master control solenoid failure

[macscac]

hi all..
i have searched..... dont shoot me yet!

the last few weeks... traction control and multi terrain lights have been intermittently flicking on my dash.

took it to dealership today and they told me its pulling the code for
master control solenoid
They want to replace the unit. like $2300.
my truck has 44k miles on it and is 2018

I have read a lot of scenarios where the solenoid is actually bad but also an equal amount of scenarios where someone replaced that solenoid and still had the issues and it ended up being speed sensors or abs harness

my question is, how do i verify that this is the actual problem and not a speed sensor issue or a stretched abs harness?

the truck is at a high volume toyota store and I just dont trust them to dig deep into this.. i think they are just trying to replace what the computer suggests and thats that.

any advice would be great. thank you

 

[flyrv9]

There was a thread a while back where a guy was having a similar problem. If I remember right. He found a badly corroded switch on the side of the transmission as the cause of his problem. It was hard to get to, but doable. I'm sure it didn't cost that much for him to fix it. Perhaps you have the same issue. However, with a 2018 I'd think you'd be covered under warranty.

 

[macscac]

so the shop just called me back and said that "possibly" it was interference with some of my lighting wiring under the hood.

interesting because i did find a thread where someone was getting this issue due to his xenon lights

so who knows.. im going to unplug them and run for a week or so and see what happens..

 

[rigtec]

"...my question is, how do i verify that this is the actual problem and not a speed sensor issue or a stretched abs harness?"

Hi macscac,

You can measure the "Wheel Speed Sensors" and the "Transmission Speed sensors" with a mega-ohm or volt multi-meter to verify their continuity/ACV output from the "ABS ECU" near the master cylinder.

If it turns out that you need to go further with an electrical investigation, msg me and I'll provide you the wiring diagram for the ABS system! The wheel speed sensors cost like $6 bucks each on ebay, transmission sensors are about the same!

The front and rear wheel speed sensors are one and the same; so there's a Left-side and a Right-side wheel sensor! 'Best to you',

rig

 

[macscac]

If they told you that I would take it to another dealer/shop. If you have one of those aftermarket HID kits like from xenon depot, etc. I rather doubt that this would interfere with a solenoid in the ABS system.

the only reason that i thought it might be possible is because i read a forum post where someone did get some interference from their zenon depots...
:/


i dunno.
its not the lights tho.. my system continues to be jacked even with the lights removed from the battery

 

[macscac]

Hi macscac,

You can measure the "Wheel Speed Sensors" and the "Transmission Speed sensors" with a mega-ohm or volt multi-meter to verify their continuity/ACV output from the "ABS ECU" near the master cylinder.

If it turns out that you need to go further with an electrical investigation, msg me and I'll provide you the wiring diagram for the ABS system! The wheel speed sensors cost like $6 bucks each on ebay, transmission sensors are about the same!

The front and rear wheel speed sensors are one and the same; so there's a Left-side and a Right-side wheel sensor! 'Best to you',


rig

so i am voltage meter stupid.
how am i to best resolve if its the sensor?
assuming no visual damage on them then remove each one and then do what?

Thank you!

 

[Dillusion]

Set to ohms and read across the sensor with the out disconnected.

 

[macscac]

the 'out' is the side that plugs in near the rotor?

what should the display on the voltage meter if its good/bad ?

should the truck be off or accessory mode or running?

 

[Dillusion]

the 'out' is the side that plugs in near the rotor?

what should the display on the voltage meter if its good/bad ?

should the truck be off or accessory mode or running?

Unplug the connector and read the side going to the sensor.

Not sure never had to check mine.

Truck should be off.

 

[macscac]

So after crawling under the truck, the speed sensors are in good physical condition. they are all plugged in properly and no apparent damage so i just need someone's guidance on how to properly voltage test them.
thank you!

 

[Deep_palancar]

So after crawling under the truck, the speed sensors are in good physical condition. they are all plugged in properly and no apparent damage so i just need someone's guidance on how to properly voltage test them.
thank you!

There are plenty internet resources showing how to test a speed sensor with a multi-meter, GTS. However, all that you will learn from a multi-meter is that the sensors are functioning. Since your problem is intermittent the chances of catching it are slim to nil. If you had an actual failed sensor then there would be a trouble code pointing to the specific sensor that is not pulsing the signal.

There are methods to diagnose the sensor's function, but to do it you'd have to have a recording oscilloscope AND be able to repeat the symptom at will. Based on your initial question, I don't see that as an option for you.

