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2003 chevy trailblazer_ltz
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Connect scan tool, look for "codes" and follow service manual procedure to resolve them.

Normally, I'd say to look at the data stream, but I bet in this case the codes will be enough.
 

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2004 chevy trailblazer_lt
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Welcome to the Forum!

Question 1 - Why did you change the throttle body?

Question 2 - Do you have an electronic fan clutch (wires going to it) or a thermostatic fan clutch (no wires going to it)?

If you intend on maintaining your TrailBlazer, then you cannot afford not to have a code reader/scanner. It can save you more money than you can image! For around $25.00 you can get a code reader setup for an Android device that is extremely powerful and worth every penny. Purchase this Bluetooth OBDII dongle from Amazon and then download the Torque Pro app for $5.00 from the Google play store.


Good Luck!
 

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Discussion Starter · #5 ·
Well I was researching it and the most common cause is the throttle position sensor which is built into the throttle body and 2 no wires going to the fan
 

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2004 chevy trailblazer_lt
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Research what exactly? You have not said why you replaced a $200 part. What diagnostics did you perform other than researching some problem you have yet to disclose. I can guess, but I do not like my odds.
 

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Discussion Starter · #7 ·
I am a diy mechanic I work all kinds of cars but this has me stumped I dislike the computerized vehicles cause 1 thing can be wrong and throw 5 diff codes even the Chevy dealer and other mechanic shops I talked to the throttle body was the most common then they also say could be the gas pedal position sensor then someone told me today if I replaced the throttle body need a 3000 scan tool to do a re-learn on it I would rather have a 98 to 01 dodge over anything else
 

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2004 chevy trailblazer_lt
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Fine, But you still have not said what problem you were having that allegedly pointed you in the direction of replacing the throttle body, and I do not care what the Chevy dealer or other mechanics said. You are not talking to them now. You are talking to at least me on this forum, and we (myself and the forum) needs to know what the problem was that you were led to believe the solution was to replace the throttle body.

Remember, we are impartial here. In order to assist you, we sometimes have to ask questions, and this is one of those times, so please answer the questions - 1, What problem were you trying to solve and 2, does your TrailBlazer have an electronic or a thermostatic clutch? VERY IMPORTANT QUESTIONS only you can answer.

Also whoever told you that you need a $3000 scan tool is full of dung!!!!!!
 

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2004 chevy trailblazer_lt
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Thank you!!!! Now we can begin to help you.

First, you are going to need a code reader/live data scanner if you are serious about maintaining your TrailBlazer or other post 1996 model vehicle. Also, you will need a digital multimeter (DMM) in case you do not have one, and instead of a test light, get a Logic Probe (they are about $10.00 at Harbor Freight) as they will not kill an electronic module like a test light can.

OK, Reduced Engine Power is a very common occurrence on TrailBlazers with electronic fan clutches. Why? Because the fan clutch and the throttle body both share the same 5 Volt reference voltage, and if the fan clutch goes out, it pulls down the 5 V reference voltage to zero, and the TrailBlazer goes into "limp mode" in order to protect the engine.

Now, there are a couple of diagnostic checks to do before condemning either the fan clutch or the throttle body. One, look over the wiring bundles that go to the fan clutch and the throttle body. Make sure the connectors are seated properly. Look over the wires to make sure that the insulation has not rubbed away and that the wire or wires are not grounding out. Look over the wires and make sure none of them are broken. Follow the wire bundles back as far as you can and make sure none are rubbing against the engine block or other structure and grounding out. Verify that you are seeing 5 VDC at the connectors that plug into the fan clutch and the throttle body.

Now since you do not have any codes, it is not worth chasing any other potential problems with the throttle body.

As I said earlier, not having a decent code reader/live data scanner is a real impediment to you successfully maintaining your TrailBlazer and you cannot accurate diagnose the problem with out one. Heck you even need one to work on a 98 - 2001 Dodge, and don't kid yourself by thinking you do not.

Also, fan clutch failures are much more likely to happen than throttle body failures by a huge amount. The odds favor a bad fan clutch over a throttle body, but diagnose the problem first and save a lot of money in the long run.
 

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2004 chevy trailblazer_lt
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Double posting
 

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Discussion Starter · #12 ·
Thank you!!!! Now we can begin to help you.

First, you are going to need a code reader/live data scanner if you are serious about maintaining your TrailBlazer or other post 1996 model vehicle. Also, you will need a digital multimeter (DMM) in case you do not have one, and instead of a test light, get a Logic Probe (they are about $10.00 at Harbor Freight) as they will not kill an electronic module like a test light can.

