2010 Prius P0A0F-524 and P0335

Travis Owner/Technician Oregon Posted   Latest   Edited  
Resolved
High Voltage - Hybrid & Electric Vehicles
Electrification
2010 Toyota Prius 1.8L (2ZR-FXE) (P410) — JTDKN3DUXA0143211
P0A0F — Engine Failed to Start
P0335 — Crankshaft Position Sensor "A" Circuit

Seems pretty cut and dry, NE signal error. Put in new OEM crank sensor today same thing. Does anyone have any suggestions or notice anything I am missing in the Freeze Frame data?

Thanks!

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Darren Technician
Wisconsin
Darren
 

Let’s see some cam crank scope captures

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Ahmad Engineer
Jordan
Ahmad
 

Have you made a cam crank wave scope?

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Arsalan Owner/Technician
District of Columbia
Arsalan
   

Hey Travis, not to be rude but how did you figure out if CKP sensor was bad? was it because of the DTC P0335? whats the history on the vehicle? these battery seems weak to me and I always had issue with toyota with starting on weak battery?

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Eric Owner/Technician
Michigan
Eric
 

Freeze frame data on Toyota isn't a big help when diagnosing issues. What else besides changing CKP have you done. This is simple to grab the CKP signal with a scope, I have yet to see a Prius with a bad timing chain, so I wouldn't suspect that timing has changed. Have you verified the basics, spark, fuel, etc.? Compare relative compression with a synch probe to #1. Quick and easy. This tells…

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Grant Technician
Illinois
Grant
 

Based on the freeze frames, my assumption is that this is not a hard failure. If you clear the DTC's, you have to drive it a few minutes before the DTC's will reset. I would be scoping the CKP while driving or at least while running ICE at high rpm.

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Matt Technician
Massachusetts
Matt
 

Looking at the freeze frame: You have an engine speed signal so the PCM is seeing something, but maybe it doesn't like what it sees. I'd scope it. Here's a known good screen shot. I'll try to find the raw file. The MAF is measuring air but the MAP is showing atmospheric pressure at 13-14PSI. Could there be a large vacuum leak (purge, PCV or both lines off)? This would explain the P0A0F. At -3…

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Matthew Diagnostician
Kentucky
Matthew
 

I beleive this engine atkinson cycles if im not mistaken that might explain map reading at idle.

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Matt Technician
Massachusetts
Matt
 

Correct, but it should still create vacuum at lower RPM. Here's a data capture from a Gen 3 Prius at idle.

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Matthew Diagnostician
Kentucky
Matthew
 

Most engines that Atkinson cycle will have much lower vacuum at idle as well for pumping loss reduction. They will phase the intake cam retarded and open throttle more. newer engines fake Atkinson cycle and also for start up Emissions reduction and pumping losses where the intake timing is also retarded. that scan data also shows low vacuum at idle as well with map pressure at 1300 rpm near 13…

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Matt Technician
Massachusetts
Matt
 

I totally agree but I still feel on the freeze frame at -3 the vacuum should be lower. My data capture was not a cold start but you can see where the ICE cranked and vacuum was created.

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Mohammad Owner/Technician
Illinois
Mohammad
 

I am wondering with all the provided info (!), did this vehicle ever get fixed…? Any update on its status…?

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Travis Owner/Technician
Oregon
Travis
   

On a hunch put a cam sensor in it. Fixed…. will post waveform from bad one when it gets scoped

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Travis Owner/Technician
Oregon
Travis Resolution
 

On a hunch put a cam sensor in it. Fixed. Will post waveform if we can. Thanks!

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