Fix for ABS, VSC TRAC, VSC OFF, & Brake lights remain on no CEL, or how to repair an ECU

[JOmega]

Much thanks to OP for this information. After parking my 2000LC for 6 months, I found this post and ordered a 10-pack of the updated part number recommended, got it to a local guy with circuit-board pro-skills, and . . . BAM! No more Christmas tree lights on the dash board! The specs and testing information were very helpful years after your post.

 

[FJRyder]

Much thanks to OP for this information. After parking my 2000LC for 6 months, I found this post and ordered a 10-pack of the updated part number recommended, got it to a local guy with circuit-board pro-skills, and . . . BAM! No more Christmas tree lights on the dash board! The specs and testing information were very helpful years after your post.

This is awesome! Glad to see that documenting this is helping so many people out!

 

[D1EZEL]

Count another one fixed from these great instructions, 2001 LX470, back on the road.

Thanks FJRyder

I used this video to assist in learning how to replace a component with a hot air solder station, I used the one FJRyder recommended.

 

[MiyamotoMusashi]

@FJRyder your inbox is full. I have an ECU that could use your touch.

 

[FJRyder]

@FJRyder your inbox is full. I have an ECU that could use your touch.

Thanks, just cleared out a few messages

 

[OEMGUY0720]

Thanks, just cleared out a few messages

Hey @FJRyder I sent you a dm Thanks!

 

[RcCola]

Hey @FJRyder You just saved me a bunch of money! Thank you so much for taking the time to share this repair.

 

[mstiebel]

I've been struggling with a brake issue for months and I'm wondering if it's the ABS ECU. The only xmas lights I'm getting are ABS, VSC TRAC, and VSC OFF.

I am able to pull techstream codes which are:

C1223 - ABS Control System Malfuntion
C1246 - Master Cylinder Pressure Sensor (The sensor and plunger have been replaced)
C1249 - Open Circuit in Stop Light Switch Circuit
C1340 - Open Circuit in Center Diff Lock Signal

I ran a zero point calibration and only the first two came back immediately. I haven't driven it today to see if anything else crops up.

I have pulled the ECU from the truck and tested the pin impedence across the X3 resonator. All circuits are open, which seems to disagree with the measurements listed at the top of the thread.

Is there any reason why a bad ABS ECU would throw the other three codes? Should I just pull the trigger on an ebay ECU? Thanks for you help!

 

[FJRyder]

I've been struggling with a brake issue for months and I'm wondering if it's the ABS ECU. The only xmas lights I'm getting are ABS, VSC TRAC, and VSC OFF.

I am able to pull techstream codes which are:

C1223 - ABS Control System Malfuntion
C1246 - Master Cylinder Pressure Sensor (The sensor and plunger have been replaced)
C1249 - Open Circuit in Stop Light Switch Circuit
C1340 - Open Circuit in Center Diff Lock Signal

I ran a zero point calibration and only the first two came back immediately. I haven't driven it today to see if anything else crops up.

I have pulled the ECU from the truck and tested the pin impedence across the X3 resonator. All circuits are open, which seems to disagree with the measurements listed at the top of the thread.

Is there any reason why a bad ABS ECU would throw the other three codes? Should I just pull the trigger on an ebay ECU? Thanks for you help!

If you are able to communicate with the ABS module at all, that eliminates this specific issue from the list as the bad resonator make communications impossible.

If you are measuring an open across all combinations of the terminals, this is likely due to the passivation coating used to prevent corrosion. You'll need to use needle probes to pierce through the sticky coating or scrape it away.

This post only addresses one component out of a thousand. It could be possible another component is causing this.
I would also inspect the wire harness as I have read issues of water intrusion due to a bad windshield replacement.

 

[Notion11]

Hi, I'm new to land cruiser platform and just got for pennies 100 series with bunch of thing to fix. Mainly frame is in good shape, motor cranks up and running like new, tranny shifts smooth without kicks. With having all those lights on dashboard as mentioned in this post - I've connected to techstream and saw * symbol in front of ABS/VSC/TRAC. Huuge thank you to @FJRyder for this troubleshooting and solution. Me holding multimeter 3rd time in hands - I've measured ceramic resonator (x3) resistance and set MM to 200k ohms and got following measurements:
R (gnd) + L = 166.7
R + L (gnd) = 94.2
C (gnd) + R = 08.2
C (gnd) + L = 157.2
Please help to understand those - I'd assume its bad since L+R is not in Millions Ohms or OL (open loop), correct?

 

[FJRyder]

Hi, I'm new to land cruiser platform and just got for pennies 100 series with bunch of thing to fix. Mainly frame is in good shape, motor cranks up and running like new, tranny shifts smooth without kicks. With having all those lights on dashboard as mentioned in this post - I've connected to techstream and saw * symbol in front of ABS/VSC/TRAC. Huuge thank you to @FJRyder for this troubleshooting and solution. Me holding multimeter 3rd time in hands - I've measured ceramic resonator (x3) resistance and set MM to 200k ohms and got following measurements:
R (gnd) + L = 166.7
R + L (gnd) = 94.2
C (gnd) + R = 08.2
C (gnd) + L = 157.2
Please help to understand those - I'd assume its bad since L+R is not in Millions Ohms or OL (open loop), correct?

Congrats on getting into the Hundy (100 series)! They are for the most part easy to work on and very reliable. I've owned my '02 LX470 for 20 years and I think it has at least another 20 years to go!

I'm glad that you found the thread helpful. From your description, it definitely sounds like the resonator is bad on your ABS module.

So with a manual ranging multimeter, your measurement will be dependent on the range setting you have selected.
When in the range within the K ohms, you will need to multiply the reading by 1000x.

So your reading become:
R(gnd) + L = 166.7k ohms
R + L(gnd) = 94.2k ohms
C(gnd) + R = 08.2k ohms
C(gnd) + L = 157.2k ohms

My guess is that your (gnd) indication is referring to the ground lead of the multimeter. Since resistance does not have polarity, this can be ignored. If you were measuring a diode or some other type of semiconductor, this would have importance. Since you are seeing a difference between R to L depending on the ground terminal, my guess is that this has something to do with the protective corrosion coating on the circuit preventing a good reading. Needle tip leads would help with this.

In any case, the resistance between either left or right pin to the center pin should be open or in the mega ohm (Mohm) range. You are measuring well below this which indicates that your resonator is in fact bad.

Hope this helps.

Here's a video I found that demonstrates using a manual ranging multimeter:

 

[Notion11]

Thank you a lot again @FJRyder! Wow, no wonder they call you guru I've put abs module back without doing any soldering, started the car - lights were gone. Started driving a car and immediately got VSC OFF and VSC TRAC lights (only those two) . Ordered part from Newark from link you provided, will take to my friend he can do soldering for me. Do you think I should measure other two resonators X1 and X2?

 

[FJRyder]

Thank you a lot again @FJRyder! Wow, no wonder they call you guru I've put abs module back without doing any soldering, started the car - lights were gone. Started driving a car and immediately got VSC OFF and VSC TRAC lights (only those two) . Ordered part from Newark from link you provided, will take to my friend he can do soldering for me. Do you think I should measure other two resonators X1 and X2?

Yeah I have seen some of these that are intermittent.

The other two (X1/X2) are crystal type oscillators. I've never seen one of these fail.
The one that fails (X3) is a ceramic resonator and the failure seems to have something to do with the packaging.