Urgent, 4runner dead after 2 wks of no use

[simple]

Test the switch, with all the electrical issues you have had the switch may be bad and stuck in the on position.

Yeah, I’ve thought about that, but the button illuminated when I turn on the headlight. Also, the VSC doesn’t turn off when I put it in 4wd and lock the center diff... or am I wrong about the VSC when I lock the center diff?

 

[simple]

Omg. I’m about done with this.

I decided to run techstream again, and got a c1202 code, which comes up with these possible causes:

Low brake fluid level Brake fluid leaks
Faulty Brake fluid level warning switch (Brake master cylinder reservoir assembly)
Brake fluid level warning switch harness is open or shorted
Brake fluid level warning switch circuit poor electrical connection

I’ve tried a zero point calibration through techstream and I went into test mode, which appears to do the same thing?

I also ran a ‘signal check’ and this is what came up

Although, I don’t know what that’s telling me. It says current DTC but when I pull up current trouble codes the board is clear.

 

[Drunner97]

Omg. I’m about done with this.

I decided to run techstream again, and got a c1202 code, which comes up with these possible causes:

Low brake fluid level Brake fluid leaks
Faulty Brake fluid level warning switch (Brake master cylinder reservoir assembly)
Brake fluid level warning switch harness is open or shorted
Brake fluid level warning switch circuit poor electrical connection

I’ve tried a zero point calibration through techstream and I went into test mode, which appears to do the same thing?

I also ran a ‘signal check’ and this is what came up

Although, I don’t know what that’s telling me. It says current DTC but when I pull up current trouble codes the board is clear.

Are you sure the center diff is engaging when you press the switch? Something funky is definitely going on.

 

[simple]

Are you sure the center diff is engaging when you press the switch? Something funky is definitely going on.

I was parked so shifting into 4wd gave a kick and there was a clunk with center diff when the light turned solid. I could try binding the driveshaft a bit on some light turns to verify, but I have no reason to think it’s not engaging.

The lights flashing on start up I don’t know if it’s talking with the system or rather just a verification of the lights working on the cluster itself. I’m going to run techstream tonight again and see any codes that’s pop after driving to work and back. But earlier I ran a ZPC and I also ran a test mode and both the ABS and VSC lights were blinking rapidly which Techstream said to expect. So I believe the VSC computer is atleast talking to techstream.

I mean, the c1202 code is concerning, because I think the open circuit or short is most likely true. I’m interested to see what codes come up after an hour or so driving today.

 

[simple]

Alright, for those that are still interested, I’ve made some progress here. If it wasn’t for this VSC issue, I would never know anything was wrong. I drove around a few days with zero codes. However, I was able to replicate my C1202 code when I unplugged my VSC harness from the master cylinder again. So at this point, that’s not pointing to a legit issue.

I passed the codes above in the pics to a Toyota Mechanic from justanswer.com and he said he wasn’t sure what those codes are but they don’t apply to my 4runner year/make/model etc. He’s convinced it’s my VSC switch. I disagreed, but ended up buying another switch. Unfortunately it's coming from Japan so will be some time to get here.

What I think my problem actually is, was identified while running through an ‘active check’ of all my ABS systems. I started with my ABS/VSC/and TRAC off lights. Interestingly, my TRAC off light (skidding car light) didn’t illuminate. However when I turn my car on, all 3 lights illuminate as part of the normal start sequence.

That made me turn to the TRAC system and started testing the solenoids there. When I tested a solenoid, I would hear a click for a second or so, and it would show ‘ON’ for a second or 2, and then go back to ‘OFF’. However when I tested my ‘TRAC Solenoid (SRMR)’ I got a loud noise from the master cylinder assembly that sounded like static vacuum noise or something and all 3 of my lights, VSC, TRAC, and ABS went off along with the ABS audible warning alarm.

This is a Hail Mary, but does anybody have any idea what that is? And secondary, can anybody do an ohm reading of the middle 2 wires from their ‘VSC off’ switch if you happen to have an 08?

 

[Drunner97]

Wonder if you shorted out something in the master? I hate electrical Gremlins. Have enough of them in my Jetta. haha.

Sent from my Pixel 2 using Tapatalk

 

[simple]

Wonder if you shorted out something in the master? I hate electrical Gremlins. Have enough of them in my Jetta. haha.

Sent from my Pixel 2 using Tapatalk

I replaced the entire master cylinder assembly... so there's a chance this used assembly has something wrong with it... but I don't think that's likely.

 

[thecole1098]

I'm so glad I don't have any of that nanny assisted braking bullshit. Old school master and booster here.

I hate electrical issues with a passion. Sorry I couldn't be of any help.

 

[simple]

No worries. Sweet ride! And thanks for the free bump:thumb3:

 

[S p a r k y]

Post a cluster pic when all is fixed!

 

[PsychoKiller]

not sure where you live, but you might want to check cables underneath. Had a friend who had a similar problem with his jeep. Was driving him crazy, and he finally saw that some critter chewed an electrical cable that shorted out. When he was trying to jump start it, his cables started smoking too. Just a suggestion.

 

[simple]

not sure where you live, but you might want to check cables underneath. Had a friend who had a similar problem with his jeep. Was driving him crazy, and he finally saw that some critter chewed an electrical cable that shorted out. When he was trying to jump start it, his cables started smoking too. Just a suggestion.

Yeah, so I’ve taken a pretty hard look at the wires under the car. The wire loom from the brake assembly essentially is only exposed for a few inches then goes in a pretty hard wire enclosure into the firewall. I’ll pull some of my dash to see if I can identify any wires that looked messed up when it enters the firewall.

