P0340 Camshaft Posiion Sensor "A" Circuit Malfunction (Bank 2 or Single Sensor)

Hi Guys,

 

I recently installed a new clutch and wrx flywheel on my 05 OBXT. The install went relatively smoothly, just time consuming. When I went to fire the car up after the install, I came across multiple issues. On initial start up, it was difficult to get the car to start. It took multiple cranks, until it fired and would hold an idle. I noticed the idle was a bit lower than usual, and it was incredibly rough (lots of excess vibration). A quick check on my accessport revealed the ecu was throwing code P0340. I then went for a small drive around to check the clutch was operational. I noticed very quickly when I went to accelerate a little harder than regular driving. The car would buck and hesitate quite violently. After this I parked the car, and have been trying to figure out what is going on. Part of me feels like the timing belt may have skipped a tooth, or that the sensor itself has failed. I find it quite odd that then sensor would fail so randomly, so I'm leaning towards the a skipped timing belt.

 

Has anyone experienced this problem before? Are there any other things that could be the culprit of this? How would I go about verifying that the timing is correct? Any help would be greatly appreciated. Thanks in advanced!

I doubt its the timing belt.

 

Its more likely something you forgot to do. Go back over everything, make sure all the ground wires are connected.

 

Did you remove the battery cable ? If so you have reset the ECU, when doing that you should turn the key to ON for 10 seconds before you start the engine.

 

Have you pulled the passenger side cam position sensor and cleaned it or at least make sure the connector is clean and tight.

Thanks for the input Max Capacity, I'll have another look on the weekend and give you guys an update with what I find.

 

Another tidbit of input that might help me out, there is a ground wire that goes from the pitch stop mount on the firewall to the transmission. I didn't remove it and the ground ended up being broken off as I removed the transmission. I repaired the wire and instead of bolting it to the 2nd or 3rd transmission case bolt, I just used the first case bolt. Could this be the cause of my issues? I don't think it would be because a ground is a ground, but who knows, these Subaru's are a little bit finicky

In that case, a ground is a ground.

 

The ones on the bottom of the heads have the most issues.

 

Oh BTW, PM CT08Spec.B he can save you money on insurance for the car and the home. Tell him I sent you.

in that case, a ground is a ground.

 

The ones on the bottom of the heads have the most issues.

 

oh btw, pm ct08spec.b he can save you money on insurance for the car and the home. Tell him i sent you.

 

lol wtf?

I'm posting this here because I recently got the P0340 code and struggled to find the definitive answer as to what sensor to replace (and the effort of which).

 

As you know the P0340 code is the Camshaft Position Sensor 'A'. I got the CEL when I merging from one highway to another around 75-80MPH. I got a few stutters, then loss of power. I pulled over to the side of the highway, reset, and upon launch got a backfire and loss of power. I limped home noticing occasional loss off power at highway speeds.

 

I did my due diligence and tried to find someone with a clear answer as to where the sensor was located, etc. Here is what I discovered:

 

On the '05 LGT there are two camshaft position sensors (driver and passenger). The passenger side one is 'A' circuit (P0340 code), the driver side one is 'B' circuit (P0345 code). I did the 'A' circuit, but this might help with the 'B' circuit as well.

 

The part was about $22 from NAPA.

 

1) Remove your turn heat shield (3-4 screws)

2) Remove the heat shield bracket (one nut on the downpipes, one bolt into the block).

3) Unplug the sensor above the bracket (I'm not sure what this sensor is)

4) Unplug the camshaft position sensor

 

Ok, here's the problem. Even the shallowest socket I had wouldn't clear the sensor above the camshaft position sensor while trying to get the bolt for the sensor out. Luckily the bolt holding the sensor in place was hand tight once I broke it loose with about 1/64th of a turn.

 

Removing the sensor is a frustrating task. There's just not quite enough room for fingers in there... it can be done without removing anything else, but be prepared for scratched hands, etc.

 

Getting the bolt back in place can be a trying experience (but we're used to that right?). The shape of the sensor doesn't allow you to get any rotation on the head of the bolt with an open ended wrench, and there's not enough space for a box end. A socket fits, but you can't get the ratchet on.

 

After struggling for a while, I looked through my toolbox and found this : http://www.harborfreight.com/3-piece-square-drive-socket-caps-67011.html if Harbor Freight no longer carries them, basically they're adaptors that go on top of a socket and allows you to use a wrench to turn them. Without this I don't think I could have gotten the bold for the sensor back in place.

 

Once you get the bolt back in place (by far the hardest part), put everything back in reverse order.

 

I did this in the cold and rain and struggled for a good 30 minutes getting that damned bolt back in before I found the socket adapter. Overall this should only take you 60 minutes to swap.

 

The code will clear itself after a while, or reset with your OBDII tool or Cobb Tuner.

Just did this today. No idea how you got the sensor for $22, closest I could find was $82.00. Anyway, I was able to get the sensor out with a 10mm open end wrench and then use my fingers to get it the rest of the way out. Anyone else trying this...word of advice. When placing the new sensor in, go ahead and put the screw that holds the sensor in place into the sensor itself before placing the sensor back on the engine block. There simply isn't enough room to truly get your hands in there.

I'm throughly confused here. As my post above indicates. I replaced this sensor a little over a year ago. Today I got the code again.

 

It's odd because this time the car is reacting completely different from the last time.

 

This time it struggles to start. Once started it operates normally though. Last time it wouldn't accelerate and was operating in a limp mode.

If it's been good for a year you probably have a bad sensor. Maybe go with a better brand this time?

Did you remove the battery cable ? If so you have reset the ECU, when doing that you should turn the key to ON for 10 seconds before you start the engine.

 

could this cause my issues im describing in my post? the car sat from nov 2014 til feb 2016 with a dead battery, all i did was put in a new battery, hook up cables, and start it up.

I had the same code P0340 found a bad ground on the cam sensor plug. But if you want to check the voltage I had 11.8v on the red wire and 4.8v on the green wire she runs good now that I fixed the ground. (Ignition on not running)