***2006 Toyota Tacoma 4.0 starting problem***

Hey guys I’ve been having problems with my Toyota Tacoma starting up it throws a code for a bad camshaft position sensor code P0343 which would be the passenger side cam position sensor. I have replaced both sensors I purchased them straight from Toyota and it still throws the same code, any suggestions on what to check next?

 

Has your timing chain ever been changed? How many miles on your truck? If it's high milage, it could be stretched or your tensioner could be worn. I've also read at least one account of sludge that affected the flag for the timing sensors.

 

It has 150,000 miles, is far as I know there has been no maintenance done to the timing chain. Once it fires up the timing chain makes no noise and runs like a top afterwards. Sometimes I’ll hop in and it’ll fire right up at the turn of the key. Any tips on cleaning out that sludge without disassembly? Thanks!

 

P0343 / VVT position sensor (Bank 1) range check - (high voltage)
The code is set when Output voltage of VVT sensor 4.7 V or more for 5 seconds.

You need to find out why the VVT is putting out more than 4.7V.
Or why the ECM is saying it’s over 4.7V.

 

Interesting. When I google P0343, it refers to the camshaft position sensor, not the VVT solenoid. If the VVT voltage were set above max for >5 seconds, that indicates your timing is WAY out or the ECU thinks it's way out. In my google search, every page suggested making sure your battery is healthy. Apparently, you can get this code from having marginal voltage. Also check wires for indication that rodents have chewed on them.

I've had this code personally on a motor with 220K miles. The tensioner failed, causing slack in the chain. Timing can be checked with the valve covers off. Tensioner can be inspected through a view port at the front of the engine.

 

TnShooter sent me the link to the shop manual and what he said makes more sense to me now. Thank you TnShooter! VVT timing sensor and camshaft position sensor are synonymous, which threw me off a bit. The failure code P0343 indicates that the sensor failed the electrical diagnostic test. It looks like it's performed when you roll the ignition from off to on. Though I'm not sure why it results in a high voltage failure, a quick Tacomaworld search uncovered at least 3 cases where animals chewed the wiring harness right at the sensor connector.

One example here: https://www.tacomaworld.com/threads/magnetic-sensor-identification.510857/#post-16052213
Two examples here: https://www.tacomaworld.com/threads/p0343-code-rough-idle-inconsistent-start.598946/

I'd do a careful visual of the harness and connector first. If that doesn't reveal the cause, there are suggestions on how to check the pins to the connector. Basically, Pin 3 is a 5V supply. Pin 1 and 2 are signal and ground (not sure which is which). You can ohm the wires and test for voltage.

 

Sounds like you read it just as I do.

If the wiring checks out good, it’s either the cam plate (gear) or ECM.
Those are the last 2 things I’d suspect to go wrong.

Usually when the timing chain stretches it causes a Crank/Cam Correlation code.

Best of luck to you buddy.

 

What voltage should the truck be supplying to power the VVT solenoid?

Testing with the key in the ignition turned to the "on" position and using a multimeter to measure at the connector which attaches to the VVT solenoid (this connector only has 2 points of connection so measuring Voltage here is pretty straightforward). I'm just curious as to the voltage (or acceptable range of Volts) to expect to know if I have a properly working electrical signal going to my VVT solenoid.

Hope this question is relevant enough to this thread and that someone might have a valid answer to my question.

Thanks in advance.

 

I wouldn't expect to see anything there KOEO, the PCM only moves the timing at higher engine speeds and loads, at idle and engine off the VVT solenoid isn't doing anything.
The PCM controls both wires using a PWM (duty cycle) signal, you would need an oscilloscope to see what it is doing, measuring voltage there wouldn't tell you much.

You would most likely get a P0010 code if there was a problem in the VVT Solenoid circuit or a P0011/12 if the solenoid was sticking/not functioning.

What kind of issue are you having?

 

Nope. I was looking for a simpler answer, and especially not another question. I simply was wondering what a healthy truck has for voltage reading at the VVT solenoid connector with the key in the "on" position but the engine off.

If I am " having any issues", it's too many to list. The list would begin with: #1. my back/spine and it's constant aching. I'd follow that with #2. the constant and reoccurring issue of having to find some sort of caloric intake for my bodily systems to continue to function. #3. the inability to find the information I'm seeking of the voltage expected when measured at the truck side of the harness connecting to the VVT solenoid.

I'm not concerned with how the route of the voltage gets there or by which switching method of the computer it takes, just simply curious as to what the voltage should be.

 

When I said issues I meant problems with the truck, I wasn't trying to be rude.
This is the best I can do with what your asking.
Here's what the waveform should look like idling, I would have to assume a voltmeter would show around 3v idling since all a voltmeter does is average voltage.
I apologize if this isn't the answer you were looking for but that's the best I can do and the scope capture below is the only voltage info that's provided in the service manual for the solenoid.

 

That's closer to what I'm looking for. Thank you.

I'm simply trying to identify that with the truck off, but the key in the ignition turned to the "on" position that there is the proper amount of electricity being supplied to indicate the wiring is in fact okay and not a cause for fault of the VVT. I know that the voltage represents an average, but that's perfectly fine for for this situation. If the wires are damaged in any way that the electrical signal still travels through to the point where I'm testing but at any lesser degree due to the damage, then it would "average" out to be less Volts that would be measured. I am hoping to find a value in Volta that I can use as a determining point to decidedly say that the wiring harness, including everything before that point such as all the supporting wires and components leading up to the point where I am measuring at on the wiring harness plug to the VVT solenoid, is in fact (or not) in full electrical working condition. Seems simple enough. Or so I thought.