P1121 code and more....

First check if the ICE coolant level is low. The coolant acts as a lubricant for the valve. Mine stuck, but when I added coolant, it freed up. That was 125,000 miles ago.

JeffD

 

I would normally expect the check engine light to be on if DTC P1121 is logged since that DTC is produced by the engine ECU.

If the (!), ABS and VSC lights are on then you need to figure out what is causing that. A faulty engine coolant valve would not cause those lights to appear. Look for turbulence in the inverter coolant reservoir when the Prius is either IG-ON or READY, which will show that the inverter coolant pump is working.

Also, check the voltage on the 12V bus when the Prius is READY to see if it is ~13.8V. If much lower, then you have a problem with the DC/DC converter in the inverter.

Since your car was converted to plug-in, it is certainly possible that the problem is related to the conversion.

 

Regarding DTC C0205, I suggest you raise up the left front corner of the car and use a jackstand to hold the car up. Remove the tire. Inspect the sensor and the cable leading to it for damage. If you don't see any obvious problems, remove the sensor and look at the tip.

If you still don't see any problems you can either replace the sensor hoping for the best, or you can swap with the sensor at the right front corner and pay your dealer to retrieve the DTC again. Between the two alternatives, I personally would replace the sensor.

DTC C1202 indicates low brake fluid level. I do not think that C0216 is a valid code.

 

The light will usually go off once you drive approximately 25 MPH as long as the problems were resolved. In the past I have repaired wheel sensors specifically and have seen the light turn off automatically once driven.

 

1. Replace the wheel sensor.

2. How did you check the ABS MTR and ABS MTR2 relays? Did you measure the resistance across the switched contacts? If not, this should be done now:

Find the relays and remove them, one at a time. Use a digital ohmmeter to figure out which contacts are for the relay coil. Apply 12VDC to the relay coil terminals so the relay is energized

Use the ohmmeter to measure resistance across the switched contacts. If the resistance is more than 0.5 ohm, replace the relays.

3. If the relays are good and you don't have wiring harness damage then you will have to replace the brake actuator as recommended by your dealer. A cost-saving alternative might be to purchase a used part from a salvage vehicle if the dealer will agree to install that. Of course you would bear the risk if the part does not work.

 

I suggest that you start by replacing just the left front wheel sensor. Then see what happens.

You'll get to decide who is worthy of trust. If the DTC that you posted were in fact logged by the car, then the diagnosis is reasonable.

 

No, this is similar to any other ABS-equipped vehicle. Tightening torque on the sensor bolt is 71 in.-lb

 

It connects behind (towards the top of) the inner fender (aka fender liner).

 

No. This is a very simple process.

Prius is IG-OFF. Loosen the wheel nuts one turn. Raise up the corner of the car, support with a jackstand. Remove the tire. Remove the inner fender liner to the extent needed to gain access to the sensor wiring harness connector.

Remove three bolts to free up the old sensor and the associated wiring harness. Install the new sensor, route the wiring harness and connect it, replace the three bolts and the fender liner, replace the tire, lower the car, tighten wheel nuts to 76 ft.-lb, and you are done.