Thread: P0340
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Old 12-12-2019, 11:10 AM   #2 (permalink)
Ghostvette
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Quote:
Originally Posted by Knio View Post
Hi all,

Just going to dump my problems here...

Driving home the other day, everything seems fine until the freeway onramp when I lose all power. It feels like the fuel starvation problem that I've experienced before, and I am low on fuel.. so I coast off the freeway, and eventually it gets some power back, but it's extremely jerky and definitely not a fuel starvation problem now.

I limp back to a parking lot. The idle is not smooth and bouncing between 800-1400, and it won't rev past 3.5k at all. When I tested revving it, TCS and slip lights also come on. I turn the engine off, try to turn it back on, it will crank but not fire.

Eventually I get a code reader working and see P0300 and P0340 - Camshaft position sensor error. Check the forums and see a few posts that mention unplugging the sensors might work. I clear the DTCs and try it:

Both sensors plugged in - won't start

Bank 2 unplugged - won't start

Bank 1 unplugged - will start, but cranks for much longer than normal, and is in limp mode and won't rev past 3.5k, but the idle is smooth, and everything feels fine otherwise! This has been reproducible every time.

I swapped the left and right sensors, both looked clean and the problem is still exactly the same, and not P0345, and still runs with only bank 2 plugged in, so I think both of the sensors themselves are working.

I probed all connections with a multimeter at both harnesses for OC, SC, and the signal, at the sensors themselves, and in the ECM harness and everything looks fine, and the left & right banks match, giving more evidence that it's not a sensor or electrical problem. I don't have a scope, but the signals are 5V when off and jump around near 4.5V when the engine is running, which is what you'd expect from working sensors.

I feel like I've eliminated any electrical problems, and could it really be a timing problem since the engine runs fine and smooth up to 3.5k in limp mode? But will keep looking.. I've ordered a scope to check the actual signals, and will try to remove the timing cover to inspect the camshaft gears and timing chain this weekend. Most of the other threads I saw didn't post resolutions. I'm hoping I can fix this myself and not have to take it to a dealer :P

Car is tuned with JWT intakes, Nismo exhaust, oil cooler, 60k miles.

Other threads:

Z throw P0340 and P0345 code after violent spun out on skidpad
Car won't start & pending Code P0340
2009 base won't start
Help me diagnose this problem: I can't rev past 3500 RPM intermittently (AK370Z)
Camshaft/Crankshaft Sensor, Limp Mode, Z issues :/
Need Help - Car Stalled and wont start
When a problem doesn't move side to side, then the problem is usually wire/ECM related. Try removing the negative terminal from the battery, step on the brake pedal for 10 to 15 seconds (I don't remember exactly, there is a thread somewhere) to clear memory, then reattach cable. Try restarting the car and see what happens with both sensors plugged in. I doubt you have a timing chain issue, the car wouldn't run at all if it jumped time. If you have access to a good scanner (snap-on, MAC or Consult), that might help. GL.
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