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Have a 2007 chevy trailblazer - cranks but no start. tested both fuel and spark , both were good. Here is a video of it cranking.
also has CEL code p0017.

Thinking maybe the timing chain. appreciate any advice or thoughts.
 

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tested both fuel and spark , both were good.
HOW did you test for "fuel"? Simple fuel-pressure test, or did you verify that the injectors are firing?

HOW did you test for "spark"? Did you verify that you have spark ACROSS THE PLUG GAP, or just that the coils fired? Did you use a spark-tester calibrated for HEI ignition systems, so you know the available spark voltage is sufficient? Are the plugs fouled or worn/damaged?

also has CEL code p0017.
A quick search indicates that P0017 is crank position sensor/cam position sensor misalignment. Worst-case would be a broken timing chain; which might lead to a bunch of bent valves. There could be other things that set that code. Follow the diagnostic chart in the service manual to discover the cause.

WHAT IS THE CRANKING COMPRESSION of all six cylinders?
 

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Discussion Starter #3
HOW did you test for "fuel"? Simple fuel-pressure test, or did you verify that the injectors are firing?

HOW did you test for "spark"? Did you verify that you have spark ACROSS THE PLUG GAP, or just that the coils fired? Did you use a spark-tester calibrated for HEI ignition systems, so you know the available spark voltage is sufficient? Are the plugs fouled or worn/damaged?


A quick search indicates that P0017 is crank position sensor/cam position sensor misalignment. Worst-case would be a broken timing chain; which might lead to a bunch of bent valves. There could be other things that set that code. Follow the diagnostic chart in the service manual to discover the cause.

WHAT IS THE CRANKING COMPRESSION of all six cylinders?
We are thinking it is the crankshaft position sensor. I picked a new sensor up tonight and will try changing it tomorrow morning. I dont have access to a lift so i believe going through the wheel well is the best option? anyways thanks for the reply - really hoping it isnt the timing chain.
 

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Wouldn't a failed crank sensor set a DIFFERENT code?

The code you have isn't saying the crank sensor is faulty. It's saying the crank signal is not aligned with the cam signal.

You need to FOLLOW THE DIAGNOSTIC PROCEDURE in the service manual.
 

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Is that from the Genuine GM service manual? Sounds like "internet bullshit" to me. The code is telling you that TWO sensors don't agree, and the advice is that "THE sensor" could be bad? Why assume that it's the Crank sensor, and not the Cam sensor?

And, again, isn't there a different code for a failed cam sensor, or failed crank sensor?
 

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Is that from the Genuine GM service manual? Sounds like "internet bullshit" to me. The code is telling you that TWO sensors don't agree, and the advice is that "THE sensor" could be bad? Why assume that it's the Crank sensor, and not the Cam sensor?

And, again, isn't there a different code for a failed cam sensor, or failed crank sensor?
Update - changed both the VVT solenoid and crankshaft sensor. Check engine light turned off and starting on first try.
 

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Replacing the crankshaft position sensor requires a CASE relearn afterwards.
 

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From what I have read it can be done by anyone with a tech 2 or other high end scanner so not necessarily a dealership. You should be able to find a mechanic or shop that can do it. I believe one issue is that without it the PCM can't determine what cylinder is misfiring should a misfire occur? There may be other issues but I am sure there are a boatload of vehicles driving around without the CASE releatn done.
 

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Have a 2007 chevy trailblazer - cranks but no start. tested both fuel and spark , both were good. Here is a video of it cranking.
also has CEL code p0017.

Thinking maybe the timing chain. appreciate any advice or thoughts.
p0017 is an issue between crank and cam sensors. the correlation is off. it could be the chain has stretched too far. you really need to start with a good scanner to see if they are in synch
 

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Discussion Starter #13
p0017 is an issue between crank and cam sensors. the correlation is off. it could be the chain has stretched too far. you really need to start with a good scanner to see if they are in synch
problem is fixed .. changed solenoid and crank sensor, engine light off automatically and starting/running great.
 
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