ABS & VSC Systems

[DAGEAR]

Hello,

I recently purchases an 02 Sequoia 4WD limited. I think there is something up with the ABS and or VSC systems.

ABS - ABS light does not light up when engine is started and the ABS does not appear to be operational since tires lock up on gravel with no familiar brake pulsation of ABS brakes.

VSC - With the vehicle in 4WD, I can't disable the VSC system.

Any thoughts on where the VSC & ABS ECU's are located?

Thoughts on how to troubleshoot.

Thanks

[nhparrot]

When you start the vehicle does the ABS warning light, VSC TRAC warning light, VSC OFF (TRAC OFF) indicator light, BRAKE warning light and SLIP indicator light goes on for approx. 3 seconds and then go out?

Are there any indicator lights stay on 3 seconds after starting?

[DAGEAR]

ABS, VSC, VSC lights never turn on either after starting or after 3 seconds.

Thinking that the wires to indicator lights may be unplugged?

[nhparrot]

With the Parking Brake applied does the BRAKE warning light come on?

[DAGEAR]

No, Brake light never comes on.

Airbag and check engine lights do light upon starting then turn off.

[nhparrot]

Try this

(a) Disconnect the connector from the brake fluid warning
switch
(b) Release the parking brake pedal.
(c) Connect the terminals on the harness side of the level
Warning switch connector.
(d) Start the engine, check that the warning light lights up.

If warning light does not light up, test the bulb or wire harness at the combination meter.

[DAGEAR]

Glenn just to confirm process and location.

Is connector in step A, located on master cylinder.

Where is combination meter located?

[nhparrot]

Originally Posted by DAGEAR

Glenn just to confirm process and location.

Is connector in step A, located on master cylinder.

Where is combination meter located?

step A is the 2 wire connector on the Brake Fluid Reservior.

The Combination Meter is Toyota-speak for the Gauge Cluster.

[DAGEAR]

Glenn,

A few more q's before I go try this.

1. I have had the access panel underneath the steering wheel removed, is the combination meter accessible from this point or is more disassembly required?

2. Where are the VSC and ABS ECU's located?

Thanks for all your help.

[nhparrot]

1- The Cluster finish panel comes out after removing 2 screws. There are 4 screws holding the combination meter.

2 - What you are looking for is the Skid Control ECU attached to the ABS & VSC Actuator on the passenger side of the engine compartment.

Just a word of note, unless there is something obviously wrong or something simple like burned out bulbs, you will need the repair manual, the electrical wiring diagrams, and some experience in automotive electrical systems to diagnose and repair.

[DAGEAR]

Glenn,

After researching which bulbs work and which ones don't this is what I have figured out.

-Door Ajar lights & Brake do not work
-None of the ABS, VSC, VSC off, slippery work
-Security, Check Engine, Do.

do you have access to Combination meter and wiring diagrams for 2002 Sequoia. I think I found another thread for the 2003 combination meter.

My background is hobbyist mechanic, design electrical circuits for a living. I was hoping to locate something obvious as you stated. Will keep the forum up to date as to what I find to be the cause.

Even though the ABS & VSC lights do not function, wouldn't a malfunction of either the ABS or VSC systems show up on a scan at a Toyota dealer?

[DAGEAR]

Glen

Unfortunately found the obvious, someone has REMOVED all the bulbs that are not working.

I am a little irritated at myself, for purchasing the vehicle, from Auction House, but "BUYER BEWARE". I plan to check tomorrow as to what my avenues of recourse are since I did have the understanding from the seller that all systems were functioning. Unfortunately, I have already spent $600 on fluid flushes, rear brake pads.

I will keep you informed. Bright side I can have the combination meter removed in under 5 minutes :0).

What does a subscription cost?

[nhparrot]

Originally Posted by DAGEAR

Glen

Unfortunately found the obvious, someone has REMOVED all the bulbs that are not working.

I am a little irritated at myself, for purchasing the vehicle, from Auction House, but "BUYER BEWARE". I plan to check tomorrow as to what my avenues of recourse are since I did have the understanding from the seller that all systems were functioning. Unfortunately, I have already spent $600 on fluid flushes, rear brake pads.

I will keep you informed. Bright side I can have the combination meter removed in under 5 minutes :0).

What does a subscription cost?

Replace the bulbs, they may have been removed to hide an issue. If you are interested in becoming a TS.com subscriber see > Subscriptions

[DAGEAR]

Glenn,

I have read the member benefits, just wanted to checkout one item.

As a member would I have access to the Toyota factory service manuals? example, instructions/illustrations on replacing the skid control / ABS ECU?

Next do you know of a good source for this ECU?

Plan to replace the bulbs today.

[DAGEAR]

Glenn,

Does the on board computer (the one that is scanned) keep a scan history, i.e. last time & date that it was scanned?

Trying to determine who last scanned this vehicle as an attempt to determine who removed the bulbs.