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Engine power reduced

Tiny
MECHANICALIDIOT
  • MEMBER
  • 2005 CHEVROLET COBALT
  • AUTOMATIC
  • 120,000 MILES
When driving my car it will stall I have had a code reader hooked up I got P0340
P0601.
Any advice on what I should do? I have been told to disconnect the battery but I do not have a wrench set.
Thursday, February 1st, 2018 AT 6:02 PM

11 Replies

Tiny
STEVE W.
  • MECHANIC
  • 13,035 POSTS
Without tools you are very limited. The P0340 is a cam position sensor failure.
The P0601 is a code meaning the powertrain control module has an internal problem.
The P0601 can be caused by a bad ECM or if the voltage going to the computer is low from a bad connection or bad wire.
For both you need a scan tool and a DVOM. If you do not have them a shop you trust would be the best solution.
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Friday, February 2nd, 2018 AT 10:47 PM
Tiny
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  • 15 POSTS
I was informed that the camshaft sensor is usually the primary cause of the codes would you recommend changing them?
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Friday, February 2nd, 2018 AT 11:28 PM
Tiny
STEVE W.
  • MECHANIC
  • 13,035 POSTS
Not without actually testing the voltage to the ECM first to see if that is causing the P0601 or if the ECM is actually faulty.

Which engine do you have? The 2.2 or the 2.0 with the supercharger? That will make a big difference as to the P0340 code.
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Saturday, February 3rd, 2018 AT 7:05 AM
Tiny
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I am unsure, but I am pretty sure it is the 2.2.
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Saturday, February 3rd, 2018 AT 7:53 AM
Tiny
STEVE W.
  • MECHANIC
  • 13,035 POSTS
Sorry I took so long. The reason I asked is that the 2.2 doesn't use a common cam sensor. It actually uses circuitry inside the coils to detect the burn events in the cylinder. This code can be set if that circuitry is faulty. The ECM low voltage could also be set if there is a coil that is shorting and pulling the system voltage low.
Not something that is easy to find without a scan tool and a scope to check the signals from the coils and checking the voltage to the ECM.
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Thursday, February 8th, 2018 AT 5:45 PM
Tiny
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I just changed out the cam sensor and the problem is still going and we test the voltage im getting and im at 15.2 VDC we also tried to see if it was a fuse still happened. Do you think it could the altenater not properly limiting the power and causing the pcm to turn off so nothing gets overvoltage
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Thursday, February 8th, 2018 AT 6:04 PM
Tiny
STEVE W.
  • MECHANIC
  • 13,035 POSTS
OK you have the 2.0 then? It has an actual cam sensor. 15.2 wouldn't be an issue if it's after starting up. What is the battery voltage with the engine off? If it's staying at 15.2 all the time then you have a problem. That could be PCM related though as the P0601 is set if the PCM gets low voltage. If there is a problem between the PCM and the alternator/battery and it thinks you have low voltage it could be trying to raise the voltage up.
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Thursday, February 8th, 2018 AT 7:29 PM
Tiny
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Its a 2.2L I should have said cam synthesizer but its a steady 15.2-15.4 voltage even when its running and I believe it stayed even when off
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Thursday, February 8th, 2018 AT 7:53 PM
Tiny
STEVE W.
  • MECHANIC
  • 13,035 POSTS
Check the voltage with the engine off, A lead acid battery should produce 12.6 volts for a full charge. 15 volts will kill it in short order. A good scan tool should be able to see that voltage and see what the PCM is measuring the voltage at. It sounds like the regulator is being run very high by the PCM. The thing to figure out is why. It's possible the checksum error is related to the overcharging, but the only way to be sure would be to test the voltage at the PCM. Then swap it for a new one.
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Friday, February 9th, 2018 AT 12:08 AM
Tiny
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  • MEMBER
  • 15 POSTS
We figured it was most likely the voltage regulator in the altenator so we were going to check it by using jumping my car from my buddies car to see if it lies at the battery then go further
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Friday, February 9th, 2018 AT 12:21 AM
Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 43,264 POSTS
Please let us know what you find. We are interested to see what it is.

Cheers, Ken
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Monday, February 12th, 2018 AT 11:43 AM

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