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Discussion Starter · #1 ·
So my engine service light popped up earlier...had a friend run the code and it was


Camshaft position A/Bank 1 circuit malfunction....how much is this going to run...i was planning on do a big car maintanence to begin with just not this soon..

2002 mustang GT
 

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Chances are your cam position sensor (CMP) is just bad. It is a small sensor mounted on the front of the timing cover behind the power steering pump. It isn't very expensive at all.
 

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its behind the ac pump. it is a cheap senser and is easily damaged. its nothing more than a magnet so it can pick up and matalic shavings in your motor and make it register wrong. to replace it pull the serp belt off and back out the 3 bolts holding the ac in place. there is a single bolt holding the crank shaft position senser in the timing cover.
 

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its behind the ac pump. it is a cheap senser and is easily damaged. its nothing more than a magnet so it can pick up and matalic shavings in your motor and make it register wrong. to replace it pull the serp belt off and back out the 3 bolts holding the ac in place. there is a single bolt holding the crank shaft position senser in the timing cover.
He's got a bad Cam sensor, but yeah, they are the same type of sensor and should be pretty cheap.
 

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oh my bad, i read it totaly wrong, if its the cam shaft positons senser its behind the power steering resivor. also that check engine code pops when a alternater is going bad. not sure why but it does
 

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oh my bad, i read it totaly wrong, if its the cam shaft positons senser its behind the power steering resivor. also that check engine code pops when a alternater is going bad. not sure why but it does

I have heard that too. Maybe it has something to do with RFI/EMI emitted as the alternator is failing causing a messed up CMP signal.
 

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I got this code last week and it turned out the rectifier group in my alternator went bad. Is your car stumbling upon startup? Hopefully it's just a faulty CP sensor but it doesn't hurt to have your alternator bench tested before you replace anything.
 

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I have heard that too. Maybe it has something to do with RFI/EMI emitted as the alternator is failing causing a messed up CMP signal.
The signal from the cam position sensor is connected in series with one of the alternator wires. So if the alternator goes, the PCM stops reading the bank 1 CMP sensor. P0340 I think it was.
 

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Discussion Starter · #9 ·
I got this code last week and it turned out the rectifier group in my alternator went bad. Is your car stumbling upon startup? Hopefully it's just a faulty CP sensor but it doesn't hurt to have your alternator bench tested before you replace anything.
After i ran the code from my friends reader i went to start...and it didn't start up the first time...2nd time did it again nothing...third time it started after i cranked it
 

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The signal from the cam position sensor is connected in series with one of the alternator wires. So if the alternator goes, the PCM stops reading the bank 1 CMP sensor. P0340 I think it was.
Makes sense. Maybe the alt uses the signal from the cmp as an input to control the voltage regulator.
 

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Yeah the exact same thing happened to me and I ended up wasting $50 on a new cam sensor to find out the diodes in my alternator were broken
 

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Discussion Starter · #14 ·
Just replaced it today! $150 including labor....but its back to normal so I am a happy camper

thank you all who helped and reps!
 

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Discussion Starter · #15 ·
ok probably celebrated to early....service engine light came on again later in the day and what do you know IT WAS THE SAME PROBLEM so either A) they guy never put in a new sensor B) its my alternator...

either way im pissed off
 

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Ouch, sorry to hear that man. it's pretty simple to install an alternator, you were slightly overcharged on the cam position sensor, so if I were in your position, I'd order an alternator from ebay or Advance Auto and bolt it on myself.
 

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Yikes! you need to learn how to work on a car lol I'm a total noob and I was able to swap the cam sensor myself, its just a quick unbolt of the PS res and there it is. That was not a $150 job. But yeah I think EVERYONE with this issue tries the cam sensor before getting the alternator done in hopes of saving money but like 99% of the time it seems to be the alternator lol. Like stated, either get a new one or just have yours repaired if it's cheaper. They're very easy to install and uninstall, all the bolts are visible
 

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Discussion Starter · #18 ·
Yikes! you need to learn how to work on a car lol I'm a total noob and I was able to swap the cam sensor myself, its just a quick unbolt of the PS res and there it is. That was not a $150 job. But yeah I think EVERYONE with this issue tries the cam sensor before getting the alternator done in hopes of saving money but like 99% of the time it seems to be the alternator lol. Like stated, either get a new one or just have yours repaired if it's cheaper. They're very easy to install and uninstall, all the bolts are visible
going to go back tomorrow and have them do it for free...well i hope they fix it for free because the job was not done right
 

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Discussion Starter · #19 ·
Yikes! you need to learn how to work on a car lol I'm a total noob and I was able to swap the cam sensor myself, its just a quick unbolt of the PS res and there it is. That was not a $150 job. But yeah I think EVERYONE with this issue tries the cam sensor before getting the alternator done in hopes of saving money but like 99% of the time it seems to be the alternator lol. Like stated, either get a new one or just have yours repaired if it's cheaper. They're very easy to install and uninstall, all the bolts are visible
looks like your 99% of the time its the alternative was right....i have a faulty diod in my alternator...and for the sake of convenience i went ahead and had my mechanic order one for me and i will be getting my car back tomorrow
 
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