Throwing $1000 parts at it could get expensive quickly. You need to find someone who has diagnostic interest and ability. Sadly, the dealership probably does not have anyone with ability beyond reading codes and replacing parts. There may be freeze frame data that can provides some clues, having the actual codes would also help.

I don't have an answer for you because there is not one without some involved diagnostics.......

Since there is no specific speed sensor code you are probably wasting your time with meter testing sensors.

Have you done anything that could have stressed the wires ?? You could meter test the harnesses while flexing and moving things around.

 

[macscac]

There are plenty internet resources showing how to test a speed sensor with a multi-meter, GTS. However, all that you will learn from a multi-meter is that the sensors are functioning. Since your problem is intermittent the chances of catching it are slim to nil. If you had an actual failed sensor then there would be a trouble code pointing to the specific sensor that is not pulsing the signal.

There are methods to diagnose the sensor's function, but to do it you'd have to have a recording oscilloscope AND be able to repeat the symptom at will. Based on your initial question, I don't see that as an option for you.

Throwing $1000 parts at it could get expensive quickly. You need to find someone who has diagnostic interest and ability. Sadly, the dealership probably does not have anyone with ability beyond reading codes and replacing parts. There may be freeze frame data that can provides some clues, having the actual codes would also help.

I don't have an answer for you because there is not one without some involved diagnostics.......

Since there is no specific speed sensor code you are probably wasting your time with meter testing sensors.

Have you done anything that could have stressed the wires ?? You could meter test the harnesses while flexing and moving things around.

thanks for the reply.
yes, i have done a lot that could have stressed the wires. all offroad and no way of knowing what or when but, again, all the sensors look to be intact.

lol i wish i could just test a new solenoid to see if that actually was the problem

 

[Axix23]

With it being like a brand new car (2018), is it not covered under warranty?
How is your aftermarket lighting wired up? Photos?

 

[macscac]

With it being like a brand new car (2018), is it not covered under warranty?

How is your aftermarket lighting wired up? Photos?

44k miles when I posted. Close to 50k now. It’s all on me
my lighting is wired across the top front grill and up the driver side of the engine bay


Sent from my iPhone using Tapatalk

 

[rigtec]

so i am voltage meter stupid.
how am i to best resolve if its the sensor?
assuming no visual damage on them then remove each one and then do what?

Thank you!

Hi macscac,

It's okay to learn new stuff on this site; after all, that's all I do on here! And I'm new to our speed sensors too cause I just resolved a serious problem with my instrument cluster (completely) failing recently e.g., Every "Un-related" warning light on all at once!

So I knew that it wasn't triggered by a sensor or a particular system! And, I lost my "Speed-o-meter" & "Tach-o-meter" during this calamity as well! I did, however, measure the speed sensors though, just to Prove or dis-prove them.

Turned out to be the truck needed a "Zero Point Steering Calibration" & "YAW Rate Acceleration Sensor Calibration"! Once I did that, the Cluster lights all went out, and the speed-o-meter and Tach came back!

Getting back to you... you can take an ohm measurement (in Mega-ohm scale; very high resistance). They'll be a "M" appearing on the scale (not a "K" as in kilo-ohms). The Driver-side sensors will look like 0.349, or somewhere relative to that; no exact number because I measured from the "Skid Control ECU (to test the cables as well), near the master cylinder, so the front and rear cables add to the total resistance!

The Passenger side sensors seem to have a lower resistance (directly at the sensor terminals); most likely to compensate, due to the much longer cables involved on that side: I bought two new ones' so I also measured from the terminals on those! The Passenger-side sensor readings were more like 3.49 Mega-ohms!

I'm leaving the "Anti-lock brake circuit diagrams" here so you can test the sensors from under the hood at the "Skid-ECU" on the master cylinder so you can test the wiring AND the sensors at the same time!:

I'm sorry about the poor clarity of these diagrams... they are very clear on the original pages, and on-line. The top two are the first & second pages. The one on the bottom is the third page.

I don't know what's going on with our photo albums here on forum; there was a button for adding photos to the albums for the 1'st two, but the "Choose Image" button disappeared on the third so I had to resort to "Photo-Bucket" to upload the third page!

I did trace the sensor wires in different colors when I was working on my truck because it looked like rain once I got started, and the wind was blowing my papers across the parking lot, so I was trying to make the visual work a lil' easier!

If you run into trouble, hit me with a P.M. or a "Mention" and I'll try to help! 'Best to you',

rig

 

[Texas_Ranger]

My '01 had a master cylinder go out. All the lights go crazy and this annoying constant beep sounds, which you can't turn off. I found a used one for $400 and all was good after that. I had no warning before it went out besides my abs activating on minor bumps or quick stops, if that was related.