Interestingly, on my first deployment the base has an a field that they let you park your car on for a few bucks a month. When I got back I had zero issues but noticed that I left a single candy in my back seat and some rodent got into my vehicle somehow, and ate the wrapper away and candy inside. And left a small present.

Crazy how those things can get in.

 

[simple]

Alright so I think I just had a potential break through, which if true, makes me a complete idiot. My initial question came up with, since it was an 07 actuator, if there was a difference in the Skid ECU between 07/08 that allowed for the change with the VSC off switch. Which would explain why my VSC off switch doesn’t work. But not why my 4WD center diff doesn’t shut off the VSC. Well, the 07 I got it from was a 2WD. So if that’s the case that would explain why locking the center diff is not shutting off the VSC.

Am I crazy with this idea?

Edit - sigh, I think I am crazy. I don’t see a part number difference.

 

[Drunner97]

Alright so I think I just had a potential break through, which if true, makes me a complete idiot. My initial question came up with, since it was an 07, if there was a difference in the Skid ECU between 07/08 that allowed for the change with the VSC off switch. Which would explain why my VSC off switch doesn’t work. But not why my 4WD center diff doesn’t shut off the VSC. Well, the 07 I got it from was a 2WD. So if that’s the case that would explain why locking the center diff is not shutting off the VSC.

Am I crazy with this idea?

Edit - sigh, I think I am crazy. I don’t see a part number difference.

4wd ECU controls the center diff lock, but I imagine the ECU still controls the signal for the VSC. Unless there's a difference in the 07/08 master because you have an additional switch that I don't have. No clue what the difference would be. Maybe [MENTION=66389]BlackWorksInc[/MENTION] can chime in. I'm surprised he hasn't stumbled across this post yet.

 

[bob3dsf]

4wd ECU controls the center diff lock, but I imagine the ECU still controls the signal for the VSC. Unless there's a difference in the 07/08 master because you have an additional switch that I don't have. No clue what the difference would be. Maybe [MENTION=66389]BlackWorksInc[/MENTION] can chime in. I'm surprised he hasn't stumbled across this post yet.

Send him a PM....

Sent from my SM-G920V using Tapatalk

 

[BlackWorksInc]

Before you go an replace the master, get the power brakes working again. Without power brakes on a hydro boost system the pedal will go really low. The power steering fluid is actually the coupling between the pedal and the master. So when there is low ps fluid your pedal will go very low before you hit the master cylinder.

That's GM's "HydroBoost" system, Toyota's are not at all coupled like that. Toyota's use a self-contained electric pump to build hydraulic pressure and store it in the accumulator for use by the solenoid pack & master cylinder.

~
[MENTION=19984]simple[/MENTION]

Sorry I have been late to the party I've been busy with a lot of stuff outside of the forum for the last... shit it's been almost something like 6-8months since I've been really active?

Anyways, it sounds like you may have a 2WD unit in your vehicle which can cause weird issues. Unfortunately I am not entirely sure if you can tell if it's 2WD or 4WD as the black ECU on the side of the unit is not available separate of the master cylinder but the part number on the actual ECU is not the part number for the assembly.

You can try and Google the part number of the ECU and see if it gets you anywhere. I sorta ran into this a long while back on a customer's car.

http://www.toyota-4runner.org/4th-gen-t4rs/174680-class-participation-time.html I believe was the thread. But basically similar situation, someone at some point put a 4WD unit in a 2WD vehicle and it caused issues.

The ABS/VSC/TRAC System is specific to 2WD or 4WD as there's switches, inputs, and outputs it's looking for. So if you put a 2WD unit in a 4WD vehicle it's probably not setting DTCs because it's not looking for the 4WD stuff (you won't get DTCs for the 4WD system because Toyota didn't start having DTC recording in those modules until something like 2012 or 2014), but you might have an oddball DTC or two regarding some ABS stuff and ECM communication.

This isn't an issue that crops up too often, so I don't have a large sample size to give you really accurate "if this, then that" stuff, the best you can do is maybe call the junkyard you got the unit from and see if the have a record of the vehicle it came out of or at least the VIN which you can run to find out if it's a 2WD or 4WD.

 

[simple]

Thought I would give an update here since my problem is now SOLVED.

Turns out I had the right master cylinder, wrong ABS computer. The Master cylinder is said to be good for 05-09, but the ABS computer changed in 08. This was my bust because I didn’t verify the numbers on the side of my ECu before buying one at a junk yard.


[MENTION=66389]BlackWorksInc[/MENTION] my heart kind of sank when I read your post, because I had just gotten an 89541-35051 ABS/master cylinder assembly from an 08 on eBay. But it was a 2WD. But when it got here, I couldn’t find any differences on partznet for 4WD/2WD part numbers. I installed it myself, thanks to [MENTION=25953]eng208[/MENTION] ‘s thead,www.toyota-4runner.org/4th-gen-t4rs/176224-brake-accumulator-master-cylinder-replacement-squeal-fix.html, it gave me the confidence to try the install myself. It was easier than I thought it would be. And I was able to sell the original for about my labor cost of having the wrong one installed.

So the correct part number fixed everything, and everything is right in the world again. Overall, whatever caused the ABS computer to short, this whole fiasco cost me about 800 bones. Still better than the dealerships 3300 quote.

Fun stuff.

And I cannot thank everybody enough here for all the input and support. You guys make this forum work.

 

[eng208]

Glad my old thread helped some. Apologize for not being here more lately, could have probably saved you the trouble you had. Glad you got it fixed and now you have confidence.