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2006 chevy trailblazer_ls_ext
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Hi, This is my first post although I am an old member of TrailVoy Community. I got so many good advices and got solved my problems with already posted solutions. Thanks to all the helping people here. Now I am facing a problem and could not find the solution.
I was driving my TB Ext 2006 at night and could not see a bump on the road and did not reduce my speed (I was almost at 40 miles per hour speed). After having a shock, 3 warning lights turned ON continuously as shown in the picture below. These are ABS, Traction control and repair Traction control. Any suggestion to solve this problem?
Thanks in advance.

TBproblem.jpeg
 

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2002 chevy trailblazer_lt
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677 Posts
Underneath the truck in the area of the drivers seat is the EBCM (Electronic Brake Control Module). Have a look to see if something like wiring maybe got damaged by some debris under there? What sort of bump was this? I once ran over a big rigs tire carcass at 60 mph in the dark! Just glad the wheel wasn't still in it!
 

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2004 chevy trailblazer_lt
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628 Posts
Also check the wiring to ABS sensors on the front and rear wheels to make sure they are intact and still plugged into the connectors they are supposed to go in.
 

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2003 chevy trailblazer_ltz
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160 Posts
Connect a REAL scan tool, find out what's making the ABS/Traction Control computer unhappy. Otherwise, you'll waste time, money, effort, and enthusiasm throwing a bunch of parts at the problem and MAYBE stumbling onto the solution by accident.
 

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2002 chevy trailblazer_lt
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Connect a REAL scan tool
For the record... A $12 bluetooth elm clone CAN pull all codes from ALL modules of these vehicles before the 2008 implementation of CANBUS. It just takes a little research and the right APP (android).
 

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2003 chevy trailblazer_ltz
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For the record... A $12 bluetooth elm clone CAN pull all codes from ALL modules of these vehicles before the 2008 implementation of CANBUS. It just takes a little research and the right APP (android).
When did I say anything about "CODES"? Sure, codes can be useful. The data stream is ESSENTIAL, and a piece-of-crap code reader doesn't give you access to the data stream.

Which is EXACTLY WHY I SPECIFIED A "REAL" SCAN TOOL, not a shiity "code reader". Code-readers are consumer-grade garbage.
 

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2003 chevy trailblazer_ltz
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I can "read" that, but I can't tell you what it means. I've never seen the data stream formatted like that. It seems very...unhelpful and difficult. I have no idea how to translate that into something useful. How would you pick out throttle-position sensor position from that screen? How do you find vehicle speed? Nope, I got NO idea.

My scan tool is ancient--probably older than most folks reading this forum. I can only graph two sets of sensor data at a time. Newer scan tools can graph four or more at a time. This example--direct read-out of MAP sensor, compared to direct read-out of O2 sensor cross-counts; formatted in a graph giving a short "history" of those values. You can see where I snapped the throttle open (vacuum plummets) and at the same time, O2 cross-counts goes to "0" before eventually recovering. (Maximum value is 23.) I can't get the photo to post, so here's the link to it.

If I only care about "instantaneous" values, I can see four dot-matrix text-and-numbers lines of the data stream--potentially eight items without scrolling. Of course, I have to scroll to see everything included on my Trailblazer. Again, newer scan tools have bigger screens that can show more info at once.

The data, by line, provided by my "Scanner" when connected to an '88 K1500 and reading engine info, is

RPM, O2 mv, Integrator number
Open/Closed loop, Rich/Lean
TPS voltage, Block Learn number
IAC counts, O2 crosscounts
Coolant Temp, Prom ID
MAP "hg, MAP Volts
ESC counter, Knock Y/N
A/F Learned Y/N, Battery Volts
Batt volts High Y/N, Batt volts low Y/N
AIR diverter solenoid, AIR switch solenoid port/converter
Vehicle speed, High Gear Y/N
TCC Command Y/N, TCC apply circuit active Y/N
P/N switch (In gear or in neutral), A/C requested

I can see four of those lines at a time, getting the rest requires scrolling. OR I can select any two of these items, and graph them.

But that's only the stuff I get from a certain OBD-I vehicle, an OBD-II computer gives more info, and of course the items change when it's set up to communicate with ABS, or Air bags, or the Instrument Cluster, or Transmission, or whatever..

In addition, in the photo, there's four LED lights. The two on the left are lit up. The way my scan tool is set up, the first one indicates closed-loop operation, the second one indicates "rich" mixture. The third is torque converter clutch engaged (it's not lit because the vehicle isn't moving when I took the photo) and the fourth indicates knock-sensor activity (detonation). Again, that one isn't lit because the vehicle is at idle, in neutral. Those LED lights are programmable, based on menu items, so I could set #3 light to be the closed-loop indicator, or I could change them all to signify something else.
 

