P0335 P0340 06 Tacoma 2TRFE (Crankshaft/Camshaft Position Sensor Circuit)

These codes showed their ugly heads a few months ago. I have a 2006 Tacoma 2TR-FE.

This problem has been plaguing me for the past few months, and I'm not sure what to do next. Both codes popped up together after I tried to start it one day, and it would just crank and wouldn't start. After a few times of cranking and holding it for like 30 seconds, it stuttered and finally fired up and ran just fine, no weird running issues, and felt normal. After that, it started every time with no issues. The truck was starting flawlessly for about a month, and then the codes came back, and the truck just wouldn't start. So my next course of action was to replace both the cam and crank sensors with genuine DENSO replacements. I got both swapped out, and the truck fired right up, once again starting flawlessly. I was sure that fixed it because no problems or codes came back, then after a few weeks, they came right back. This past month, it has been happening more and more frequently. The only common denominator between these 2 sensors is a common "ground" wire that goes to each sensor, so I tested the wiring and it seemed to check out fine. The biggest thing about this issue that stumps me is that once I get it started after a lot of cranking, it will run beautifully. No lack of power. No missfiring. No Running issues AT ALL. But once I shut the engine down and try to start it again, it will have a long crank again, or other times it will start right back up. Its behavior doesn't change whether it's been sitting and cold or been running for 6 hours and is up to temp. Once I shut it down, it's like a coin toss whether it will start right away or want to take its time, but I have managed to get it to start every time. My hunch is leading me to believe that the ECU is the issue, but I don't want to just replace parts without knowing the cause.

Any insight and help on this problem would be greatly appreciated. I haven't been able to find anything online about a problem similar to this, so hopefully this can help someone in the future with this same problem. (hopefully after this is solved)

 

Since you replace both the sensors, you are really going to need a scope to help figure this out.
I suppose you could ohm check the wires to/from the ECM.

Scope at the ECM terminals is the best method to diag this.

 

@TnShooter Thank you very much for your very quick responce. I just got around to doing some diag and these are my findings so far.

I probed right at the ECM connector. the first 2.08k reading is the resistance check to the crankshaft position sensor and it falls in the middle of the acceptable resistance readings.
I also checked the camshaft position sensor aswell and got 1.09k. In addition I probed each wire to ground and got OL which is good. aswell as probed across both of the + wires since they share a common - between the 2 sensors and got the combined resistances which is to be expected.

so far I can't find a problem with the sensors or the wiring.