Help with code P0342
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Pro
Joined: Jan 2005
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From: CORNELIA GA
Help with code P0342
My car keeps giving the code P0342 Camshaft Position (CMP) Sensor Circuit Low Voltage. Now I have to cycle the car three times before it will crank. Has anyone had this problem before, and how did they fix it. Have CMP Sensor order from GM, hasn't came in yet. JOHN
Burning Brakes
Joined: Feb 2001
Posts: 892
Likes: 1
From: Houston Texas
Ok......you have 1 of 4 problems. You dont have to cycle the car 3 times, just keep turning it over and it will eventually start.
1. Camshaft position sensor is bad. Pray thats it but they very rarely go out.
2. Wiring that goes from sensor to PCM is bad. (short, broke, etc. Can be checked by running a continuity check from the plug that goes into the sensor to the big plug on the PCM)
3. The reluctor wheel on the camshaft is bad (probably not the problem)
4. And the winner and most pain in the *** isssss? the 3 bolts that connect the cam gear to the camshaft have come loose which would cause the cam to slide aft which causes the reluctor wheel on the rear of the camshaft to not line up with the sensor anymore.
I was having your problem which was happening to the second engine that was put in my Z06 under warranty and after I had about a 1000 miles on it. I had already had the supercharger installed and the dealership changed the first engine under warranty because of a defective camshaft (another story). I ran continuity checks on the wiring and checked the sensor and it all checked good. I went ahead and changed the sensor for the hell of it and that didn't fix it. I then had the ECM computer replaced under warranty and then had to get it reprogrammed for my supercharger, but that didn't fix the problem either. The only other alternative was to check the cam. So I pulled the radiator, steering rack, etc. and when I got to the timing cover off I could see what the problem was. All 3 bolts that attach the cam gear to the cam had come loose and backed all the way out to where the bolt heads were rubbing on the timing cover and even the alignment pin that aligns the cam gear to the cam was gone, which I later found when changing the oil because it was stuck to my magnetic oil drain plug. Anyway, this caused the cam to move aft which prevented the reluctor wheel on the back end of the cam from lining up with the cam sensor. This was when my engine was completely stock internally. So the f**king idiot moron who assembled the engine from the factory didn't tighten all the bolts nor did he use loctiite. Anyway, I got new bolts, gaskets, cam, timing cover, and cam gear from the dealership for free because my car was all under warranty. Anyway, since I had it all tore apart, I installed an aftermarket cam, double roller timing chain and put it all back together and never had another problem out of it.
And to make a long story short, they didn't want to work on my car under warranty on the second engine because they said the supercharger caused internal damage. I knew that was BS because the supercharger has no effect on the cam whatsoever and this engine only had 1000 miles on it. Once I had the engine apart and showed the worn bolts, cam gear, and timing cover to the manager at the dealership, he agreed with me that it wasn't my nor the superchargers fault and gave me all new parts for free.
The cam position sensor is only used for starting purposes. Once the engine is started, the reluctor wheel on the crankshaft provides position timing for the computer. The reluctor wheel on the cam has 2 notches that are 180 degress opposite of each other. The cam position sensor has a magnetic pickup that reads these notches. If the cam position sensor is unable to "see" these notches, then you will experience longer than normal engine cranking because the computer is trying to determine when to start the firing sequence and get a code and so on.
There is a way to check the sensor. I think its called a (duty cycle or % duty test, something like that), anyway, it will tell you if the sensor is good or not, the service manual talks about it. You will need a multimeter that can perform that type of test. You can also do a continuity check on the wiring from the cam position sensor plug down to the ECM on the frame at the passengers front fender well. If that checks good, then the only thing left is the cam.
1. Camshaft position sensor is bad. Pray thats it but they very rarely go out.
2. Wiring that goes from sensor to PCM is bad. (short, broke, etc. Can be checked by running a continuity check from the plug that goes into the sensor to the big plug on the PCM)
3. The reluctor wheel on the camshaft is bad (probably not the problem)
4. And the winner and most pain in the *** isssss? the 3 bolts that connect the cam gear to the camshaft have come loose which would cause the cam to slide aft which causes the reluctor wheel on the rear of the camshaft to not line up with the sensor anymore.
