ABS, VSC Trac VSC OFF , and Brake Lights Lit, Constant Beep or Alarm Sound, No Brake Pressure (1 Viewer)

[TurbineTester]

ABS VSC Trac and VSC OFF Light have been illuminated intermittently for a few weeks. I just assumed it was a precursor to another P0420 error code (Check engine, VSC TRAC and VSC OFF Lights) or a fouled up wheel sensor which fixed it self after a brake job several years ago, or something benign. Today i was just driving casually along city streets and nothing was hot or over-worked, at least this particular day , and the ABS/VSC lights were lit like they have been recently, and then i get a beeping sound and the BRAKE (normally indicating Parking Brake is engaged) lights up and a beeping started from the dash. Brakes were working fine at the time. So we got to our next destination and i tried turning the truck off and back on and it still beeped like crazy. I went into a store for 20 mins and came out and it was still beeping but now i had no brake pressure unless i stood on the pedal. Several short and slow driving cycles later still have only soft brake response and beeping will not cease. I check the ECU for codes with a bluetooth code reader and there are no codes. I have to get my cable back before i can connect to Techstream and see what that says. Is there any basic troubleshooting i can do to see whats going on?

 

[Manhattan]

I really hope it's not the spendy failure. My brake failure was very similar to what you described - intermittent beeping for a few days, then lots of beeping but the brakes worked... then they didn't.

I'm assuming you're familiar with ACC?

 

[TurbineTester]

I really hope it's not the spendy failure. My brake failure was very similar to what you described - intermittent beeping for a few days, then lots of beeping but the brakes worked... then they didn't.

I'm assuming you're familiar with ACC?

Thanks for the response. I personally have never had intermittent beeping only intermittent ABS/VSC lights then today the Brake Light and Constant Alarm for the very first time coupled with no brake pressure. What was your spendy failure?

ACC?

 

[JunkCrzr89]

I check the ECU for codes with a bluetooth code reader and there are no codes. I have to get my cable back before i can connect to Techstream and see what that says. Is there any basic troubleshooting i can do to see whats going on?

Sounds like your booster assembly has probably kicked the bucket ($2,500 for a new assembly), but could also be a leak somewhere in the system and you're now low on brake fluid, or the booster motor/accumulator died (rebuild the booster motor for $300-500, and/or buy new accumulator for $200).

Most generic bluetooth readers only read engine/powertrain DTCs, not the ABS/VSC/TRAC system, the latter of which you need Techstream for.

To start you off troubleshooting:
1) With key OFF, pump brake pedal ~20 times or until it drops out (no resistance when pressing pedal).
2) Check fluid level in reservoir. If low, you have a leak somewhere.
3) If fluid not low, then turn key to ON (but do not start engine) and time how long it takes for the booster motor to stop running. Also listen for abnormal sounds from the booster motor (e.g., screeching).

 

[TurbineTester]

Sounds like your booster assembly has probably kicked the bucket ($2,500 for a new assembly), but could also be a leak somewhere in the system and you're now low on brake fluid, or the booster motor/accumulator died (rebuild the booster motor for $300-500, and/or buy new accumulator for $200).

Most generic bluetooth readers only read engine/powertrain DTCs, not the ABS/VSC/TRAC system, the latter of which you need Techstream for.

To start you off troubleshooting:
1) With key OFF, pump brake pedal ~20 times or until it drops out (no resistance when pressing pedal).
2) Check fluid level in reservoir. If low, you have a leak somewhere.
3) If fluid not low, then turn key to ON (but do not start engine) and time how long it takes for the booster motor to stop running. Also listen for abnormal sounds from the booster motor (e.g., screeching).

Thank you so much for your help and the diagnostic steps so far. Here is the result of the steps you suggested:

1-I pressed the pedal 20-40 times but it never got to the point where there was no resistance. Rather there is very little resistance for the first half of travel and then increasing resistance after that until it reaches the travel limit.
2-The fluid level in the reservoir is actually slightly above the MAX line and does not change when I press the pedal.
3- After turning the key to ON I never hear the booster motor come on. I can hear several relays or solenoids cycling when I switch to ON, then one relay that cycles on then off about every 10 seconds. Of course the whole time the alarm is sounding in the dash.

