the infamous "cam position sensor" code NEED HELP!!!

ok so i have a 2005 mustang gt. about 2 months ago i poped a check engine light. 2 codes came up, one was for cam position sensor bank 1 and the other was cam position sensor circuit intermittent bank 1. ive already replaced both of the freakin sensors (ran me abou $26 a pop) and the codes still there.
the car itself under low throttle and rpms under 2k, every once and a while itll jerk forward like i just tapped the gas hard. the rpms will slightly rise with the jerk. other than the phasers possibly getting worn out but the engines stock with a steeda proflow cai and muffler deletes. i cant figure it out and im wandering if anyone has a better idea than i do. holla back!
 
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bigb427

Member
Nov 3, 2010
128
2
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Las Vegas, NV
Ford has a TSB for this concern which has you check the alternator diode pattern using an oscilloscope. A faulty alternator can cause excess RFI which reaks havoc with the PCM.
Since you already replaced the CMP sensor on bank 1 (passenger side), I'd say it's a good bet the the alternator is your problem. If you're a gambling man replace the alternator, otherwise take it to the dealer and have them test it properly.
It is also possible the VCT on bank 1 could be malfunctioning, but the car would be running pretty bad if that were the case. I doubt this is the cause of your concern.
 

bigb427

Member
Nov 3, 2010
128
2
19
Las Vegas, NV
If the alternator has a major failure NAPA and other parts stores would find that easily. However they are not equipped or trained to do in depth testing as called for in the TSB I mentioned which would give you a definitive answer as to whether your alternator is the cause of your problem or not.
To the best of my knowledge the dealer is the only place that has the people trained AND the proper equipment to test the alternator in the exact manner which is called for in the TSB.
 

MADSCOTSMAN

New Member
Feb 22, 2010
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Had the exact same issues, threw cam position sensor codes, car would stutter sometimes at highway speeds almost as if it was loosing fuel pressure. Replaced the alternator and battery and the issues went away about a year ago.
 
These guys are hitting it dead on the head. Had the cam shaft position code and replaced it twice only to have the check engine light disappear until I took it on the highway. Then it was right back to sputtering. That code also says that it could be the timing chain but your car would handle so much more rougher that it is now. Read on some forums that it was a failing alternator and gave it a try. Fixed the problem and hadn't had a issue since.
 

Skarlet2005

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Jun 17, 2015
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New to site ... Found this thread via google and it helped me a lot! Thanks!!! I have a 05 Mustang GT - got a code for camshaft position sensor (340) - changed it out - cleared engine code - code came right back when I jumped on highway next day. Went and tested my battery and alternator. Battery good, alternator bad. Replaced alternator and code cleared on it's own, car is no longer "bucking". Now ... I'm having another issue since I switched out alternator two days ago ... hoping y'all may have some advice.

When I don't have clutch pushed in and/or I'm out of gear, my car drops down to like 300-400 rpms ... feels like it's going to die me but doesn't. If I'm just sitting, idling, the rpms stay right around 900-1000. I've never had an issue like this. No engine codes and car is running great except when I come to a stop. Really strange. Any ideas?
 

TROY TURNER

New Member
Aug 18, 2016
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Yep, these codes were driving me nuts, changed both sensors, swapped them around, put oem ones back in, nuthin. It also it must effect the TPS also, my car had a strange, intermittent stumble, like when cruising for a long time with the cruise on then downshift & stand in it to pass someone, then it would stumble.

Swapped in a brand new alternator, all problems gone!!
 

racerraj

Founding Member
Dec 17, 2001
471
29
39
Dickson, TN
Alternator fixed mine too. Just as a side note, I tested the alternator while it was in the car at Autozone, and the test they ran did say the diode was bad. Pretty sure most parts places can test the alternator in the car and the test also tests the diode.
 

Usmcdevildog

New Member
Apr 14, 2017
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HELP ME PLEASE !! I'm gonna blow this car up!!

I'm getting the same codes as OP, position sensor and intermittent, I've changed both sensors and the alternator!! I clear the codes and start and drive it runs GREAT!! Until it gets warm then boom engine light comes back on same codes get thrown and the car runs like crap at low rpms, it's not to bad if your above 2500 can someone please help me I'm gonna lose it.. 2005 mustang gt 100,000 miles.
 

racerraj

Founding Member
Dec 17, 2001
471
29
39
Dickson, TN
I'd guess (only a guess) the cam phaser is bugging out once the oil gets warm. Or the cam phaser solenoids. Possibly the timing chain sensor. When it is running bad, can you hear the chain slapping around in the timing cover? If so, only on one side, or both? Does it throw any codes?
 
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Usmcdevildog

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Apr 14, 2017
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Yes I can here something slapping but only after it gets warm I don't understand it, if the thing is smooth and quiet when cold why is it running so rough when warm yes it throwers those same codes. I clear them drive it and the same codes come back but only after it warms up.. can I post a video and would that help?
 

racerraj

Founding Member
Dec 17, 2001
471
29
39
Dickson, TN
If you hear the slapping, that is the timing chain slapping. And I would guess it is because the cam phaser is bugging out, or the timing chain tensioner isn't keeping enough tension on the chain at idle. Or the solenoid that controls the cam phaser isn't working right with hot oil. A video wouldn't help me zero in on which of those items, but a good timing kit includes all but the solenoid. They are around $400 to $500 I think. A cheaper kit ($200ish) doesn't include the phasers. You may be ok just replacing the phaser and solenoid too if you know which side is making the noise. The solenoid is easy, but the phaser is a bit more work. You could try the solenoid first, they are around $60 I think.