2012 Prius refused to Start. Error Code P0335 – Crankshaft Position Sensor A Circuit Malfunction

Thanks! I will look up the service manual and try what you suggest. I wrote DENSO a question about my use of a non DENSO crankshaft sensor and below is a copy of text from their reply

DENSO does not approve using ‘’ none DENSO parts”, we have no control, or knowledge about parts that are not made by DENSO; OEM or Aftermarket.



We would suggest that you install the correct parts as a first step to resolve your problem.

 

Installed the Denso crankshaft sensor, but still have the non start problem. So now I have to use the repair manual link and my old analog meter to check for a short in the wiring from the sensor to the ECM connector. If anyone knows a link to step by step instructions for removing and replacing the crankshaft sensor wiring then please leave a reply!

 

I need to see how from the manual to do a visual check of the reluctor wheel on the crankshaft that my sensor is not reading. I was told by a mechanic that he was able to check the reluctor and it is good. I want to know how to check that myself! I still have to test the sensor wiring(Texas heat has been repressive since June)

 

I was able to look the removal procedure up in my copy of the 2010 manual. Unfortunately the rotor is under the chain under the chain cover on the passenger side of the engine. I cannot even imagine how there would be any simple inspection proceedure due to the need to take off possibly the water pump(and I know the gen3 pump is electric, so I don't know how that position changed on the gen3 engine) and at least the pulley and oil seal in order to take off the cover! If anyone has a simple way to verify that the rotor is not damaged then please let me know! I will check the wiring and maybe find a shop that can use a diagnostic program to check my ECM if the wiring is not at fault. I already know I have a leaky oil pressure sensor. And have wondered if this has been a source of corrosion of the crankshaft sensor wire! I can get a new connector and wires from Rockauto if needed. Replacing that will be uncomfortable in this Texas heat!

 

I don’t understand how an oscilloscope reports information. Do you recommend a good site to learn more?

 

An oscilloscope (scope) is an electronic graphing tool that lets you see and record the actual signal. High dollar scanners sometimes have similar looking graphical displays but they are just graphing samples of obd2 data. A scope (or sometimes a quality graphing multimeter) can display actual analog (varying) signals directly from a sensor. When monitoring two or more signals it is possible to measure the timing between inputs or events on an input.

Example


It's an advanced technique that requires fairly expensive tools like a Picoscope brand ($3k) that can capture analog waveforms quickly. It also requires very good experience and often known good displays (sometimes provided in online Toyota repair manuals).

HOWEVER, most no start problems are simpler than a camshaft that has shifted timing which might be seen on a scope. For the tech who has the tools and experience a scope can be faster than simply measuring average voltages or blindly changing sensors.

The diagnostic tech in the video below uses scopes frequently, is a specialist dealers call, but knows how to check air, fuel and spark quickly.

This car has a blown head gasket which he deduces quickly but that is not the no start problem. In this case it turns out to be a vacuum line.

Finally, once you fix the problem it usually takes clearing the codes and two or three start attempts.