How common are ecu failures on 01-02 t4r

[xspsi6]

How common are abs/vsc ecu failures on 01-02 t4r

My speedo in inop and I replaced the cluster with a known good one so only thing left in line is the ecu as per the factory service manual as the wheel speed sensors send a signal to the cluster head then to the ecu which converts it to speed if I understand correctly?

I think this may be the only thing left in line.

 

[Aelfwine]

Sorry, you're not being clear in what your issue is and what you're doing there. If I understand correctly your speedo is off? If it is then I have the same issue on my 02. I haven't done anything to troubleshoot it yet. First in line for me is changing speed sensors since I have ABS issues as well.

 

[TheDurk]

Actually, on the '01-'02 the four wheel sensors send their signals to the VSC ECU located under the far left side of the dash and then a single speed signal is sent from there to the speedo in the cluster. Just to be clear, the ECU involved is the VSC ECU. Normally when people say just ECU, they mean engine control unit, which is not involved here.

Be aware that '01-'02 are different from other years as speedo setup goes due to the VSC. There are also two speed sensors on the trans, which send their signals to the engine ECU, but I don't know if those can affect the speedo.

 

[Aelfwine]

My Garmin shows a difference of 5km/h. Considering that the GPS is more precise I'm actually going slower than my speedo is telling me.

 

[xspsi6]

Actually, on the '01-'02 the four wheel sensors send their signals to the VSC ECU located under the far left side of the dash and then a single speed signal is sent from there to the speedo in the cluster. Just to be clear, the ECU involved is the VSC ECU. Normally when people say just ECU, they mean engine control unit, which is not involved here.

Be aware that '01-'02 are different from other years as speedo setup goes due to the VSC. There are also two speed sensors on the trans, which send their signals to the engine ECU, but I don't know if those can affect the speedo.

Correct I should have been more specific I was referring to the abs/vsc ecu not the main ecu which is wher as I understand where my problem comes from as in no speedo or cruise and cel,abs,vsc,brake lights are all on

 

[TheDurk]

Correct I should have been more specific I was referring to the abs/vsc ecu not the main ecu which is wher as I understand where my problem comes from as in no speedo or cruise and cel,abs,vsc,brake lights are all on

So what are your DTC codes?

 

[xspsi6]

On the obd scanner just vehicle speed sensor po500 is there a way to pull the abs/vsc codes?

 

[Robb235]

My Garmin shows a difference of 5km/h. Considering that the GPS is more precise I'm actually going slower than my speedo is telling me.

Same here. So we really have more mileage on our vehicles than it states. :guitar3:

Not really. Even though your speedo is off, your odometer is pretty accurate.

Picture of my Garmin vs. odometer on a long trip.

 

[xspsi6]

The abs ecu /module is located on the master cylinder/pump correct?

 

[Aelfwine]

I think its under your dash, near the hole in the firewall where all the wires go through.

 

[xspsi6]

I was under the impression that is the efi ecu? There is a box on the bmc that looks like it could be an ecu of some sort.

In google searching this problem it seems to be semi common failure but nobody ever post back after it gets fixed.

 

[xspsi6]

Actually, on the '01-'02 the four wheel sensors send their signals to the VSC ECU located under the far left side of the dash and then a single speed signal is sent from there to the speedo in the cluster. Just to be clear, the ECU involved is the VSC ECU. Normally when people say just ECU, they mean engine control unit, which is not involved here.

Be aware that '01-'02 are different from other years as speedo setup goes due to the VSC. There are also two speed sensors on the trans, which send their signals to the engine ECU, but I don't know if those can affect the speedo.

I just re read this thread and my question was answered already in this post so today I will pull the ecu and open it up to look for leaking caps or damaged circuts etc etc

 

[Aelfwine]

I was under the impression that is the efi ecu? There is a box on the bmc that looks like it could be an ecu of some sort.



In google searching this problem it seems to be semi common failure but nobody ever post back after it gets fixed.

Anyway, thats where mine is located. It says right on it ABS/TRC/VSC. Make sure you're taking apart the right one before you do)))

 

[xspsi6]

Mine was on the lower drivers side foot well and I got it out and all looks fine visually but Thursday I have a co worker of my wife coming over with her 01 just like mine so I will swap hers in my truck to see if that were to take care of the problem and if so I priced a replacement at Toyota today and it was only 300ish our cost for a new one so I am hoping this does it!

 

[Aelfwine]

Interested in how it turns out. Let me know if it works, most people forget after they solve the problem!)))

 

[xspsi6]

Interested in how it turns out. Let me know if it works, most people forget after they solve the problem!)))

For sure I intend to so that it can help someone in the future.

 

[xspsi6]

She came over and turns out her truck was an 00 not an 01 like she thought

Back to the drawing board...