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2005 chevy trailblazer_ls
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Discussion Starter #1
Just as the title states. I recently experienced a period of rough, erratic idle and a CEL. Well, after calling the local dealership, I got a rough estimate on the price of a fix. $99 for diagnosis, $200+ for parts and $200 for labor. That was the low end, and even if they could find and fix the problem.:eek:

After finding this forum and reading up a little...I decided to look at the throttle body, and the sensors I could find (cam actuator was clean and cam position) and possibly clean them. I put everything back together and fired it up. Same problem.
After that, I proceeded to talk to a few local mechanics and get other opinions.

About 3 hours later and no luck yet, I went to the local Autozone to get the CEL code. The code thrown was P0017. Cam/Crank position sensor. So I purchased a $20 Crank Position Sensor. Its located on the intake side of the block ,towards the rear, slightly above the driveshaft. I can't seem to find pics anywhere on the net that show exactly where it is. But I found it and I can take pics if needed. Its a trick pony to pull out, and even harder to "push" in place. After the fight to fit the new sensor in, I reconnected my battery and started the thing up. Idle was slowly getting better. Score.

Its been about 48 hours and so far, no sign of any other issues. Seems to have solved the problem. :D

I haven't searched this entire forum yet, but correct me if I'm wrong, all I see is where people talk about the cam sensor actuator and cam sensor postioner towards the front of the engine. Not the crank position sensor. Oh well, maybe this will help someone with the same issue.:coffee
 

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2002 olds bravada
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Can you post the pics? I'm looking to change mine real soon and see if that helps my idling problem.

Thanks!!!:)
 

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2005 chevy trailblazer_ls
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Discussion Starter #3
Yeah I'll get pics up a.s.a.p. Probably after work around 5pm.

By the way, its been 72 hours now and no hiccups. Score.:D
 

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2005 chevy trailblazer_ls
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Discussion Starter #4



This is a pic of the intake side looking down, towards the driveshaft. You can see I highlighted the sensor in red. It sits atop another sensor. These pics were taken after I installed the new one.






In this second pic, you can see the sensor has a 10mm bolt holding it to the engine. Just unplug the safety latch (the little grey plastic part of the plug that secures it), then unplug the main black plug for the sensor and wiggle the old one out. CAUTION!!! BE CAREFUL pulling the sensor out!!! It takes time, effort and patience. You break this sensor off into your truck....lights out! Get ready to tear down the entire block just to save a $20 sensor from grinding away. Ha!

Installing the new one is extremely tight and tricky. I tried from the bottom, but found out if I climbed onto the engine and reached down, I had more control. Its hard to see from underneath. Everything is in the way. Well, unless you luck out and it pushes right in. I put the sensor in the hole, started the 10mm bolt and lightly tapped it with a rubber mallet to ease it in. Seemed to work out good. After all was said and done, I started the truck, then let it run and smooth out a little. A fellow mechanic said that re-learning is only an issue if I start having problems again. So far, So good!

Any questions? Ask!
:coffee Cheers
 

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2002 olds bravada
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Thanks for the pics! I'm gonna try this if my idling issue isn't resolved! :thumbsup:
 

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2002 olds bravada
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Hey havok. just wanted to see how your truck is running with the new sensor. Did you need a relearn at all?
 

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2004 chevy trailblazer_ls
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Same issue...

My girlfriend is having the same issue with her 04 Trailblazer. When you are sitting still it has a rough idle and when you slow down at times the vehicle will stall. Has anyone else replaced this and had good luck with it fixing the prblem? I would love to go out right now and buy this part but I'm laid off so just trying to get a little more input before I do. thanks
 

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Ok I changed this part the Crank Postion sensor... So now I still have the same problem.... I can seem to find the CAMShaft Postion Sensor. Where is this part located... I cant believe that a 25000 dollar SUV is getting the best of me and I work on Fighter aircraft.... I am getting flustered can anyone help.....
 

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2002 olds bravada
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also you might wnt to pull out your camshaft actuator solenoid and see if the little screens on it are clogged.. that can also cause you a problem
 

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HAHA True I didnt think I that... Thank you for the post I feel a lot better now. I was really going nuts that Haynes Repair Manual was really no help at all. I guess I should have bought the big book from GM.
 

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help!! crank position sensor

hi everyone! I am having issues with my '04 TB... the check engine light came on last week... took it to auto zone, they said it was the crank position sensor. the guy there also said there's 2 of these in my car, and lucky for me, it's the cheaper one that needs to be replaced. a $24 fix. So, I came on good old trailvoy.com and searched and got to the fantastic detailed post with photos too! so thank you thank you thank you! :) BUT... i have a question. Keep in mind I am a female with very little mechanical skills (ok almost none!)... the other day I left my TB on while I ran into the store, I came out, and it was stalled... I am taking it that from the helpful post that this all has to do with the crank position sensor... correct? another question, would this same sensor cause my vehicle to not start up? I came out of the grocery store yesterday and it just wouldn't start. After sitting there being angry for about 10 minutes i tried again and it was a rough start but it started up. I took it home and parked it. About 3 hours later I tried to start it again and it started right up... and I did this about 3-4 times just to make sure... can anyone help please?!? :) I apologize because I am very long winded... But I appreciate any help that anyone can offer! thank you SOOOO much!!! :)
 

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2004 chevy trailblazer_lt
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Just to add to our esteemed guru, also get your battery load-tested. (Any parts store or battery dealer will do it for free. It literally takes more time to pop the hood and find the prop rod than to run the load test.)

The reason I say this is because when your vehicle stalled - and likely from a dirty throttle body - the ignition was then ON, and this drains the battery. When you went to crank it, the voltage was now below that needed to keep the readings from the various sensors such as the crank position sensor. This causes the vehicle to be very hard to start and to run rough for a few minutes. Once the voltage climbs back up, everything goes back to normal.

If your battery is not too old, it may bounce back from being discharged like this. If it is more than 3 or 4 years old, it may be time for a new one anyway. So clean your throttle body, get your battery load-tested, and let us know how you make out.
 

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:thx thank you both so much!! sounds like i have an interesting weekend ahead of me!! :crazy: I will definately let you all know how I make out. Again, THANK YOU!!! :tiphat
 

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Ok I change both the Camshaft and Crankshaft position sensor. I also removed the camshaft actuator solenoid. No issues there. Then I removed the throttle body took a rag and used some ol fashion cleaning. Then I installed the Throttle body and it ran like a dream. after about 10 miles my cruise control stopped working and then it started running rough at idle. Also if I turn on the ac it will just stall straight out. I am out of options other than changing the throttle body. Anyone got a few more tips?? Before the 300 dollar option???
 
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