Testing the Inverter PCB

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rsu9052

New member
Joined
Sep 12, 2024
Messages
3
Location
Quebec, Canada
Greetings Everyone,

I'd like to thank all of the members on this forum for their contributions. I purchased a 2014 Rav4 EV from Blaine, WA in August 2024 and successfully imported the vehicle into Quebec, Canada. I've always liked the body style and its' background story. I've been able to learn a lot already from browsing the posts here and have a deep desire to learn as much as I can about electric vehicles, particularly this one. I suspected there would eventually be issues with the coolant seal...and so it begins...

While in my neighbourhood on the way back from grabbing some coffee, my Rav4 EV stopped accelerating preceded by a light jerk after about 250 km since its' importing. I turned off the vehicle, started it back up and everything looked great until I tried accelerating again and was forced into Neutral after attempting to Drive. This was followed by the Power Steering Failure message and Check EV System warning. Cycling Power on/off got me to my garage where I was able to check the LDU coolant reservoir and speed sensor - it was clear there were issues. I disconnected the coolant hoses and drained the LDU of almost 3L of the "blue kool-aid."

Two weeks ago, I successfully removed the LDU and I'm looking forward to replacing the seals and bearings - I might as well in addition to a coolant loop modification. A negligible amount of coolant was removed from the LDU housing. The rotor and stator look brand new and the inverter-side also looks great. There is no sign of corrosion or damage - nonetheless, all parts have been cleaned and are now dry. Fortunately, the coolant leak was identified early and remedied by way of removing it from the system, keeping the Rav4 tilted towards the passenger side, not attempting to drive it after receiving the first error messages, and taking apart the LDU as soon as I could.

Now, here's where I need some guidance:

Before I order new seals and bearings to rebuild the LDU, I would like to know with certainty that the inverter is okay. Specfically, the inverter control board PCB. Would anyone be able to provide me with guidance on how one could test the inverter PCB? Is this even possible directly or indirectly? Or do I need to take it to someone else who has the right tools and power supply? Any additional information and guidance is greatly appreciated - I'm almost there!

I may have missed providing some details but if you have any questions, please let me know and I'll respond. Thank you very much and I look forward to hearing back from the forums members.
 
Hi,

I just tested the inverter main board outside from the inverter housing due an error, more on this post. It is better to know which error caused the car shifted to neutral you should try TPD availible on this forum once the car is assembled(unassembled will trow a lot of alerts). From my experince try to remove the main board and cable that connect to the ouside D14.

These are some tests:
ENCG to GND D14 resistance almost exactly 20 ohms.
Resistence between ACG and ACG2 to ground 0ohms.
Power supply 12v to PIN 1 and ground to PIN 11 of the D14
0ohms between Main board J2(5,6,7,8) and D14(9,10,15,16)
ENCP and GND 5.4V to ENCG 5V
ACPWR and ACP2 5V

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That was very helpful. Thank you.

The inverter PCB looks good. I also ended up installing the LDU without the gearbox and I was able to get READY mode and turn the motor.

No errors except those from not connecting the HVIL fuse correctly. Once connected correctly, I was able to charge properly and get READY mode - phew.

I'll move onto rebuilding the LDU now.
 
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