OK, Reduced Engine Power is a very common occurrence on TrailBlazers with electronic fan clutches. Why? Because the fan clutch and the throttle body both share the same 5 Volt reference voltage, and if the fan clutch goes out, it pulls down the 5 V reference voltage to zero, and the TrailBlazer goes into "limp mode" in order to protect the engine.

Now, there are a couple of diagnostic checks to do before condemning either the fan clutch or the throttle body. One, look over the wiring bundles that go to the fan clutch and the throttle body. Make sure the connectors are seated properly. Look over the wires to make sure that the insulation has not rubbed away and that the wire or wires are not grounding out. Look over the wires and make sure none of them are broken. Follow the wire bundles back as far as you can and make sure none are rubbing against the engine block or other structure and grounding out. Verify that you are seeing 5 VDC at the connectors that plug into the fan clutch and the throttle body.

Now since you do not have any codes, it is not worth chasing any other potential problems with the throttle body.

As I said earlier, not having a decent code reader/live data scanner is a real impediment to you successfully maintaining your TrailBlazer and you cannot accurate diagnose the problem with out one. Heck you even need one to work on a 98 - 2001 Dodge, and don't kid yourself by thinking you do not.

Also, fan clutch failures are much more likely to happen than throttle body failures by a huge amount. The odds favor a bad fan clutch over a throttle body, but diagnose the problem first and save a lot of money in the long run.
Thank you!!!! Now we can begin to help you.

First, you are going to need a code reader/live data scanner if you are serious about maintaining your TrailBlazer or other post 1996 model vehicle. Also, you will need a digital multimeter (DMM) in case you do not have one, and instead of a test light, get a Logic Probe (they are about $10.00 at Harbor Freight) as they will not kill an electronic module like a test light can.

OK, Reduced Engine Power is a very common occurrence on TrailBlazers with electronic fan clutches. Why? Because the fan clutch and the throttle body both share the same 5 Volt reference voltage, and if the fan clutch goes out, it pulls down the 5 V reference voltage to zero, and the TrailBlazer goes into "limp mode" in order to protect the engine.

Now, there are a couple of diagnostic checks to do before condemning either the fan clutch or the throttle body. One, look over the wiring bundles that go to the fan clutch and the throttle body. Make sure the connectors are seated properly. Look over the wires to make sure that the insulation has not rubbed away and that the wire or wires are not grounding out. Look over the wires and make sure none of them are broken. Follow the wire bundles back as far as you can and make sure none are rubbing against the engine block or other structure and grounding out. Verify that you are seeing 5 VDC at the connectors that plug into the fan clutch and the throttle body.

Now since you do not have any codes, it is not worth chasing any other potential problems with the throttle body.

As I said earlier, not having a decent code reader/live data scanner is a real impediment to you successfully maintaining your TrailBlazer and you cannot accurate diagnose the problem with out one. Heck you even need one to work on a 98 - 2001 Dodge, and don't kid yourself by thinking you do not.

Also, fan clutch failures are much more likely to happen than throttle body failures by a huge amount. The odds favor a bad fan clutch over a throttle body, but diagnose the problem first and save a lot of money in the long run.
 

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Premium Member
2004 chevy trailblazer_lt
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Well, if you have an electronically controlled fan clutch and there are no wires going to it, then you have a problem. If you have a thermostatic fan clutch, there are no wires to it and it cannot be the problem.

If you indeed do have a thermostatic clutch, then the first question that needs to be asked by us on this forum is - what are the Diagnostic Trouble Codes. Without them it is like playing golf with a black ball in the dead of night with no lights to assist you.

Job one for you now is to determine what type of fan clutch is on your Trailblazer because it appears that for at least a time, the 2008s did come with an electronically controlled fan clutch before the factory switched to thermostatically controlled fan clutches.
 

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2003 chevy trailblazer_ls
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I am a diy mechanic I work all kinds of cars but this has me stumped I dislike the computerized vehicles cause 1 thing can be wrong and throw 5 diff codes even the Chevy dealer and other mechanic shops I talked to the throttle body was the most common then they also say could be the gas pedal position sensor then someone told me today if I replaced the throttle body need a 3000 scan tool to do a re-learn on it I would rather have a 98 to 01 dodge over anything else
godsmack: you just gave away that you have not a clue as to what you are doing. listen to chem-man, pay 25 bucks and get the dongle and 5 bucks for the torque pro. i did and fixed issues for a tenth the STUPID price. Thanks
 
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