Defeat P268115 Toyota code for defective flow shutting valve assembly 16260-F0010 Bypass the darn thing - update 06/24 still going strong

Our 2020 Rav4 limited non hybrid had a dash message "Engine maintenance required" "see dealer" that wouldn't go away unless the car was shut off with the heater on and then would stay off until the AC was turned on. This was caused by part number 16260-F0010 valve having too low a coil resistance. Ours measured 2 ohms and should be 14 to 16 ohms. I got the resistance spec from a Russian manual on the web. Later I learned from the Rav4 world forum that another service manual reads the valve resistance should be around 25 ohms. We tried the 25 ohm value and it works also.

These valves are on backorder in the US. The message stayed on and you couldn't switch to a different useful dash display. They were used on other Toyotas also and Toyota can't keep replacements in stock. Are the replacements any better who knows? The valve is normally open and only effects the flow to the heater core. I read it was used to make the engine warm up faster for emissions. Apparenty it is supposed to shut or modulate flow when the AC is on also. My plan was to bypass the valves coil connection with an acceptable value so the nag message would stay off. The AC does still work after the bypass. Purchased on Ebay was a 15 ohm 25 watt resistor shipped for $7.70. https://www.ebay.com/itm/334592248331 A 25 ohm resistor we tried later did work the same. I had some wire and a paper clip to make pins to mate with the valves connector.

Assembled bypass

15 ohm resistor mounted

25 ohm resisitor mounted, This worked too.

No more nag message and the AC works