.

 

You did check fuses, right? 30A CDS FAN and 30A RDI (fusible link) are the first ones to look at.

Many DIYers have the MiniVCI with Techstream. Most independent Toyota/Lexus/Scion mechanics should have Techstream too.

Does your heater work okay?

 

Might be worth getting any trouble codes from the heat/A/C system that might shed light on what's going on. No scantool needed for that.

-Chap

 

It sounds like you've a good job, checking what you can. At this point, if you don't have Toyota's wiring diagrams and diagnostic tools, you'll need to hire someone.

The CEL is lit due to the P1121 code, but there could also be other Prius-specific codes there that a generic scanner can't read. Those codes could point you in the right direction. The problem could be mechanical (a pressure switch), 12V power or control, or in the network communication system. Or even in the hybrid system, since the compressor is powered that way. Good luck with it.

 

There are trouble codes specific to the HVAC system that are easy to read out without any special scan tool (see the link in post 12).

Also, the repair manual, the wiring diagram, and the "new car features manual" (not to be forgotten, because it explains what all the stuff is, what it's for, and how it works, which the repair manual kind of assumes you've looked at) are available to anyone who scrapes together $15 at techinfo.toyota.com ... that'll cover a two-day subscription, enough to look up plenty of stuff and save what you find.

-Chap

 

Bummer many, if not most seems so far reading, AC related issues don't have a conclusion related to the issues where if even the codes were read via the AC Control and Recirculating buttons held when powering on. I have a code 21 and 76 situation in one of my latest gen 2's, a 2005 Touring, that hasn't blown cold air ever. I swapped the engine, though don't see where I missed anything reconnecting and don't recall any issues that may have caused a leak in the AC circuit, where prior there wasn't AC working per the prior owner. The low pressure side seems to be with my EZ Chill generic meter somewhere in the equilibrium static range of too high or too low. Not for sure, as appears the PSI for the environmental temp can indicate an over or under fill situation and the gauge isn't accurate enough IMO. Of course, I don't have a gauge to detail enough to determine as of yet or maybe I do if my old Yellow Jacket manifold connectors are compatible. Time to get that out of storage and see who has a tank, scale and vacuum pump.

I made this bad video, better watched at x2 speed to detail my quick crude observations where step 5 seems to be the situation, that I'm not certain the origin of the "clicking" noise. Seems might be a quick fix if not a bad fan, compressor or inverter. Wondering also about repairing the inverter in the PCU. Sadly, not enough PCU repairs videos or detailed write ups seems.

 

Reads like the code 76 was resolved with replacing the AC Compressor and sounds like this might be the situation and where I want an automotive mechanics stethoscope now:

 

That can be the fix for a B1476 sometimes, but not necessarily always. The code means the car is having to send a different amount of electrical power to the compressor to make it go than it thinks it should have to. That can be because of a compressor problem, or an amount-of-refrigerant problem, or a couple other possibilities. There are troubleshooting steps in the manual to try to pin down the cause.

The B1421 code is usually nothing to be concerned about (unless you are positive bright sunshine was shining on the dash when you pulled the codes and you still had it anyway). There's more about that code toward the end of this page.

 

Bidirectional scanner like techstream to turn them on. If not on then check fuse, relay, ohm meter to fan motors, wiring

 

I think the noise in the last referenced video was the main observation demonstrating the AC Compressor was bad. Here's what we found when my HVAC man opened the old one up. 2005 Gen2 (05-09) Prius AC Compressor Replaced DTC's B1421 & B1476 - YouTube

Kind of nerve racking not replacing the Condenser, or at least Desiccant found in, though multiple compressor pump outs and vacuums were pulled and measured.

We wound up testing the salvage yard AC Compressor by plugging into the inverter connection after having the system charged correctly. AC Compressor spun, so replaced using after doing all required including flushing the system.

Wound up using TSI Supercool 1234yf EV Electric Vehicle Equivalent POE 4oz for the additional oil and 16oz Shoppro & Supertech R-134a since in a hurry and needed AC since I literally have no sweat glands (XLHED).

Next up window tinting.