Let’s start from the beginning. 2006 Silverado. L33 , slightly worked over. Forged rods/pistons. Low lift BTR stage 2 truck cam. 799 heads ported and polished. TBSS intake. Headers, dual exhaust., x pipe. 4L60E. 342 gears. Here is where it gets interesting. Put about 7,000 miles on the motor. Experienced what I thought was transmission concerns Due to Certain high performance enthusiasts in close circles advising me that the 4l60E would go soon. No shift. So I had my local guy eyeball it and scan it. He found nothing. He surmised it was mechanical. and Diagnosed a failed transmission. I was a somewhat prepared and yanked the 4L60E out. Primary thought was to put a 4lL80 and forget about the myth of the 4L60e. I found an old ‘papi’’ that was well trusted around town with 30 years building transmissions. He recommended I keep the 4L60e and let him work it over. So I purchased a rebuild kit from pro- built automatics. 2600 stall from Edge racing. While the truck was down I purchased a rear end rebuild kit. Detroit tru-track and 373 gears. Slapped the transmission in. Motor would not turn over.no biggie, turned my attention to the rear end. Opened the dif cover and found the spider in pieces. Turned out it was not the transmission at all. The culprit was the rear end. Sent out the rear end to a specialist. got it back in 2 weeks. Put the rear end back, still no start. Towed the truck to diagnostic shop they diagnosed tarnished connectors and bad ground. Got it running but the P0342 code was present and causing mis starts and misfires. My mechanic insisted it was a tune issue. I forced him to check the cam sensor. He found I frayed cam sensor connector wire being pinched by the transmission. Replaced the cam shaft position sensor connector Sent it out to a tuner. The tuner street tuned it and dialed in the transmission and rear end, but advised me that I had mis starts and misfires associated with P0342 code. He asked me about what reluctor wheel I had. I told him the it wasn’t touched since the last time I had him tune it. It still had the 24 tooth reluctor wheel. He said it was definitely the cam sensor. On the way home, experienced low oil pressure message and the hose from transmission cooler sprang a leak. Now, next day after….. fixed the hose. Still dealing with p0342 code and now a low oil pressure and the oil pressure needle will not budge. When I shift the column shifter it seems to skip or delay the shift icons on the dash. Not trying to drive it with no oil pressure to see if it goes through gears mechanically. My mechanic say it might be a harness issue. Any ideas?

 

P0342 is Camshaft Position (CMP) Sensor Circuit Low Voltage here is a information on the code straight from GM The camshaft position (CMP) sensor works in conjunction with a 1 X reluctor wheel on the camshaft. The powertrain control module (PCM) provides a 12-volt reference to the CMP sensor as well as a low reference and a signal circuit.

As the camshaft rotates, the reluctor wheel interrupts a magnetic field produced by a magnet within the sensor. The sensors internal circuitry detects this and produces a signal which the PCM reads.

The CMP sensor 1 X signal is used by the PCM to determine if the cylinder at top dead center (TDC) is on the firing stroke or the exhaust stroke. The PCM can determine TDC for all cylinders by using the crankshaft position (CKP) sensor 24 X signal alone. The engine will start without a CMP signal as long as the PCM receives the CKP sensor 24 X signal. A slightly longer cranking time may be a symptom of this condition. The system attempts synchronization and looks for an increase in engine speed indicating that the engine started. If the PCM does not detect an increase in engine speed, the PCM assumes that the PCM incorrectly synchronized to the exhaust stroke and re-syncs to the opposite cam position. If the PCM detects that a CMP signal is constantly low, DTC P0342 sets.
Have you hooked any form of obd scanner to it yourself? Is the code current or passed and history? As for the low oil pressure the sending unit in 99-07 gms are notoriously terrible I would check the oil pressure with a mechanical gauge before I did anything else just to rule out any internal engine damage. Seeing as the oil pressure sender and cam sensor are next to each other on a gen 3 I would look to see if maybe there isn't another section of the harness pinched in the bellhousing? Also does your tach read as that references the cam sensor I believe.

 

Thanks for responding. Very informative breakdown.I’ve personally scanned it myself and cleared the code. It just pops up again. I will perform a pressure check before I move on to anything else and keep you posted. The tach instrument panel needle is stuck on zero and does not budge at all. I also briefly saw a p1810 pressure switch manifold . But cleared that and it hasn’t returned.

 

Ok so if your your tach is not reading then it sounds to me like you have a issue with the cam sensor signal circuit. The P0342 indicates that the issue is on the signal wire but it could be issue with the 5 volt reference or low reference but I would start with the signal circuit. I have seen GM engines run with no cam signal under certain circumstances I guess at a point the crank sensor takes over and provides the ECM a engine speed signal. I would start by checking to see if maybe you have pinched the harness that runs along the back of the valley in the bellhousing.

 

I’ve seen the curse of the PO342 code on this forum before. I needed a step by step guide on how to diagnose any probabilities. I am by no means e technician in any regard. So your breakdown again was helpful for the sake of understanding. My initial build was from a recipe I borrowed from on all cylinders. My mechanic, as knowledgeable as he is, really doesn’t deal much with performance stuff. He is a good friend of mine. He installs on average one motor a week. Ranging from Ford transits to Ford 6500. Ram sprinters etc. for the past 20+ years. My engine builder told me to get a terminator X and make my life easier. As I mentioned before my mechanic advised that my harness looked shady. I hope it is harness related and not mechanical. All the sensors, cam, crank sending unit, oil level sensor, pickup tube, melting 295 standard oil pump, MAP, MAS, knock sensor, LS 2 timing chain…. They are all as new as the motor with roughly 7000 miles. The only things that was released was the harness and Crank, but that was machined. I tried to save a few dollars by not purchasing what my builder advised.