Check Engine light - Camshaft Position Sensor “A” Circuit P0340 & P0344 HELP?!

[TrackGT]

I was at a HPDE at Grattan this past weekend. Ran two great sessions and then my third session half way through I got a check engine light. Immediately headed for the pits and my 2015 GT PP was making an awful ticking noise. Almost sounded like piston slap. I also had an extremely rough idle.

The two codes were
P0340 - Camshaft Position Sensor “A” Circuit
And
P0344 - Camshaft Position Sensor “A” Virciut Intermittent

I unplugged the battery and reflashed the tune and the problem completely went away. Sounds like brand new again.

I took it out for another few laps and the same thing happened. Again.

I reflashed the tune again and it went away: drove two hours home with no issues.

Once I was close to home I started driving harder and the codes came back.




Any ideas on where to start? Has anyone else had this issue?

All comments are appreciated.

 

[mwjscn]

Here's the service manual info from 2011. I assume it would be very close to a Gen 2 engine, if not identical - at least as far as the cam sensor and cam sensor connector pinout. I'd have less confidence that the PCM pinout is the same, but I included it just in case. These tests are how a dealership would perform the diagnosis. It requires a multimeter for most steps, but that's a common requirement when trying to diagnose automotive electronics. I don't expect you to follow all the steps, but it can at least guide you on determining the ohm value of a good sensor, checking for dead shorts, and a bunch of other neat tests.

 

[TrackGT]

Here's the service manual info from 2011. I assume it would be very close to a Gen 2 engine, if not identical - at least as far as the cam sensor and cam sensor connector pinout. I'd have less confidence that the PCM pinout is the same, but I included it just in case. These tests are how a dealership would perform the diagnosis. It requires a multimeter for most steps, but that's a common requirement when trying to diagnose automotive electronics. I don't expect you to follow all the steps, but it can at least guide you on determining the ohm value of a good sensor, checking for dead shorts, and a bunch of other neat tests.

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Thank you so much for sharing. I plan on ripping into it today. Update coming soon.

 

[TrackGT]

Thank you so much for sharing. I plan on ripping into it today. Update coming soon.

After checking all connection points and replacing all four sensors, the problem is still there. I did notice it only kicks after 6000 rpms. Any more ideas would be greatly appreciated.

 

[mwjscn]

Perhaps it's an issue that only shows up during vibration, since you replaced the sensors. Clear the code, run the car, and do the harness jiggle test while following it back. It would be helpful to have someone in the drivers seat to see when it sets the code again so you can isolate it to a loom section. stevbd recently posted a place were his wiring harness had worn through on the front timing cover, so something similar may be happening in your case (may not necessarily in the same spot, but perhaps somewhere else on the harness).

https://trackmustangsonline.com/threads/random-misfire-2011-2014-coyote-check-this-section-of-engine-wiring-harness.20918/

 

[stevbd]

I don’t know how the loom is set up on an S550 but I would suggest looking carefully at areas where part of the loom is secured to the chassis and an adjacent part is secured to the engine. The area described in my post is like that. My working theory is the normal slight rocking of the engine under hard acceleration or hard left hand cornering caused not only the chafing but also the intermittent nature of the misfiring, as the engine movement would cause the frayed wires to either make contact or pull away from the metal timing cover. Areas where the loom is attached only to the engine, and moves with the engine, are not as problematic imo.

On my 2011 there is another area of potential similar chafing where a wiring loom is constricted between the bottom of the engine and a metal tab on the steering rack. But Ford put some rubber tape on the steering rack in that area to protect against chafing. And none of those wires go to the cam sensors so I doubt that’s your issue.

My car would misfire under hard acceleration and hard left hand turns on track but run fine if driven gently. It would also not misfire if I revved it gently to redline.

Good luck.

 

[TrackGT]

Here’s a note from Lund… I was hoping to not have to go that deep into the engine… I’ll investigate more on Monday.

 

[Mjschneidy]

I went through this, ended up using Forscan to watch the cam timing and when the code would set. Noticed that the one cam was not well controlled and after a while the PCM would give up and "park" the cams at 0 or home position and set the code. Turned out to be a bad cam phaser. All the diagnostics said intermittent electrical which it was not. Would be smart to swap the cam position sensors around to eliminate those, quick and easy. Good luck....

 

[TrackGT]

I went through this, ended up using Forscan to watch the cam timing and when the code would set. Noticed that the one cam was not well controlled and after a while the PCM would give up and "park" the cams at 0 or home position and set the code. Turned out to be a bad cam phaser. All the diagnostics said intermittent electrical which it was not. Would be smart to swap the cam position sensors around to eliminate those, quick and easy. Good luck....

Thanks for the comment. I already replaced all four camshaft position sensors and it did not resolve the issue. Cam phaser is an interesting idea.

Lund emailed me and said the following:

“Codes 340 and 344 these are intermittent circuit codes for the intake cam on bank1 (Pass side). with after market cams sometimes the reluctor on the back of the camshaft is bent which creates a lapse in reading at the sensor.”

Sounds like I’m going to have to bust into the engine.

 

[TrackGT]

Update: I upgraded to a 200A alternator and the codes went away. I have yet to recreate the issue after a few hard drives. Hallelujah!