2014 Ram 1500 3.0 Diesel

Mike Owner/Technician Illinois Posted   Latest  
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2014 Ram 1500 Big Horn 3.0L (M EXF) 8-spd (845RE)
Intermitenly Dies Out

Good day we have a 2014 Ram 1500 diesel 3.0 that intermitenly dies out. No fault codes the vehicle was at the dealer for over 2 weeks . I have read the crankshaft reluctors are common so I have some scope readings to me it appears the crank sensor is dropping out when it dies. I apologize I know just enough to get in trouble with the scope and am far from a expert when using it. To me it looks fairly obvious its dropping out . What are your guys thoughts.

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Michael Diagnostician
Illinois
Michael Default
 

What kind of crank sensor is this? Also how did you connect your scope and were you using peak detect?

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Mike Owner/Technician
Illinois
Mike Default
 

Its a hall effect sensor I set it on the 5 volt scale I don't belive it was set to peak detect. Thank you for your help.

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Michael Diagnostician
Illinois
Michael Default
 

How were you hooked up with the scope? I see that the signal does not go fully to ground or fully to 5 volts. This is a 5 volt sensor correct?

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Mike Owner/Technician
Illinois
Mike Default
 

Yes its a 5 volt sensor

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Michael Diagnostician
Illinois
Michael Default
 

Hook up another channel to ground and another one to the feed of the sensor. Redo the capture and put on peak detect. Since your on a longer screen your scope could be aliasing. Also how many teeth are on the reluctor?

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Mike Owner/Technician
Illinois
Mike Default
 

Ok will do no teeth on the reluctor it is a magnetic stip attached/glued to a piece of metal looks like the magnetic strips are common for cracking.

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Brian Owner/Technician
Ohio
Brian Default
 

There is too much time on the screen for your signal. I recommend setting your scope to around 50-100ms time base or shorter and 10v scale so you have detail you need. The snapon scope is funny with a long time base. Redo your same test. You will have to pause it right at the time it stalls and zoom out on your capture. I would also recommend a ignition trigger to see if you loose it at the same…

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Ray Diagnostician
Ontario
Ray Default
 

The engine is a diesel so use an injector as the trigger with the ckp.

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Robert Mobile Technician
Michigan
Robert Default
 

Mike, These are a 60 minus 2 reluctor. The most common complaint is the vehicle will crank won't run. The best place to make your connection to monitor the crank sensor is at the inline connector on the passenger side of the engine. You can monitor the injector pulse. The hall effect on these is a really tight pattern. You will have to do some measuring and a long time base to catch a drop out…

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Mike Owner/Technician
Illinois
Mike Default
 

When it dies out typically it restarts with out a long crank time. It’s just like some one turned the key off.

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Brian Owner/Technician
Ohio
Brian Default
   

Yes, thanks Ray. Sorry about that. Brain fart!

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Ray Diagnostician
Ontario
Ray Default
 

This is a 58 tooth ckp capture and the RPM Math Channel can find any intermittent or missing ckp toggles. I don't know if your scope has the RPM Math Channel

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Angel Technician
Massachusetts
Angel Default
 

Hello Ray, great capture. I know of math channels. But Im guilty of not using them. in your capture the math channel is picking out the drops in the signal? But every drop in that capture is a sync notch correct? Just trying to make sense of it. Thank you

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Ray Diagnostician
Ontario
Ray Default
 

This capture is from an 07 Jeep 3.8 The red CH B is the ckp and the ckp's black RPM Math channel instantly finds the ckp's missing toggle and then the PCM stops triggering the coils. The blue CH A is the cmp The green CH C is the 2/5 coil primary volts The tan CH D is all coil amps

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Angel Technician
Massachusetts
Angel Default
 

Great example Ray! Thank you for sharing! I can see how it can be useful!

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Rick Technician
Illinois
Rick Default
   

I was just messing with one of these the other day. I happen to have a Verus capture. When the reluctor goes bad, it's game over. It does not restart, the magnetic strip peels off. This is one with a brand new reluctor.

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Ray Diagnostician
Ontario
Ray Default
 

It looks like the scope measurement is negative .3v to negative 5v?

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Rick Technician
Illinois
Rick Default
 

Didn't realize it at the time but it's inverted. I was more concerned with the pattern

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