Prius C water damaged ECU rebuild

Got the Prius C running very well now. Chap, Avi from Hybrid Fix and 3 Prong Paul from Boulder Hybrids have provided outstanding recommendations with this tough water damaged rebuild. Wanted to pass on to the Prius Chat Community how the water impacted one fuel injector. I had San Diego Engine balancing perform a fuel injector flow test. One injector was down 25 percent (75 percent capacity) as shown in the attached. I then had had San Diego Engine balancing try to perform an ultrasonic cleaning of the bad injector and was only able to bring the injector up to 85-90 percent capacity. The bad injector was then swapped out and engine now sounds well. Fuel pressure is good and in spec 47 psi.


To complete the car I am down to 2 ac servo motor codes. These 2 servo motors look like they are hard to swap out on a Prius C.


B1441 Air Mix Damper Control Servo Motor Circuit Passenger Side



B1443 Air Outlet Damper Control Servo Motor Circuit


I also got a P0A80 code this past Sunday when during a test drive battery block 9 went to 12.40 volts while all other battery blocks stayed above 14.35 V (data in the attached). P0A80 was cleared and has not come back yet. I need to decide whether to swap out these cells now or if I can wait awhile (a few weeks).

 

Chap, the Prius C is driving incredibly well. It is fun to drive and get into tight parking spots. I am down to fixing 2 air conditioning codes b1441 and b 1443 and you provided invaluable information in your last response on the servo motors and highlighting that there is also the small wire harness that connects them to the A/C 'amplifier' (or ECU) and that harness isn't just wire, there are integrated circuits in its connections to the motors.


After thinking about what you said I removed the attached plastic piece and was able to get access to the harness for the Air Mix Damper Control Servo Motor Circuit Passenger Side. This is the servo that was giving a code B1441. Just as you said Chap it had an in integrated circuit in its connection to the servo motor. I could not get access to remove the upper screw to remove this servo . I removed the integrated circuit connector from the original servo and was able to plug that connector into a replacement servo that I got on ebay. I then went to techstream and Code B1441 went away as shown in the attached. This proved that the integrated circuit was not the problem and that servo was bad.


Chilton online procedure shows to remove what they call the radiator assembly. R134 removal would be required. As an alternative I am trying to see if I can remove the upper dash and get access to remove the top blower motor housing bolts. If I can get all the blower housing bolts removed I should be able to remove the blower motor housing and get access to remove and replace these 2 servo motors. I have not seen that anyone else on Prius Chat has swapped out these two servis on a Prius C. Any additional feedback by you or other Prius chat members will be appreciated.

 

Chap, i want to update you and the rest of the Prius Chat community. I had the privilege of going to see Avi at Hybrid Fix and spending some time with him twice in the past twin months. While we could not find that anyone on Prius Chat had been able to swap out the two hardest to get to servo motors on a Prius C - (1) the Air Mix Damper Control Servo Motor and (2) the air Outlet Damper Control Servo Motor without the huge job of removing the air conditioning radiator assembly as specified in the repair manual Avi thought it may be possible to remove the top dash and then carefully try to separate the blower casing housing from the attachment areas of the air conditioning radiator assembly. What Avi thought was worth a try to try to save a huge amount of time worked and I was able to successfully swap out both of these servo motors and clear codes B1441 and B1443. 3 Prong Paul from Boulder Hybrids was also very helpful during two phone conversations and with his video on how to remove a top dash on a Gen 2 Prius and the right and left side interior pillar trim panels that cover the curtain air bags. Chap you commented in your previous response that the harness to the servos isn't just wire, there are integrated circuits in its connections to the motors. I wanted to let you know that all the harnesses with the integrated circuits still worked after being exposed to water but all 3 of the air conditioning servo motors failed and were solely what caused codes B1441, B1442 and B 1443. Even though the harnesses with the integrated circuits still worked I decided to swap out the servo harnesses.

