A simple scan tool case study

Jim Educator California Posted   Latest   Edited  
Case Study
Driveability
2000 Chevrolet Cargo Van 5.7L (R L31) 4-spd
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Geoff Diagnostician
Hawaii
Geoff
   

I'm seeing MAF making no sense with regard to RPM, or at all in spots, and RPM makes no sense either, in spots, like 7500 RPM on THAT rig? No. TPS shows zero always, so the DTC is "logical" but without being there to rev the engine myself and see wtf the engine actually does, IDK who all is lying about what. I have to guess wiring problem, without knowing if any sensor value real. I'll check…

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Darren Owner/Technician
Arkansas
Darren
   

Well, this is interesting! First off is the rpm, 7500? no I don't see that plausible. So just taking a guess mind you I would have to lean towards misrouted wiring or excessive coil secondary noise tricking the PCM. Just a guess at this point. Last year I ran into a similar situation on a later model box/van with ETC. One of the tip offs was an insane RPM pid. It was the wiring harness had…

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Jim Educator
California
Jim
 

I forgot to add… I will be posting part two of the case study which came from flatrater​.​com and is now available elsewhere.

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Geoff Diagnostician
Hawaii
Geoff
   

when? where? Inquiring minds wanna know.

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Jim Educator
California
Jim
 

Video first as it will set the stage

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