2011 Buick Regal CXL — P0336

David Technician Saginaw, Michigan Posted   Latest   Edited  
Question
Driveability
2011 Buick Regal CXL 2.4L (C LAF) 6-spd (MR6)
P0336 - Crankshaft Position Sensor "A" Circuit Range/Performance
Extended Crank/Start
Rough Idle

Vehicle has long crank, runs rough. Scope shows crank signal at sensor and ECM. Not showing RPM in ECM data. Signal wire tests good from sensor to ECM. Crankshaft resync counter showing 37. Hate to just throw sensor at it when I'm not seeing cause??

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Albin Diagnostician
Leavenworth, Washington
Albin Default
 

have you checked the code set criteria? What does the cam and crank sensors signals look like, and are they properly aligned?

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David Technician
Saginaw, Michigan
David Default
 

I will scope cam to crank tomorrow.

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Brandon Diagnostician
Reading , Pennsylvania
Brandon Default
 

Although the signal is present , does it reach full amplotude? What does the DTC dictate? Is it a circuit code?

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David Technician
Saginaw, Michigan
David Default
 

Code criteria states, not present or not correct count. I am using scope on scanner and tried to count terth, it looks funky. I don't see 58 and 2 dead. More like 26 and 2 dead. I'll be doing more testing tomorrow

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Albin Diagnostician
Leavenworth, Washington
Albin Default
 

GM is very good at giving you the code set criteria. Once you know that information, most of the searching for the problem is now gone, and you can go right to the problem and test it. Get the needed waveforms and you will have the problem nailed to the floor.

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Ray Diagnostician
North York, Ontario
Ray Default
 

If your scope is a Pico, can you please post the PSD file! This capture is from a good 2012 Equinox 2.4

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David Technician
Saginaw, Michigan
David Default
 

I'm using 4 channel scope on scanner,

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Caleb Technician
Mishawaka, Indiana
Caleb Default
 

You need to scope the cam and crank sensors for signal quality/amplitude etc. Also very important to compare to a known good to check the timing. You do this and you will find your issue.

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David Technician
Saginaw, Michigan
David Update
   

Channel 1 - Crank Channel 2- Intake CMP Channel 3- Exh CMP I have nothing to compare it to , thank you guys for all the help! I think that Crank looks weird. This is a 2011 Buick Regal with a 2.0 Turbo , 6 Spd Manual Trans

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Caleb Technician
Mishawaka, Indiana
Caleb Default
 

Awesome, there is the problem. This crank reluctor is 60 tooth -2 teeth for 360° and TDC. I count about 27 teeth from the left side till we see what looks like severly damaged or missing teeth. Make sure the damaged portion occurs every 360°. If so the reluctor has a problem.

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David Technician
Saginaw, Michigan
David Default
 

Ever done one on these? better to just find a low mileage Engine?

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Caleb Technician
Mishawaka, Indiana
Caleb Default
 

Do you have a Service info source? Honestly man , I have no idea. I avoid engine work as much as possible. But being as the reluctor is part of the crankshaft and the crank has to be removed to replace it, Id assume probably cheaper to just put another engine. However the 2.0 is not as popular as the 2.4. Don't know how many are out there.

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David Technician
Saginaw, Michigan
David Default
   

This is my personal vehicle. I'm leaning towards dropping and fixing as there are none around here less than 100k for 1200$. I don't have SI, but do have access to identifix.

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