 

[MissouriLC]

ABS VSC Trac and VSC OFF Light have been illuminated intermittently for a few weeks. I just assumed it was a precursor to another P0420 error code (Check engine, VSC TRAC and VSC OFF Lights) or a fouled up wheel sensor which fixed it self after a brake job several years ago, or something benign. Today i was just driving casually along city streets and nothing was hot or over-worked, at least this particular day , and the ABS/VSC lights were lit like they have been recently, and then i get a beeping sound and the BRAKE (normally indicating Parking Brake is engaged) lights up and a beeping started from the dash. Brakes were working fine at the time. So we got to our next destination and i tried turning the truck off and back on and it still beeped like crazy. I went into a store for 20 mins and came out and it was still beeping but now i had no brake pressure unless i stood on the pedal. Several short and slow driving cycles later still have only soft brake response and beeping will not cease. I check the ECU for codes with a bluetooth code reader and there are no codes. I have to get my cable back before i can connect to Techstream and see what that says. Is there any basic troubleshooting i can do to see whats going on?

Please check out the thread linked in my signature. You have a failed brake booster. It may be only the motor, however, which is a fairly inexpensive fix. Regardless, first step is to pull the whole master cylinder assembly. Check out the linked thread for procedures and troubleshooting. Good luck!

 

[Magikarp]

I had the same issues 3 times in the last 2 years. First 2 times replaced with the reman booster fixed it for 12 months then it came back again. Finally decided recently to buy the new assembly ($2500) to get rid of those terrible sounds and lights.

 

[TurbineTester]

Please check out the thread linked in my signature. You have a failed brake booster. It may be only the motor, however, which is a fairly inexpensive fix. Regardless, first step is to pull the whole master cylinder assembly. Check out the linked thread for procedures and troubleshooting. Good luck!

Are the ABS/VSC light symptoms of the failed brake booster that will be returned to normal upon repair, or just the alarm and Brake light?

 

[Manhattan]

The spendy failure is the $2,000+++ booster/MC replacement.

ACC Garage is a killer Land Cruiser shop in Georgia. People literally ship trucks from across the country for restoration, builds, etc. But, locally, they do lot of work on 100s, 200s, GXs, 4Runners, etc. - builds, repairs... About — ACC Garage

 

[JunkCrzr89]

Are the ABS/VSC light symptoms of the failed brake booster that will be returned to normal upon repair, or just the alarm and Brake light?

Symptoms

 

[TurbineTester]

Symptoms

Ok thanks. Hopefully, one way or the other when i get this done i'll no longer have year round Christmas on my dashboard.

 

[TurbineTester]

The spendy failure is the $2,000+++ booster/MC replacement.

ACC Garage is a killer Land Cruiser shop in Georgia. People literally ship trucks from across the country for restoration, builds, etc. But, locally, they do lot of work on 100s, 200s, GXs, 4Runners, etc. - builds, repairs... About — ACC Garage

Did ACC garage fix your brake problem? What was the actual total cost and what exactly did it include?

 

[Manhattan]

Did ACC garage fix your brake problem? What was the actual total cost and what exactly did it include?

It was several years ago so my memory is fuzzy... it was around $2,000 and (getting fuzzier) pretty sure it was the MC, booster and computer.

 

[TurbineTester]

Please check out the thread linked in my signature. You have a failed brake booster. It may be only the motor, however, which is a fairly inexpensive fix. Regardless, first step is to pull the whole master cylinder assembly. Check out the linked thread for procedures and troubleshooting. Good luck!