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2002 chevy trailblazer_lt
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never seen the data stream formatted like that.
That is the class 2 serial data in its native form. What is seen in that picture is the very moment the key has been turned to the crank position. The PCM is reporting a status to vehicle security, the BCM acknowledges that message, the BCM also reports a vehicle security status, the BCM then reports the status of network control, indicating the key has been turned to the crank position, etc. In between all that the PCM reports the value of the Oil Life Monitor, the IPC reports the status of several indicator lights, among which are the high beam indicator and the security light. Everything seen in that image happened in just under one half second.
 

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2003 chevy trailblazer_ltz
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Yep, it all happens fast. Older computers didn't update as quickly as newer computers; nor did they operate with so many different bits of information.

But again, which line tells you the MAP sensor value? How are you going to pick that out as a problem during a test-drive? What indicates closed-loop operation? I know right away if the vehicle falls out of closed-loop; the LED light goes out, and the text display changes from "Closed" to "Open". I don't have any idea how to translate the info on your screen to something helpful in real-time diagnosis.
 

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2002 chevy trailblazer_lt
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which line tells you the MAP sensor value?

Well the MAP isn't broadcast on the serial data line, you ask for that with a PID (paramter ID). In the case of the MAP sensor you can request either the OBD standard mode 01 PID 0B or in the 4.2 ask for extended mode 22, PID 1142.
Cumbersome in a serial terminal. For data gathering and review I use the bluetooth obd adapter and the android app Car Scanner. It records the PID data and you can choose what to review later on graphs. You can also watch it live if you wish. Here is a graph with the VVT cam angles, actual, desired, and variance.

Screenshot_20200813-201018.png



Torque Pro is another highly popular App for use with inexpensive OBD adapters. Here is my Transmission page where monitor all manner of PID data including a custom one I made for detecting any clutch pack slippage. That displays the overall gear ratio through the transmission.

Screenshot_20200911-125456.png



The only real difference between the $12 obd adapter and expensive scantools is the software and the smartphone software has gotten pretty damn good.

I had an issue on my Yukon similar to this threads issue except I didn't have the warning lights but the cruise control would cut off. I used my little obd adapter and pulled up codes for the EBCM. Told me I was losing the right front wheel speed sensor. I was on a long drive and didn't feel like stopping so I just cleared the code from the EBCM. I only cleared the EBCM codes, did not affect other modules so emissions readyness was not affected. Had to do this several times, noticed it happened when I hit rough road. When I finally got to checking it out found the lead to the sensor had come detached from a securing point allowing the lead to rub against the wheel rim amd wear through. Resecured it and layered it up with liquid electrical tape. That was maybe 8000 miles ago.
 

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Hi, This is my first post although I am an old member of TrailVoy Community. I got so many good advices and got solved my problems with already posted solutions. Thanks to all the helping people here. Now I am facing a problem and could not find the solution.
I was driving my TB Ext 2006 at night and could not see a bump on the road and did not reduce my speed (I was almost at 40 miles per hour speed). After having a shock, 3 warning lights turned ON continuously as shown in the picture below. These are ABS, Traction control and repair Traction control. Any suggestion to solve this problem?
Thanks in advance.

View attachment 55792
Before you read any of the below:
Do as stated by Chem Man:
MAKE SURE ALL 4 OF YOUR WHEEL SPEED SENSORS ARE ACTUALLY CONNECTED. THEY CAN COME LOSE OVER TIME OR OVER BUMPS.

Plug in a scan tool and determine which of your 4 Wheel speed sensors is causing the lights to come on. If it was any other component you would have only the stabilitrack lights and no ABS light. If you do not have a scan tool or ABS capable code reader, I can recommend cleaning the front wheel speed sensors, they seem to cause the most issues.

If that doesn't fix it, you can try replacing the sensors. The sensors use a tone ring on the bearing and a magnet on the sensor to generate a basic a/c signal, over time the magnet can collect material that interferes with it's ability to function and the pcm will detect a difference in the two readings that it determines is abnormal given the current driving situation. (Ie turning v.s. driving in a straight line) typically this difference is negligible but your truck has stablitrack, which works in tandem with the ABS module to keep your truck from spinning out or losing control, and requires precise readings from the wheel speed sensors.

Also in my experience although the abs light is on, the abs pump should still activate if you slam the brakes hard enough. I think the deactivation of the pump is dependent on the actual problem/ code that is tripped.

VERY IMPORTANT: if you decide to clean or replace any sensors, you need to soak PB Blaster and maybe use some minimal heat on the 5mm Allen screw. You will break both of them if they haven't been off recently and you skip straight to the wrenching. (Don't ask me how I know) if you break those screws and are not capable of drilling and tapping them out, you could end up needing a new wheel bearing.

RELATED TORQUE SPECS should you try this.
Wheel lug nuts: 103 ft-lbs

Brake Mounting bracket (2 beefy bolts) (Remove the bracket leaving the caliper assembly and slide pins attached.: 118 ft-lbs

If you decide to replace the sensors, you should try to leave the plastic clips on the car and reuse them, they can be very difficult to remove from the steering knuckle.

If you have trouble removing the rotor, our lovely engineers left holes in the rotor you can thread a bolt through to push them off of the hub.
 

