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2002 chevy trailblazer_lt
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Discussion Starter · #1 ·
I have a 2002 trailblazer that has Rough idle, late shift, and lack of power it has the 4.2 in it. Any one have any ideas on where to look. I just go this trailblazer and am not sure where to start. It does not push any codes. I suspected a vacuum leak but could not find any.
 

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2002 chevy trailblazer_lt
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Discussion Starter · #3 ·
98 k miles. The service engine and service 4 wheel drive lights came on yesterday. I don't have a code reader. Are there any tricks to get the codes without or do I need to get a code reader?

Also the guy I bought it from hit a speed bump hard and the power steering quit working. He said it bottomed out but I don't see any crushed lines and fluid level are good. He said it lost power steering about 5 minutes after he bottomed it out.
 

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2004 gmc
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There are no substitutes for a code reader. You need to own one, know or pay someone with one, or some parts stores (outside a few states) will read them for you, hoping you'll buy the parts there.

Sounds like the previous owner had the codes cleared, then sneakily sold you the car before they came back to bite you. No mechanics inspection first, I take it?

There may be many other hidden things wrong that the seller concealed. Since you must have saved a TON of money buying in this unknown but broken condition, I think it's time to consult a professional, not a remote Internet forum who can't touch and feel your vehicle.
 

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Discussion Starter · #5 ·
Actually I purchased it for $800 because it needs a front clip and he thought the transmission was bad. I don't think it is the transmission is bad. I think it has a fuel management control system problem. I am trying to get it to run right before I rebuild the body. (Radiator support, Hood, Fender, Grille, Front Frame back to the sway bar, Inner Fender, Etc) It needs a lot of work but it is an LT with the leather interior and other than the wreck and this issue it is in real good shape. I am giving it to my wife as a birthday present. I know some of the new cars have a way to get you codes from the on-star systems. But if that is not the case with this one I now have a good excuse to buy the code reader that I have wanted for about 5 years now. I usually fix up pre-obd2 cars. This is the first time I have ever worked on a drive by wire system. But I have been working on cars for over 20 years.
 

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2004 gmc
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Any more clues you're going to conceal until I ask more questions? :rolleyes:

First it's lack of power. :undecided Then the error lights come on and it's a power steering failure from a speed bump. :confused: Lastly it sounds like the goof dropped it off a loading dock onto its nose. :eek:

Seriously, you could have broken sensor wires all through the harness if you have to rebuild the front end. Besides the code reader, you might want to buy the factory manual (Helm Inc.). This vehicle is intensely electronic in nature, with over a dozen distributed modules, and the front suspension especially has issues that you might need to be fixing as you get into the frame work.
 

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Discussion Starter · #7 ·
Lack of power Late shift and poor idle just like the title says. The power steering issue is a side note and not that important right now. He did not drop it off a loading dock he ran into a guard rail trying to avoid another idiot driver that cut into his lane. I have checked the wiring harness. That was the first thing I did. Also this problem did not happen from the wreck. It happened a year later. He has been driving it for quite some time wrecked and when this issue showed up he decided it was time to replace it. I know cars and I know the electrical systems quite well. I posted on this forum because sometimes these problems are common and some-one has fixed it and knows the answer, which save me time. I was under the impression that this is what these forums were intended for. I am new to this forum but I am not new to forums. These symptoms point to a vacuum leak, bad sensor or computer issue. The power steering is not controlled by the computer so I am not too worried about that it is probably a simple mechanical fix. I have never had to use a OBD2 Reader to fix any problem that I have run across. I have fixed some cars that are 96 and newer which is when OBD2 was standardized in the automotive industry. I did not mention that it was wrecked because it is irrelevant to the problem that I am trying to solve. The Suspension is not damaged I have already put it onto a frame rack and done all of the measurement. The Nose took the hit just like it is supposed to. The Trailblazer deflected to the right and there was no damage to the firewall, The inner fender and radiator support needs replace due to damage on the left outer area where the fender mounts. The top of the left side is pushed back about 1/2 inch and the replacement fender will not line up with out fixing this. The front perch for the radiator is pushed back a little and it twisted the front frame section on that side. I can probably bend it back into place but I am not sure that it will line up right so I am going to replace the front frame section from the rear of the sway bar forward.
 