 

Mendel, does in fact look like a horror with top dash removed. Chap, Mendel and the rest of the Prius Chat community. I have cold air inside when on the hybrid battery and internal combustion engine (ice) not running. AC compressor is running ok and low pressure Freon line in engine compartment is ok and is cold to the touch. No ac codes exist anymore. After driving the Prius C I recently noticed that when the internal combustion engine (ice) starts cold air stops coming out of the vents and warm air comes out of the vents instead of cold air. It appears that I have a blend door issue and I need to figure out the next step to take. Any recommendations on options for the next step to take will be greatly appreciated.

 

Chap, Mendel, Number 27 and the rest of the Prius Chat Community, thanks for taking time and providing the responses to my last posting. I tried disconnecting the 12v battery and then reconnect ing the 12 v battery but unfortunately I still have warm air coming out of the vents instead of cold air when the internal combustion engine (ice) starts. The cold air stops coming out of the vents as soon as the ice starts. After removing the blower housing again I removed all 3 servo motors, then reinstalled, and then checked all 3 servos with techstream (Air Inlet Damper Control Servo Motor, Air Mix Damper Control Servo Motor, Air Outlet Damper Control Servo Motor) and all data was in spec.


However, I noticed that the gear that mates with the Air Mix Damper Control Servo Motor can be turned 360 deg in either direction. Attached is a picture of the gear that mates with the Air Mix Damper Control Servo Motor. I cannot see if the air mix flapper inside the plastic enclosure is broken or seperated from the shaft I may want to see if I can find a special mirror or camera to try to look inside the plastic enclosure to see if the air mix flapper is broken and is causing the warm air coming out of the vents instead of cold air when the internal combustion engine (ice) starts. If the air mix flapper is broken I will need to do some research to see if I can by a replacement air mix flapper or if I need to buy an entire air conditioning radiator assembly. To install a new air conditioning radiator assembly will be alot more work than the top dash and blower housing disassembly that I have done so far. Any additional comments or recommendations will be greatly appreciated regarding options for next steps to try. This the last outstanding issue that I am trying to resolve with the challenging Prius C water damaged rebuild project.

 

Chap thanks for taking time and providing the outstanding information. It was extremely helpful. I thought of what you said so last night I decided to try taking a picture with an iPhone even though I did not have better inside picture taking equipment available for use last night and with my iPhone was able to see part of the inside air mix gear and part of the shaft that connects to the inside air mix gear to the outside air mix gear mix. See attached picture. The outside air mix gear mix is driven by the air mix servo. I still need to try to understand more of how the air mix works inside the plastic heater box and try to see if I can find a break in the air mix components inside the heater box. I am still trying to decide on what future steps to try.

 

Chap and the rest of the Prius Chat Community - making great progress with blend door issue. Removed blend door servo.


Put together 2 trim tab tools to make one long tool that I used to move the blend door and push it over the cogs so it would turn.


Used shop vac in blower config to blow air into heater housing. Want to do several tests first before reinstalling blower housing and blower motor.


Put Prius C in maintenance mode with techstream and then turned ice on so it would stay running.


Manually turned exterior blend door cog by hand To 3 positions - full open, 1/2 open, full closed.


With ac on car got colder with blend door fully open.


Next step is to reinstall blend door servo and use techstream to check data and perform active tests.

 

Put air mix servo back in. Performed active and passive tests with techstream. Reinitialized air mix servo motor - in spec now. Blower motor housing and blower reinstall is next step.

 

Blower motor housing and blower reinstall is complete. Ac now working correctly when ice is running - I.e. no longer getting hot air out of vents when ice is on and climate control is in ac mode. Chap mentioned that someone else on Prius Chat had fixed a blend door issue without removing the heater box. He was not sure what model Prius it was. I decided to try to reattach the blend door on a Prius C without removing the heater case and what I tried worked. I saved many hours in not having to remove the heater case to fix the blend door. Thanks again to Chap for the information he provided.