Brake pressure sensor/ABS system codes and slip indicator issues (1 Viewer)

[scottaskinosie]

Hey community!

First off, thank you all for the amazing support!!! I don’t know what I would do without the support of everyone at IH8MUD.

I have a 2001 Toyota Land Cruiser.

Here is my abbreviated story. My brake pressure sensor was going off so I took it into my favorite shop and then the Toyota dealership. My favorite shop suspected the brake booster but wanted me to take it to Toyota for a second opinion. They also said they couldn’t ping the VSC module and it might need to be replaced as well. Toyota told me I needed a new master cylinder and confirmed the bad module.

I got online and bought a rebuilt master cylinder and module on eBay and installed the new master cylinder using Tommy the tool man’s YouTube video and installed the module and used TechStream to do the calibration (and I did get the lights to flash at the end).

After the repair, periodically my ABS VSC and TRAC lights come on. If I push on the brakes hard they go off but will come on after I drive for a while at random. I pulled the codes from TechStream and get C1223 (abs system failure) C1246 (brake pressure sensor). I messaged the person who sold me the master cylinder and they sent me a new brake pressure sensor which I installed and then bled the brakes and used TechStream to do the air bleed off the ABS. I also replaced the brake pedal positioning sensor (brake light switch) but am still having the same issue with the lights coming.

Additionally, my slip indicator light is coming on and the alarm is sounding anytime I make even the slightest turn of the wheel when I am driving above 30mph. if I turn the wheel the opposite direction it turns off, if I don’t it will apply the brakes for me after a period of time.

I am not sure if these are related, but since they both happened at the same time I thought I would group them together.

Any suggestions on what I should try next?

I’m at a total loss at this point

And if I have missed any important information please let me know!!!

 

[scottaskinosie]

Okay, I have an update.

I was just thumbing through TechStream running through some tests and noticed my steering wheel was at 1155. I was parked in my garage on a level surface with my wheels dead straight.

I ran another memory erase and calibration of the ECU and drove for a while and tested again and my steering wheel is still at the same value.

I have noticed that there is a lot of play in the wheel and it has been difficult to keep straight if I hit a rough patch of road.

I’m having a hard time finding information on the sensor for this. I have looked through the forum but haven’t found quite what I’m looking for.

If anyone has any leads on where to buy this sensor and how to replace it I’d appreciate it!!!

 

[scottaskinosie]

Hey again everyone. I wanted to post another update in case anyone runs into similar issues that I had.

For the break pressure issue, after a short drive on the highway I noticed an intense break pad smell. I checked my calipers and one was totally unresponsive. I replaced my calipers and the brake pressure issue had subsided.

For the slip indicator alarm and brakes applying at random, I noticed a lot of play in my steering and replaced my steering rack bushings with the help of chowcares YouTube video and no more alarm! (It only took me an hour and cost $35)

Hopefully this post helps someone else who is having breaking/slip indicator issues

 

[Patron100LC]

I don’t have an input to your issues, but I think it’s good for the forum that you’re updating your results for future reference.

Good luck!

 

[SteffysLX470]

Hey community!

First off, thank you all for the amazing support!!! I don’t know what I would do without the support of everyone at IH8MUD.

I have a 2001 Toyota Land Cruiser.

Here is my abbreviated story. My brake pressure sensor was going off so I took it into my favorite shop and then the Toyota dealership. My favorite shop suspected the brake booster but wanted me to take it to Toyota for a second opinion. They also said they couldn’t ping the VSC module and it might need to be replaced as well. Toyota told me I needed a new master cylinder and confirmed the bad module.

I got online and bought a rebuilt master cylinder and module on eBay and installed the new master cylinder using Tommy the tool man’s YouTube video and installed the module and used TechStream to do the calibration (and I did get the lights to flash at the end).

After the repair, periodically my ABS VSC and TRAC lights come on. If I push on the brakes hard they go off but will come on after I drive for a while at random. I pulled the codes from TechStream and get C1223 (abs system failure) C1246 (brake pressure sensor). I messaged the person who sold me the master cylinder and they sent me a new brake pressure sensor which I installed and then bled the brakes and used TechStream to do the air bleed off the ABS. I also replaced the brake pedal positioning sensor (brake light switch) but am still having the same issue with the lights coming.

Additionally, my slip indicator light is coming on and the alarm is sounding anytime I make even the slightest turn of the wheel when I am driving above 30mph. if I turn the wheel the opposite direction it turns off, if I don’t it will apply the brakes for me after a period of time.

I am not sure if these are related, but since they both happened at the same time I thought I would group them together.

Any suggestions on what I should try next?

I’m at a total loss at this point

And if I have missed any important information please let me know!!!

Hey there!

I’m having similar issues after replacing my ABS unit with a rebuilt one.

Brakes seem to work fine but I get the ABS VSC OFF VSC TRAC lights. I was able to connect to tech stream and get the same codes as you (C1233 and C1246).

Any guidance as to how to replace the pressure sensor and stop light switch? Or possibly to test them?
New to this whole world so excuse the NOOB questions.

 

[scottaskinosie]

Hey @SteffysLX470!

In my case, it was my brake pedal sensor. It wasn’t coming on until I had the brakes pressed pretty hard so if I was stopped at a stop light it didn’t “know” I was stepping on the brakes so it thought I was having brake pressure issues. This is pretty easy to diagnose, get a mirror and put it behind your car so you can see your brake lights and see how hard you have to press them to get the brake lights to come on. You shouldn’t have to press hard at all for them to light up.

Replacing the brake sensor isn’t difficult, there are several YouTube videos about it. You have to remove the ABS unit and a few other linkages which are easy, the area where the brake pressure switch is located is tight so unless you take the whole brake pedal assembly apart you have you get up in there with some short wrenches.

I also replaced the brake pressure sensor before I realized it was the brake pedal sensor. That isn’t bad either, you just need a big, thin walled deep well socket to get the sensor out/in. The biggest pain is that after you replace the sensor you have to do a break bleed again. Not the end of the world but not the most enjoyable either.

If you have any questions let me know! In the meantime I’ll see if I can dig up the videos I watched to help me do the work

 

[SteffysLX470]

Hey @SteffysLX470!

In my case, it was my brake pedal sensor. It wasn’t coming on until I had the brakes pressed pretty hard so if I was stopped at a stop light it didn’t “know” I was stepping on the brakes so it thought I was having brake pressure issues. This is pretty easy to diagnose, get a mirror and put it behind your car so you can see your brake lights and see how hard you have to press them to get the brake lights to come on. You shouldn’t have to press hard at all for them to light up.

Replacing the brake sensor isn’t difficult, there are several YouTube videos about it. You have to remove the ABS unit and a few other linkages which are easy, the area where the brake pressure switch is located is tight so unless you take the whole brake pedal assembly apart you have you get up in there with some short wrenches.

I also replaced the brake pressure sensor before I realized it was the brake pedal sensor. That isn’t bad either, you just need a big, thin walled deep well socket to get the sensor out/in. The biggest pain is that after you replace the sensor you have to do a break bleed again. Not the end of the world but not the most enjoyable either.

If you have any questions let me know! In the meantime I’ll see if I can dig up the videos I watched to help me do the work

This is super helpful and i really appreciate you taking the time to respond! I'm going to start with the "easy" stuff tomorrow if I have time (Brake light test and also a zero point calibration of the system which I read in other threads is a good idea after replacing ABS module).

Might hit you back up with a few questions if you don't mind and please any helpful videos would be much appreciated!