Ok, your thread was fairly intimidating to be honest, until i got to the end and discovered that you had a total of around 10 hours in the whole job and only ~$350 in parts in the job you did. I'm fairly mechanical, and doing brake pads, front and rea bumpers, minor electrical installs etc is no big deal. I tend to shy away from having to remove trim panels in the dash and other "pretty" pieces just because i don't like taking the risk of cosmetically damaging something i'll have to look at for years. Plus my local shop is really reasonable on labor rates. One thing i can't get around is the cost of parts, though. If rebuilding the pump motor saves $2,000+ on a repair would be worth the possibility of damaging a Christmas tree fastener. Now that i have access to your (very comprehensive and detailed write up, thank you!) instructions, i feel like i could probably tackle it. Not counting having to bleed the brakes using methods that didn't work well, how long would you say it would take you to do the whole job start to finish using your instructions if you were doing it for the very first time?

 

[JunkCrzr89]

Thank you so much for your help and the diagnostic steps so far. Here is the result of the steps you suggested:

1-I pressed the pedal 20-40 times but it never got to the point where there was no resistance. Rather there is very little resistance for the first half of travel and then increasing resistance after that until it reaches the travel limit.
2-The fluid level in the reservoir is actually slightly above the MAX line and does not change when I press the pedal.
3- After turning the key to ON I never hear the booster motor come on. I can hear several relays or solenoids cycling when I switch to ON, then one relay that cycles on then off about every 10 seconds. Of course the whole time the alarm is sounding in the dash.

Per the FSM, your booster pump motor is dead:
"(b) Turn the ignition switch OFF, depress the brake pedal more than 40 times. When pressure in power supply system is released, reaction force becomes light and stroke becomes longer.
(c) Turn the ignition switch ON, check the pump motor operation noise. If the pump motor does not operate, check and replace the wire harness and pump motor."

However, before proceeding forward with rebuilding or replacing the pump motor, you really should hook-up Techstream to see if other ABS/VSC/TRAC codes are present that might indicate the entire assembly needs to be replaced. Given you heard the relays operating, the ABS ECU is likely OK.

 

[MissouriLC]

Per the FSM, your booster pump motor is dead:
"(b) Turn the ignition switch OFF, depress the brake pedal more than 40 times. When pressure in power supply system is released, reaction force becomes light and stroke becomes longer.
(c) Turn the ignition switch ON, check the pump motor operation noise. If the pump motor does not operate, check and replace the wire harness and pump motor."

However, before proceeding forward with rebuilding or replacing the pump motor, you really should hook-up Techstream to see if other ABS/VSC/TRAC codes are present that might indicate the entire assembly needs to be replaced. Given you heard the relays operating, the ABS ECU is likely OK.

This is good advice. I also outlined the FSM diagnostic procedures on the ABS ECU in the first post of my thread (these diagnostic procedures require only some jumper wires, alligator clips, and a multi-meter). My ABS ECU passed with flying colors, but the pump would still not run, as indicated.

I didn't do this as part of my diagnostic, but once you've completed the FSM diagnostic, you could test the motor directly before pulling the M/C. You will need to painstakingly remove the motor leads from the underside of the ABS unit. I've detailed this in my thread, but it is a pain in the ass to do. You need a mirror, a screwdriver bit on a small 1/4" ratchet, and a lot of patience. Carefully remove the screws from those two lead terminals, and don't drop those screws! Once you've carefully disconnected the motor leads, jumper those leads directly to the battery. It the motor fires up, it's not your motor. Do this numerous times to confirm.

If the motor doesn't fire up, try striking the motor housing with a screwdriver handle of small mallet. This might cause the motor to start. If it does, this is a telltale sign of a worn commutator with a dead spot.

This is about an hour of diagnostics that you should do before pulling the M/C. You're going to need to pull the M/C regardless, but this will indicated whether your looking at an ABS ECU replacement ($$$$$$$) or a motor rebuild/replacement ($-$$$).

