Air Bleed Failed - Brake Actuator Replacement - Wrong miniVCI?

After getting a C1391 code and diagnosing the brake actuator as having an internal pressure leak, I swapped the actuator with a new one. To be clear, since these are often confused with the brake accumulators, I replaced the brake thingy that attaches to the brake pedal and contains the ECU and stroke simulator.

I got a miniVCI with 1.4.8 firmware and techstream 16.Xxxxxx, and when going through the brake bleeding procedure I got an error once I got to the stroke simulator bleeding process. I kept getting a pop-up error "Air Bleed Failed" with some boilerplate about initial conditions, etc. By having my buddy pump the brakes while I opened the stroke simulator bleed valve and THEN clicking "Next" to start the stroke simulator bleed page, I got the pop-up to not appear. On the page after that, the (second) "bleed front LH brake" page, the error reappeared.

I've done extensive research (with few results) on these issues, and it seems the most likely issue is that I don't have a K Line connection between techstream and the vehicle. After more research, it seems that the miniVCI 1.4.8 doesn't support the K Line, but the 2.X.X does. Again, I'm not even sure if this is the issue, but even if it is I can't seem to find one for sale online (AliExpress, ebay, Amazon). I tried flashing the 2.X.X firmware to the cable but that didn't solve the K Line connection, which was an expected result based on my research.

At this point, I'm strongly considering driving very carefully (possibly late at night) to the dealership two miles away and having them bleed it. I'm expecting $200-250 for that procedure. But I'd like to avoid that if I can do it in my garage. I have access to the Chilton manual through my library but that didn't help. Should I subscribe to TIS for two days/is there something I'm missing that might be in there? I know some relays should be removed in Gen 2's but not for Gen 3...

Thoughts? Ideas?

 

Actually, a couple weeks after I parked the car due to the C1391 I went to check the odometer for unrelated reasons and found the aftermarket, out of warranty 12V sitting at 2.5V (no lights on in the car, etc...just died). So I got an OEM battery and it's been fine. After trying unsuccessfully to get the bleeding procedure to fully complete, the 12V was at 11.5V. I idled the car for half an hour and that got it back up to 13.1V. "Air bleeding failed" still showed up after it was charged to 13.1V. I haven't gotten to the actuator/pump cycling because the bleeding fails before that point.

So far, I've bled all four wheels and the stroke simulator once.

As for the miniVCI, I don't know much about all the different options (openport, etc). I just thought it's a cable that connects the OBDII to the computer, so I find it tricky to determine what cable name/standard I need to do what I want to do. I'm not even sure if the miniVCI is the issue, I just know that when I do the cable check utility it says the K and L lines are NG (not good?). L line is for ECU reprogramming but I'm not sure what K is for.

 

I haven't put the wheels back on yet so I don't know I'd get codes but I'm assuming if I didn't complete the air bleed sequence then I still have air in there.

I now believe I've completed the bleeding:

I was able to use Tech stream 12.20.024 in a Windows XP VirtualBox. I followed the instructions in "Toyota Techstream for ALL Windows | How to Install and get it WORKING Everytime | Landcruiser 200" YouTube video by Jafffa Adventures. It lost connection many times but I was able to skip through the wheel bleed and stroke simulator bleed steps that I'd already completed yesterday. I continued in the process at the second bleeds for the front wheels and then it performed the Actuator Air Bleeding Pattern (lots of beeps, whirrs, and pressure release sounds).

Note: if you get errors prior to getting to this point, you can perform just this step in the "Active Test" menu after you're in the ABS/VSC/TRAC ECU. After that bleed pattern, it performs six sequential Accumulator Zero Down procedures, which can also be performed in the "Active Test" menu. My connection was lost when going through the bleeding tool after three zero downs, so I did three more manually through the "Active Test" menu. From what I've read on other posts here, it seems like that's the last step of the bleed procedure. I don't know if it is (since I didn't technically get to the end) but if anyone can confirm or deny that would be very helpful.

Even after using the VirtualBox with Windows XP, I still was getting "NG" errors in the DLC3 Cable Check test for the K and L lines, so I can confirm that this process is doable with a miniVCI on 1.4.1 firmware. After getting multiple "lost connection" errors, I switched the VirtualBox from USB 1.0 to USB 2.0, and I had already increased the Base Memory to 8192MB and Execution Cap to 98%. This didn't eliminate my issue but it might have made it better - not sure.

Also, the actuator I bought was from Olathe Toyota for about $551.95 plus tax/shipping, P/N 47050-47140. The FedEx truck it was on in Wyoming crashed and Olathe sent me a new one free of charge...and the second one arrived a day after the original one did (two weeks late). So I sent one back to them. Between the holidays, the lost shipment, and the bleeding issues, it's been a month and a half since I've been able to drive my car! Buying gas for my partner's CR-V sure reminds me why we always drive the Prius instead

Now it's time to put the wheels back on. Hopefully my brake accumulator has many more years on it...

 

Yeah the brake pedal felt normal when I was on the jack stands and the codes didn't come back. Currently it has no codes and I think it's good to go.