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2003 chevy trailblazer_ls
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Lack of power Late shift and poor idle just like the title says. The power steering issue is a side note and not that important right now. He did not drop it off a loading dock he ran into a guard rail trying to avoid another idiot driver that cut into his lane. I have checked the wiring harness. That was the first thing I did. Also this problem did not happen from the wreck. It happened a year later. He has been driving it for quite some time wrecked and when this issue showed up he decided it was time to replace it. I know cars and I know the electrical systems quite well. I posted on this forum because sometimes these problems are common and some-one has fixed it and knows the answer, which save me time. I was under the impression that this is what these forums were intended for. I am new to this forum but I am not new to forums. These symptoms point to a vacuum leak, bad sensor or computer issue. The power steering is not controlled by the computer so I am not too worried about that it is probably a simple mechanical fix. I have never had to use a OBD2 Reader to fix any problem that I have run across. I have fixed some cars that are 96 and newer which is when OBD2 was standardized in the automotive industry. I did not mention that it was wrecked because it is irrelevant to the problem that I am trying to solve. The Suspension is not damaged I have already put it onto a frame rack and done all of the measurement. The Nose took the hit just like it is supposed to. The Trailblazer deflected to the right and there was no damage to the firewall, The inner fender and radiator support needs replace due to damage on the left outer area where the fender mounts. The top of the left side is pushed back about 1/2 inch and the replacement fender will not line up with out fixing this. The front perch for the radiator is pushed back a little and it twisted the front frame section on that side. I can probably bend it back into place but I am not sure that it will line up right so I am going to replace the front frame section from the rear of the sway bar forward.
You might want to go to the search button and type in: Lack of power or maybe poor idle, or maybe late shift and see what happens. Asking for somebody else to give you links to the problems might not work well. With a severe front end crash, wires, crimps, plugs, prongs, relays, etc might, and will over time, cause lots of problems. Code readers and units that will give you live data just might save you and us lots of time.
 

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Discussion Starter · #9 ·
I will post the codes when I get them. When I originally started this thread there were no codes. I plan on getting a code reader in the next day or 2.

On my initial inspection I was expecting to find a damaged hose or broken harness.

I have checked the harness out really close and found nothing more than a wire to the headlight broken. I Cleaned the engine compartment and checked all of the connections on the motor. And found no problems. Nothing loose. No signs of damage anywhere on the harness or the connections.

I searched for these symptoms individually and did not find much that fit all three symptoms. All three symptoms showed up at the same time.

I agree that in a severe accident there can be problems that don't show up for months. But this accident is not a severe as is sounds. The damage is relatively minor, It is a lot of damage because of where it hit. It was more of a side swipe than a head on. There was not enough of an impact to deploy the airbags. It is minor enough that the front of the headlight on that side is not broken, only the mounts are. The Upper fender rail has very small bow in it that is just enough that the bolts for the replacement fender may not line up. The damage on the radiator support is also so minor that it may be re-usable.

I think people are getting the impression that it was a head on collision. That is not the case.

Also If I would have had service lights when I first looked at it. I would have not posted this at all. The service engine light and the service 4 wheel drive light came one at the same time. After running in park for about 10 minutes. While I was checking for leaks. And watching the engine temp.

I will post the codes that I get out of it.

Thanks
 

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2003 chevy trailblazer_ls
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I bought the Equus 3160 because it will read ABS, pending codes, give snapshots and record live data (20 sec. I believe) Just reading codes can help but all the other stuff is neat. Did you unplug and replug every connector that you could find? Have you removed and cleaned the throttle body with the battery disconnected for at least 20 minutes?
 