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Hi, This is my first post although I am an old member of TrailVoy Community. I got so many good advices and got solved my problems with already posted solutions. Thanks to all the helping people here. Now I am facing a problem and could not find the solution.
I was driving my TB Ext 2006 at night and could not see a bump on the road and did not reduce my speed (I was almost at 40 miles per hour speed). After having a shock, 3 warning lights turned ON continuously as shown in the picture below. These are ABS, Traction control and repair Traction control. Any suggestion to solve this problem?
Thanks in advance.

View attachment 55792
Sounds like you took out your speed sensor when you got the big hole in the road it's com
Hi, This is my first post although I am an old member of TrailVoy Community. I got so many good advices and got solved my problems with already posted solutions. Thanks to all the helping people here. Now I am facing a problem and could not find the solution.
I was driving my TB Ext 2006 at night and could not see a bump on the road and did not reduce my speed (I was almost at 40 miles per hour speed). After having a shock, 3 warning lights turned ON continuously as shown in the picture below. These are ABS, Traction control and repair Traction control. Any suggestion to solve this problem?
Thanks in advance.

View attachment 55792
Sounds like you took speed sensor when you hit the big hole the road it very commen
 

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Hi, This is my first post although I am an old member of TrailVoy Community. I got so many good advices and got solved my problems with already posted solutions. Thanks to all the helping people here. Now I am facing a problem and could not find the solution.
I was driving my TB Ext 2006 at night and could not see a bump on the road and did not reduce my speed (I was almost at 40 miles per hour speed). After having a shock, 3 warning lights turned ON continuously as shown in the picture below. These are ABS, Traction control and repair Traction control. Any suggestion to solve this problem?
Thanks in advance.

View attachment 55792
Check the abs cord on the hub bearing. It my have brook off or just came off.
 

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2004 chevy trailblazer_lt
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Chances are it is not unseated fuse(s) as a result of hitting that pot hole/bump, but I would check there first before turning wrenches.
 

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[QUOTE = "shb, publicación: 1616658, miembro: 79384"]
Hola, Esta es mi primera publicación aunque soy un antiguo miembro de la Comunidad TrailVoy. Recibí tantos buenos consejos y resolví mis problemas con soluciones ya publicadas. Gracias a todas las personas que ayudaron aquí. Ahora estoy enfrentando un problema y no pude encontrar la solución.
Conducía mi TB Ext 2006 de noche y no podía ver un bache en la carretera y no reduje mi velocidad (estaba a casi 40 millas por hora). Después de sufrir una descarga, 3 luces de advertencia se encienden continuamente como se muestra en la siguiente imagen. Estos son ABS, control de tracción y reparación de control de tracción. ¿Alguna sugerencia para solucionar este problema?
Gracias por adelantado.

View attachment 55792
[/CITAR]
Hola a todos, la mayoría de estos problemas se resuelven desconectando la batería por unos 10 minutos, esto hace que la computadora se reinicie y si el problema no es mayor puede haber solución, he solucionado muchos de estos "fallos" con este procedimiento.
Déjame saber si mi sugerencia te ayudó.

[email protected]

Salinas Ecuador
 

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2007 Trailblazer LT
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Had the same issue for the past few months and then the front bearing starting making a fuss. Swapped it out and all three lights went out. I think Ock's explanation of why all THREE lights are on is correct.
 

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[QUOTE = "shb, publicación: 1616658, miembro: 79384"]
Hola, Esta es mi primera publicación aunque soy un antiguo miembro de la Comunidad TrailVoy. Recibí tantos buenos consejos y resolví mis problemas con soluciones ya publicadas. Gracias a todas las personas que ayudaron aquí. Ahora estoy enfrentando un problema y no pude encontrar la solución.
Conducía mi TB Ext 2006 de noche y no podía ver un bache en la carretera y no reduje mi velocidad (estaba a casi 40 millas por hora). Después de sufrir una descarga, 3 luces de advertencia se encienden continuamente como se muestra en la siguiente imagen. Estos son ABS, control de tracción y reparación de control de tracción. ¿Alguna sugerencia para solucionar este problema?
Gracias por adelantado.

View attachment 55792
[/CITAR]
Hola a todos, la mayoría de estos problemas se resuelven desconectando la batería por unos 10 minutos, esto hace que la computadora se reinicie y si el problema no es mayor puede haber solución, he solucionado muchos de estos "fallos" con este procedimiento.
Déjame saber si mi sugerencia te ayudó.

[email protected]

Salinas Ecuador
No es una buena idea utilizar esa técnica en este momento. El problema es que hay muchos módulos que tendrán que pasar por pruebas y 'reajustes' (?) una vez que se desconecte la batería.

Los pequeños engranajes dentro de algunos de los motores de calefacción y aire acondicionado pueden romperse porque son viejos y frágiles.

Es una mejor idea esperar para usar esa técnica hasta que se intenten todos los demás remedios.

¿Por qué digo esto? Es una experiencia y es una experiencia cara.
 
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