 

[MissouriLC]

Ok, your thread was fairly intimidating to be honest, until i got to the end and discovered that you had a total of around 10 hours in the whole job and only ~$350 in parts in the job you did. I'm fairly mechanical, and doing brake pads, front and rea bumpers, minor electrical installs etc is no big deal. I tend to shy away from having to remove trim panels in the dash and other "pretty" pieces just because i don't like taking the risk of cosmetically damaging something i'll have to look at for years. Plus my local shop is really reasonable on labor rates. One thing i can't get around is the cost of parts, though. If rebuilding the pump motor saves $2,000+ on a repair would be worth the possibility of damaging a Christmas tree fastener. Now that i have access to your (very comprehensive and detailed write up, thank you!) instructions, i feel like i could probably tackle it. Not counting having to bleed the brakes using methods that didn't work well, how long would you say it would take you to do the whole job start to finish using your instructions if you were doing it for the very first time?

As I recall, I had the truck down for a total of two weeks. It took me only about 2-3 hours to do the diagnostics and pull the M/C. The under-the-dash work was the hardest/biggest pain. I took my time disassembling the M/C, because I opted to install the rebuilt kit and replace the rubber washers between the reservoir and the cylinder. Thus, I spent a lot of time cleaning, and it took me three days and two dealerships to source all the parts. I probably invested another 3 hours in this.

Meanwhile, I located the local motor shop for the rebuild. They had a lead time of about a week on the rebuild, which corresponded with an out-of-town business trip.

When I got the parts back, I spent about 3 hours carefully reassembling the M/C, and then about another 2 hours reinstalling it in the vehicle.

Re-pressurizing the system, bleeding the brakes, and testing probably took 10 to 12 hours alone, over about 3 days. If I was doing it again, it would take half the time. With a full-time helper, it would go faster as well. So, probably 20 to 22 hours in total. I could probably do it in 13 to 15 if doing it again. Never doing up, but following my instruction, 15 to 18 hours I would guess. I have a spare vehicle, so I took my time, working a couple of hours in the evening over multiple days. If you had all the parts in hand before starting, you should be able to do this in a weekend.

 

[TurbineTester]

As I recall, I had the truck down for a total of two weeks. It took me only about 2-3 hours to do the diagnostics and pull the M/C. The under-the-dash work was the hardest/biggest pain. I took my time disassembling the M/C, because I opted to install the rebuilt kit and replace the rubber washers between the reservoir and the cylinder. Thus, I spent a lot of time cleaning, and it took me three days and two dealerships to source all the parts. I probably invested another 3 hours in this.

Meanwhile, I located the local motor shop for the rebuild. They had a lead time of about a week on the rebuild, which corresponded with an out-of-town business trip.

When I got the parts back, I spent about 3 hours carefully reassembling the M/C, and then about another 2 hours reinstalling it in the vehicle.

Re-pressurizing the system, bleeding the brakes, and testing probably took 10 to 12 hours alone, over about 3 days. If I was doing it again, it would take half the time. With a full-time helper, it would go faster as well. So, probably 20 to 22 hours in total. I could probably do it in 13 to 15 if doing it again. Never doing up, but following my instruction, 15 to 18 hours I would guess. I have a spare vehicle, so I took my time, working a couple of hours in the evening over multiple days. If you had all the parts in hand before starting, you should be able to do this in a weekend.

I'm REALLY glad you posted this. I would like to know if the field manual specifies a replacement of the motor and wiring harness, is that part even available from Toyota? My impression of my reading so far is that the motor itself is not available as a replacement part, but rather the entire assembly is available as a repalcement part for $1,700+...is that correct?

 

[GTV]

My booster motor went out as well, welcome to the club! I wasn’t in the position to rebuild the master at the time but I wish I could have. I ordered a new booster from McGeorge ($772), bled my brakes via Techstream and all has been well.

 

[TurbineTester]

My booster motor went out as well, welcome to the club! I wasn’t in the position to rebuild the master at the time but I wish I could have. I ordered a new booster from McGeorge ($772), bled my brakes via Techstream and all has been well.

I'm assuming you did the booster motor replacement by yourself for that price? Is this what you ordered? How long did that take you? How many months/miles have you been driving after the repair? I'm not really interested in spending 15-20 hours doing the whole project, but if i can do the just the booster motor swap in much less time i might be interested in doing that, or possibly just letting my local garage do the labor and getting just the booster motor part. Thank you so much for your input!