I was having your problem which was happening to the second engine that was put in my Z06 under warranty and after I had about a 1000 miles on it. I had already had the supercharger installed and the dealership changed the first engine under warranty because of a defective camshaft (another story). I ran continuity checks on the wiring and checked the sensor and it all checked good. I went ahead and changed the sensor for the hell of it and that didn't fix it. I then had the ECM computer replaced under warranty and then had to get it reprogrammed for my supercharger, but that didn't fix the problem either. The only other alternative was to check the cam. So I pulled the radiator, steering rack, etc. and when I got to the timing cover off I could see what the problem was. All 3 bolts that attach the cam gear to the cam had come loose and backed all the way out to where the bolt heads were rubbing on the timing cover and even the alignment pin that aligns the cam gear to the cam was gone, which I later found when changing the oil because it was stuck to my magnetic oil drain plug. Anyway, this caused the cam to move aft which prevented the reluctor wheel on the back end of the cam from lining up with the cam sensor. This was when my engine was completely stock internally. So the f**king idiot moron who assembled the engine from the factory didn't tighten all the bolts nor did he use loctiite. Anyway, I got new bolts, gaskets, cam, timing cover, and cam gear from the dealership for free because my car was all under warranty. Anyway, since I had it all tore apart, I installed an aftermarket cam, double roller timing chain and put it all back together and never had another problem out of it.
And to make a long story short, they didn't want to work on my car under warranty on the second engine because they said the supercharger caused internal damage. I knew that was BS because the supercharger has no effect on the cam whatsoever and this engine only had 1000 miles on it. Once I had the engine apart and showed the worn bolts, cam gear, and timing cover to the manager at the dealership, he agreed with me that it wasn't my nor the superchargers fault and gave me all new parts for free.
The cam position sensor is only used for starting purposes. Once the engine is started, the reluctor wheel on the crankshaft provides position timing for the computer. The reluctor wheel on the cam has 2 notches that are 180 degress opposite of each other. The cam position sensor has a magnetic pickup that reads these notches. If the cam position sensor is unable to "see" these notches, then you will experience longer than normal engine cranking because the computer is trying to determine when to start the firing sequence and get a code and so on.
There is a way to check the sensor. I think its called a (duty cycle or % duty test, something like that), anyway, it will tell you if the sensor is good or not, the service manual talks about it. You will need a multimeter that can perform that type of test. You can also do a continuity check on the wiring from the cam position sensor plug down to the ECM on the frame at the passengers front fender well. If that checks good, then the only thing left is the cam.
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Pro
Joined: Jan 2005
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From: CORNELIA GA
Originally Posted by Av8ter
Ok......you have 1 of 4 problems. You dont have to cycle the car 3 times, just keep turning it over and it will eventually start.
1. Camshaft position sensor is bad. Pray thats it but they very rarely go out.
2. Wiring that goes from sensor to PCM is bad. (short, broke, etc. Can be checked by running a continuity check from the plug that goes into the sensor to the big plug on the PCM)
3. The reluctor wheel on the camshaft is bad (probably not the problem)
4. And the winner and most pain in the *** isssss? the 3 bolts that connect the cam gear to the camshaft have come loose which would cause the cam to slide aft which causes the reluctor wheel on the rear of the camshaft to not line up with the sensor anymore.
I was having your problem which was happening to the second engine that was put in my Z06 under warranty and after I had about a 1000 miles on it. I had already had the supercharger installed and the dealership changed the first engine under warranty because of a defective camshaft (another story). I ran continuity checks on the wiring and checked the sensor and it all checked good. I went ahead and changed the sensor for the hell of it and that didn't fix it. I then had the ECM computer replaced under warranty and then had to get it reprogrammed for my supercharger, but that didn't fix the problem either. The only other alternative was to check the cam. So I pulled the radiator, steering rack, etc. and when I got to the timing cover off I could see what the problem was. All 3 bolts that attach the cam gear to the cam had come loose and backed all the way out to where the bolt heads were rubbing on the timing cover and even the alignment pin that aligns the cam gear to the cam was gone, which I later found when changing the oil because it was stuck to my magnetic oil drain plug. Anyway, this caused the cam to move aft which prevented the reluctor wheel on the back end of the cam from lining up with the cam sensor. This was when my engine was completely stock internally. So the f**king idiot moron who assembled the engine from the factory didn't tighten all the bolts nor did he use loctiite. Anyway, I got new bolts, gaskets, cam, timing cover, and cam gear from the dealership for free because my car was all under warranty. Anyway, since I had it all tore apart, I installed an aftermarket cam, double roller timing chain and put it all back together and never had another problem out of it.
