Brand New ABS Unit - C1223 trouble codes in TechStream (1 Viewer)

[nicmaxcarter95]

Hello all,

I have never posted before, so any help would be greatly appreciated. I'll post the TLDR in the first paragraph, and the subsequent paragraphs will be the full detail if anyone wants to know the entire story.

I have a 2001 LC, all brake warning lights came on one day. The dealer gave me a print out of all the trouble codes, and they were kind enough to give me the part numbers of which parts they were going to replace. I ordered a new Master Cylinder assembly (part # 47050-60042). I have installed that unit according to the instruction manuals from techinfo.toyota.com, including bleeding the master cylinder and all four calipers, and now I still have two error codes (since the event I got my hands on Toyota Techstream):

C0226: Open or short circuit in hydraulic brake booster solenoid circuit
C1223: ABS Control system malfunciton

The vehicle drives completely normally now, except for the warning lights on the dash (ABS, VSC, and BRAKE warning lights), which makes me very hesitant to drive. I'm worried at any point the accumulator will lose pressure and I will lose braking power.

I am genuinely confused. The C0226 code was not one of the codes present before the new assembly, the C1223 code was present before. My first thought was that I hooked back up the ABS ECU incorrectly, but upon inspection, all of the cable connections have grooves that only allow for one permutation of connection.

There was one symptom that was immediately present during installation. The toyota tech documents instruct to depress the pedal 40 times, then turn the car on and see how long the pump for the accumulator ran for (spec is 30-40 seconds). My pump for the accumulator would run for 3 seconds and shut off, then run again for 3 seconds, and this would continue indefinitely. After extensive bleeding of the master cylinder, now the pump runs for 5 seconds, shuts off, runs again for 25 seconds, and then is done. This always takes exactly 32 seconds, so technically I am within spec, but nobody else I have read mentions their pump cutting off intermittently. Also, the pump will turn back on if I depress the brake pedal twice. I am under the impression that the accumulator should hold pressure for more than two pumps of the pedal?

I have tried using techstream to test the SFR circuit, but every test I run fails before execution as if it cannot communicate correctly with the ABS ECU.

I know that it is not their responsibility, but I gave it a shot and called McGeorge Toyota Parts (I purchased the assembly from them) and asked if they knew of any extra procedures, and all they offered was that I had to bleed the system first.

The odds that a brand new assembly is faulty seems very low to me. So either I installed something incorrectly or there are more problems such as the ABS sensors at the wheel. The installation is pretty straight forward though: four bolts inside the firewall, pin on the brake pedal, reattach brake lines, reconnect pins to ABS ECU, bleed system. Am I missing anything?

Apologies for the long message, many thanks to anybody who gave a read and are willing to give advice.

 

[dbfw]

I'm sure you may have already tried this, but this may factor into others' replies as well. Did you clear the codes after your bleeding was finished, and do they continually come back? I have a new complete master assembly in my 99 LX, AFAIK it is normal for the motor to cycle multiple times, i.e. start, run for a few seconds then stop and start again at first switching of ignition on after sitting overnight. Mine typically cycles twice at the first start of the day.

 

[nicmaxcarter95]

I'm sure you may have already tried this, but this may factor into others' replies as well. Did you clear the codes after your bleeding was finished, and do they continually come back? I have a new complete master assembly in my 99 LX, AFAIK it is normal for the motor to cycle multiple times, i.e. start, run for a few seconds then stop and start again at first switching of ignition on after sitting overnight. Mine typically cycles twice at the first start of the day.

Okay. So the multiple cycles isn't a problem. That puts my mind at ease a bit.

As for resetting the codes. I've tried running the 'reset memory' function under the utility tab multiple times. I've also ran the general health check and each time it keeps saying the DTCs are still present.

It couldn't hurt for me to check the wheel speed sensors, but I'm hesitant to take them out without ordering new ones because I've heard horror stories about them breaking off from age and the rust surrounding the plastic sensors

 

[dbfw]

It's been a while since I've reset a code in techstream, but I don't think the "reset memory" is the way. If I remember correctly, you need to select each trouble code showing on your list and specifically clear it.

Edit: I do get more than two depressions of the pedal before the motor runs again once the accumulator is fully charged. Maybe there's still some air in the system somewhere? Did you replace the complete master assembly with accumulator as well?

 

[nicmaxcarter95]

It's been a while since I've reset a code in techstream, but I don't think the "reset memory" is the way. If I remember correctly, you need to select each trouble code showing on your list and specifically clear it.

I'm sorry. I should have clarified. I meant that the procedures I outlines were in addition to clearing the codes. Tomorrow I'll play with tech stream more and then I'll check all of the electrical connections.

 

[nicmaxcarter95]

Just in case someone else has any similar issues, here was my solution.

One of the main electrical connectors on the side of the ABS unit had a bent pin. The connection on the ABS unit has male pins, while the connection on the vehicles wiring harness is the female end. I discovered this when I was following the toyota tech guidelines and ohming out each of the pins, then I found the bent connection.

I'm not sure if my hands bent the pins when I pulled the new unit out of the packaging or what, but it is resolved now.

 

[Trollhole]

Another thing to look for especially if the vehicle is parked outside at night or near trees and such is a chewed up harness. Critters love to eat the harness coming out of the drivers firewall and to the brake ECU. We have fixed about a half dozen of these.

 

[MountaineerLC]

Just in case someone else has any similar issues, here was my solution.

One of the main electrical connectors on the side of the ABS unit had a bent pin. The connection on the ABS unit has male pins, while the connection on the vehicles wiring harness is the female end. I discovered this when I was following the toyota tech guidelines and ohming out each of the pins, then I found the bent connection.

I'm not sure if my hands bent the pins when I pulled the new unit out of the packaging or what, but it is resolved now.

Thanks for posting up the resolution to your problem. Too often people forget to do so once they fix their issue and it doesn't do the next guy any good.

 

[kwon-offroad]

Thanks for posting up the resolution to your problem. Too often people forget to do so once they fix their issue and it doesn't do the next guy any good.

Agree. Wish there was a tag available on threads where the actual solution could be stickied. Too many times have a read a thread and no solution has been presented by the OP, assuming one was found eventually. Immediately going to the end doesn't guarantee it either as the chatter most often continues after a solution is posted, buried in the thread.

I'll add to this for others: Not sure about the 2001, but on the later model (mine being a 2006) the triangular shaped ABS connector can be slipped onto the unit way too easily in the wrong orientation. Not much force needed. That's where I had my issues after a R&R with a new unit.

 

[nicmaxcarter95]

Agree. Wish there was a tag available on threads where the actual solution could be stickied. Too many times have a read a thread and no solution has been presented by the OP, assuming one was found eventually. Immediately going to the end doesn't guarantee it either as the chatter most often continues after a solution is posted, buried in the thread.

I'll add to this for others: Not sure about the 2001, but on the later model (mine being a 2006) the triangular shaped ABS connector can be slipped onto the unit way too easily in the wrong orientation. Not much force needed. That's where I had my issues after a R&R with a new unit.

Yeah! I saw on another post that someone had that problem. On my 2001, I don't see it being that easy to make that mistake, but then again I am the same guy that spent weeks finding a bent pin!

 

[nicmaxcarter95]

Lastly, I will say, it pays to inspect the pins with a multimeter. The connections on the unit are very difficult to inspect considering that they sit below the sidewall, so the only way I could get a good look was to use my phone camera and a mirror.