Car comes in with a P1390 Cam/Crank Correlation code and note about adding coolant recently.
The Neon 2.0 doesn't have timing marks on the front cover. You guess at cylinder 1 TDC using a rod through the spark plug hole. Then look through a small hole to line up the marks on the camshaft.
So I decided to take a few minutes and scope the camshaft sensor and crankshaft sensor first.
As I pull connector 1 on the PCM. I'm greeted with what looks like coolant in the plug cavity.
Not good, at least the PCM didn't short.
On to the cam crank correlation.
It looks... OK? No signal dropouts or weird glitches.
Thanks to Fred Wilson. Cam signal is shifted to the right and cam gear was off one tooth.
I'd expect the cam signal (green) to be shifted more to the right or left if it were off.
I'm having trouble finding a known good pattern to compare to.
Can anyone provide a known good cam/crank correlation pattern?
If the pattern is good and effectively rules out timing, what are some other causes of a P1390 code?
Coolant in the PCM plug cavity could definitely be a contributing factor.
As I was doing the correlation I noticed coolant leaking from the timing cover.
So if I get confirmation I'll be tearing apart the front of the engine and will be able to confirm the correlation. As well as the source of the leak, most likely a water pump.
Tore apart the front of the engine today. Forgot to get a picture of the cam gear, the locator pin was fine and the cam gear was off one tooth.
To bad the front cover is hidden behind the front mount/power steering/tensioner plate.
The car now has a new water pump, tensioner belt and cam gear locator pin.