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It can be anything from a bad thermostat to a pending misfire. Once you get the codes, post them up and it'll make it easier for all of us to help you out. Also, please take the time to fill out your user cp so we know what we're working with...thanks!!:thumbsup:
 

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Discussion Starter · #12 ·
Yes I did unplug and replug all of the connectors. I let it sit for about an hour and the codes where still there. I cleaned the throttle body it did not solve the problem. I checked out the Equus 3160 and it is cool but a little on the pricey side. I talked the Chevy dealer and the code read from your dash is a dodge feature. 3 quick turns of the key and it reports all of you codes.

I bought the Equus 3160 because it will read ABS, pending codes, give snapshots and record live data (20 sec. I believe) Just reading codes can help but all the other stuff is neat. Did you unplug and replug every connector that you could find? Have you removed and cleaned the throttle body with the battery disconnected for at least 20 minutes?
 

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Discussion Starter · #15 · (Edited)
Thats what 2 dodge owners and the mechanic at our local Chevy dealer told me. I have not seen it myself but I have heard it from several people now. On the older Chevy's you can use ajumper and count the flashes but that is OBD 1
 

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Confirmed here: http://www.allpar.com/fix/computer-codes.html

Chrysler, Dodge and Jeep 2002-2008. The code appears on the odometer after three ignition key blips.

Lucky bums.
Oops I misunderstood when he said " I talked the Chevy dealer and the code read from your dash is a dodge feature. 3 quick turns of the key and it reports all of you codes." I thought he meant our GM products did the same thing. Must have had a "gray" moment there or something! :)
But I did not realize that the newer Chrysler products still did that.
I will sleep better tonight now that I do! :D :D :D

:iagree:

I've done that on some of the old Dodge products, but I've never heard of GM doing that. Look at all the money we have wasted buying OBDII code readers!
 

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Discussion Starter · #18 · (Edited)
I finally got the codes read and I got one back it was P0300. Multiple engine misfire. Most of what I have read with this code has another code with it. So I am not sure what to think with that combine with the shifting issue. Also I noticed on the way to get the code read that the AC was reading 50 degrees outside temp. But it is 95 here. I don't think this is really relevant to the issue I am having but I am adding it just in case. Also the Check engine light comes on steady and after a couple of minutes it starts flashing. The Check 4-Wheel Drive light is on also. One more thing it get about 7 MPG and wreaks of gas.

I have cleaned the Throttle body. I am looking at plugs tonight. But if it is a coil pack which one will cause it to show multiple misfires and not show a specific cylinder.

FYI

If you go to read the codes and the code reader can not connect check your cigarette lighter fuse...
 

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I have a 2001 GMC Jimmy and that was giving out misfire codes for a good 5 months and it was shifting late, lacking power, and wreaking of gas. Then I was told it could have been drip valves ceasing and then one day the light went away and so did the symptoms. I know the Jimmy was the early and smaller version of an Envoy so I don't know if that helps or not?

It has almost the same engine as my 02 TB.
 

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I finally got the codes read and I got one back it was P0300. Multiple engine misfire. Most of what I have read with this code has another code with it. So I am not sure what to think with that combine with the shifting issue. Also I noticed on the way to get the code read that the AC was reading 50 degrees outside temp. But it is 95 here. I don't think this is really relevant to the issue I am having but I am adding it just in case. Also the Check engine light comes on steady and after a couple of minutes it starts flashing. The Check 4-Wheel Drive light is on also. One more thing it get about 7 MPG and wreaks of gas.

I have cleaned the Throttle body. I am looking at plugs tonight. But if it is a coil pack which one will cause it to show multiple misfires and not show a specific cylinder.

FYI

If you go to read the codes and the code reader can not connect check your cigarette lighter fuse...

you're close to the 100,000 mile mark anyway, so i say go ahead and do a tune-up (delco iridium plugs, air/fuel filters, etc). Also clean the throttle body and run a fuel injector in the tank (seafoam, techron, etc). :thumbsup:
 
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