Code # Status Message B1421 Current Solar Sensor circuit (passenger side) of rearspeed sensor rh C1278 Current Abnormal change in output signal of rear speed sensor lh C1281 Current Master cylinder pressure sensor output singnal is faulty C1343 Current Hydraulic System (rr) C1346 Current Stroke sensor zero point learning sensor lh C1275 Current Abnormal change in output signal of front speed sensor rh C1276 Current Abnormal change in output signal of front speed sensor lh C1277 Current Abnormal change in output signal of rear speed sensor rh C1278 Current C1272 Current Low output signal of front speed sensor lh C1273 Current Low output signal of rear speed sensor rh C1274 Current Low output signal of rear speed sensor lh P0A93 Current Inverter cooling system performance P0A93 Current Inverter cooling system performance P1121 Current Throttle/pedal position sensor/coolant flow control valve position sensor circuit stuck P1121 History Throttle/pedal position sensor/coolant flow control valve position sensor circuit stuck
Don't sweat the B1421; that just means strong sunshine wasn't on the dashboard solar sensor at the time you got the codes. You're getting generic fortune cookies from somewhere for non-generic codes; for the P1121 code in a Prius, "coolant flow control valve position sensor circuit stuck" is the correct cookie. It has nothing to do with a throttle or pedal position, except some completely other car uses P1121 to mean that.
the 3 way coolant valve was the first code to pop up, check engine light 2 days after I purchased the car, it turns on for 1/2 day to two days, then no check engine for a couple days. Brake and ABS lights were on when I bought the car. 88k miles Florida car. Red triangle of death cam on 2 times, both times after about 30 minutes in drive on the freeway, 1st time it was gone the next morning, second time went off after a couple stops within about 4 hours. No I was not driving that whole time 3 short drives then stopped at each for about an hour. Car runs great, brakes fine, no problems other than irritating lights. I’m guessing an inverter pump on the red triangle of death and a connection issue on the sensors. Been looking for a techstream download and cable, just can’t figure out which version will work on my old xp laptop which cable too.
I bought an OEM valve for the repair, getting smoked headlights, when I do them will do the valve at the same time.
So basically you have to replace the 3 way coolant valve, the inverter coolant pump, and change the coolant (both loops). Do those simple things and see where it leads you next.
