Help needed solving codes P0374 P0171

I am having issues with my 2005 Toyota Tacoma V6 Prerunner 2wd. I am trying to get it inspected but it will not pass due to the check engine light being on. The codes I get are P0374 and P0171. I have searched and found little information on the code P0374.

I have replaced the Crankshaft position sensor, which was a PITA btw! lol
I did the sea foam treatment in the vacuum line.
Changed oil, air filter, spark plugs, etc. all the basic maintenance and the truck is running great minus the codes.
The truck has 270,000 miles on it and has had zero problems since I bought it brand new.

My next thought was to replace the camshaft position sensors but wanted to see if anyone had some better information for me. I’m hoping it is not a wiring or computer issue.

Thanks in advance and I am posting pics of the data I have from my code scanner.

 

Check obd-codes.com for what you may need to check and possible reasons. Look for rodent chews on the wires.

 

https://repairpal.com/obd-ii-code-p0374-timing-reference-high-resolution-signal-a-no-pulses

This site gives potential causes and what you will see with this code. I linked you directly to your code. hope this helps

 

Thank you... According to that I can add Fuel Injection Control Module to the list of possible causes and maybe remove the camshaft position sensors. I saw on other websites that the camshaft sensors could cause this as well... Anyone know this for sure?

Also can anyone give me an educated guess as to what’s wrong given the code reader data in the pics? I know I might be asking for a crystal ball type diagnosis but I’m desperate here lol!

 

Still open to any suggestions if anybody has any ideas

 

P0171:

http://www.customtacos.com/tech.old...06toyrm/06toypdf/06rmsrc/rm2006ta/0060027.pdf

P0374:

This is a valve timing issue and I would look at the Timing Oil Control Valves and VVT Sensors for Cam Position for the VVT system. Also involved would be damage to the wiring for the solenoids and the Sensors.

http://www.customtacos.com/tech.old...6toyrm/06toypdf/06rmsrc/rm2006ta/00500310.pdf

Sensor Locations:

 

VVT solenoids are highly suspect too.

Whoops - Jimmy covered that above.

 

Thank you JimmyH!

I just saw your reply, my notifications are off I guess lol. I had ordered two VVT sensors and replaced them, still getting the same codes. So I need to be looking at the solenoids and the wiring to all of the above correct? Should I be looking at the wiring at the crankshaft position sensor? I am hoping you say no because that was a big pain to get to! Lol

FYI the truck is running fantastic, but still getting the codes. My registration was up 7/19 so I am trying to solve this as fast as possible. Thanks for everyone’s help, I really do appreciate it!

 

Still needing HELP!

I saw my last post and thought it might come across as problem solved to some people seeing it at a glance lol.... man I must seem desperate lol!

 

I would double check the wiring harness to all of the above and also check the filters to the VVT Solenoids.

Here are the locations to the filters. If they are dirty it will effect the solenoid operation and valve timing.



It looks like a bolt head on each side of the block:

 

So I tested the voltage at the connector for the crankshaft position sensor and got 0.01 volts. Then I traced the wires all the way back to the computer, checked continuity and got 0.5 ohms on both. Anything above 2 ohms is supposed to be a bad wire so the wires are fine.

Also I checked the voltage of the VVT Sensors and got 5 volts, then checked the VVT Solenoids and got 1.15 volts on one and 1.04 volts on the other.... I'm not sure if those numbers are correct and I can't find anything to confirm it either. I did clean the VVT actuator filters, cleaned all connectors, and used dielectric grease on everything. I changed all the spark plugs and coils.
I also checked all the sensors and they are spot on..... Am I looking at a bad ECU?

Thanks!

 

Got everything back together and am still getting the same codes.... I’m stuck and my inspection has been out for a month. Does anyone have any ideas? I’m desperate!

 

Well, I was stumped and ended up reading the codes with another reader and it gave me p0171 & p0174.... which was different than my reader saying p0171 & p0374. So I took it to AUTOZONE and theirs read p0171 & p0174. I had no idea code readers could read wrong like that ‍♂️
I did a lot of work for nothing omg

 

Right? I mean damn Walmart code reader !

 

Lean bank #1 and Bank #2 I always look at air flow meters.

Something that is connected to both banks that controls fuel trim.

This can be Fuel pressure, MAF, or Intake leak.

It eliminates, one or two injectors, a misfire, o2 sensors etc.

 

So I ordered a new MAF sensor from Amazon and installed it today.... stupid codes popped again ‍♂️! So I still have the problem.

 

Here is a 2nd gen owner with the same issue, cause was a clogged fuel filter screen.
https://www.tacomaworld.com/threads/po171-and-po174.247788/
Based on other threads, there is no replaceable fuel filter for these model trucks.

 

Thanks, I just searched and found a few, the one you linked is closest to my situation...
According to the consensus I am looking at this probability:

90% Faulty Fuel Pump/Filter
7% Faulty AF Sensor
3% Broken intake flange

Wish me luck lol

Also can anyone tell anything from the pictures I posted or does that meter not give enough information? I have the other meter but I have no idea what I am looking at... what will it say for the fuel trim? Thanks