And to make a long story short, they didn't want to work on my car under warranty on the second engine because they said the supercharger caused internal damage. I knew that was BS because the supercharger has no effect on the cam whatsoever and this engine only had 1000 miles on it. Once I had the engine apart and showed the worn bolts, cam gear, and timing cover to the manager at the dealership, he agreed with me that it wasn't my nor the superchargers fault and gave me all new parts for free.
The cam position sensor is only used for starting purposes. Once the engine is started, the reluctor wheel on the crankshaft provides position timing for the computer. The reluctor wheel on the cam has 2 notches that are 180 degress opposite of each other. The cam position sensor has a magnetic pickup that reads these notches. If the cam position sensor is unable to "see" these notches, then you will experience longer than normal engine cranking because the computer is trying to determine when to start the firing sequence and get a code and so on.
There is a way to check the sensor. I think its called a (duty cycle or % duty test, something like that), anyway, it will tell you if the sensor is good or not, the service manual talks about it. You will need a multimeter that can perform that type of test. You can also do a continuity check on the wiring from the cam position sensor plug down to the ECM on the frame at the passengers front fender well. If that checks good, then the only thing left is the cam.
1. Camshaft position sensor is bad. Pray thats it but they very rarely go out.
2. Wiring that goes from sensor to PCM is bad. (short, broke, etc. Can be checked by running a continuity check from the plug that goes into the sensor to the big plug on the PCM)
3. The reluctor wheel on the camshaft is bad (probably not the problem)
4. And the winner and most pain in the *** isssss? the 3 bolts that connect the cam gear to the camshaft have come loose which would cause the cam to slide aft which causes the reluctor wheel on the rear of the camshaft to not line up with the sensor anymore.
I was having your problem which was happening to the second engine that was put in my Z06 under warranty and after I had about a 1000 miles on it. I had already had the supercharger installed and the dealership changed the first engine under warranty because of a defective camshaft (another story). I ran continuity checks on the wiring and checked the sensor and it all checked good. I went ahead and changed the sensor for the hell of it and that didn't fix it. I then had the ECM computer replaced under warranty and then had to get it reprogrammed for my supercharger, but that didn't fix the problem either. The only other alternative was to check the cam. So I pulled the radiator, steering rack, etc. and when I got to the timing cover off I could see what the problem was. All 3 bolts that attach the cam gear to the cam had come loose and backed all the way out to where the bolt heads were rubbing on the timing cover and even the alignment pin that aligns the cam gear to the cam was gone, which I later found when changing the oil because it was stuck to my magnetic oil drain plug. Anyway, this caused the cam to move aft which prevented the reluctor wheel on the back end of the cam from lining up with the cam sensor. This was when my engine was completely stock internally. So the f**king idiot moron who assembled the engine from the factory didn't tighten all the bolts nor did he use loctiite. Anyway, I got new bolts, gaskets, cam, timing cover, and cam gear from the dealership for free because my car was all under warranty. Anyway, since I had it all tore apart, I installed an aftermarket cam, double roller timing chain and put it all back together and never had another problem out of it.
And to make a long story short, they didn't want to work on my car under warranty on the second engine because they said the supercharger caused internal damage. I knew that was BS because the supercharger has no effect on the cam whatsoever and this engine only had 1000 miles on it. Once I had the engine apart and showed the worn bolts, cam gear, and timing cover to the manager at the dealership, he agreed with me that it wasn't my nor the superchargers fault and gave me all new parts for free.
The cam position sensor is only used for starting purposes. Once the engine is started, the reluctor wheel on the crankshaft provides position timing for the computer. The reluctor wheel on the cam has 2 notches that are 180 degress opposite of each other. The cam position sensor has a magnetic pickup that reads these notches. If the cam position sensor is unable to "see" these notches, then you will experience longer than normal engine cranking because the computer is trying to determine when to start the firing sequence and get a code and so on.
There is a way to check the sensor. I think its called a (duty cycle or % duty test, something like that), anyway, it will tell you if the sensor is good or not, the service manual talks about it. You will need a multimeter that can perform that type of test. You can also do a continuity check on the wiring from the cam position sensor plug down to the ECM on the frame at the passengers front fender well. If that checks good, then the only thing left is the cam.
Melting Slicks
Joined: May 2004
Posts: 2,502
Likes: 4
From: cincinnati ohio
4. And the winner and most pain in the *** isssss? the 3 bolts that connect the cam gear to the camshaft have come loose which would cause the cam to slide aft which causes the reluctor wheel on the rear of the camshaft to not line up with the sensor anymore.
I have seen this myself personally on several occassions, good luck !!!
I have seen this myself personally on several occassions, good luck !!!
