P1078 comes back after replacing exhaust cam sensor

[mek88]

Hi Infiniti lovers,

My 09 fx35 with160k miles showing p1078 code. Ive replaced it with original Denso part# GF30+GB20 exhaust cam sensor the rear top bank1-passenger side. I cleared the code, but few seconds later it came back. Any suggestion? Thanks

[VStar650CL]

Check to make sure you have 5V between Red and Blue and Yellow and Blue at the connector. Blue should be an ECM ground, Red is the 5V supply, and Yellow is the data line pulled up to 5V by a resistor inside the ECM. If the voltages check okay, make sure there isn't a bunch of magnetic debris on the cam reluctor (stick a pencil magnet in the hole and have an assistant turn the balancer by hand two full rotations to move the camshaft). If all of that pans out, your new sensor is probably DOA.

[mek88]

Could the crank sensor at the lower engine location caused this issue? Thx

[VStar650CL]

Not likely. Missed teeth on the CKP will sometimes fool the ECM into blaming a wrong component, but it's typically an IVT and not an EVT. Both TPS's, CMP B1, power steering pressure, and one of the APP's are all on the same 5V bus with EVT B1, so it isn't likely to be a global power outage either. Short of scoping the EVT signal, you could try back-probing Yellow and the same wire on the other EVT with the engine running. The voltages should be very nearly identical, if they aren't then you probably have an issue with wiring or pin-fit (or your new sensor is DOA).

[VStar650CL]

PS - Dropping any Hall sensor on the floor is almost guaranteed to mess it up magnetically, and parts stores aren't always careful about handling. We even see that with OE parts, the guys in Nissan's Memphis warehouse can be both brutal and careless about packaging. So don't ever be surprised about a DOA Hall sensor. Stuff happens.

[mek88]

I just realized that ive been replacing the intake cam sensor instead of exhaust sensor on the lower of bank 1. So finally i changed the exhaust sensor and p1078 is now gone. ….However., now p0011 and p0021 showing up! Which sensor now? Thx

[VStar650CL]

P0011/P0021 aren't usually electrical when they occur together, they mean the intake cam timing is off on both banks. The ECM would have been running "fixed" cam timing due to the P1078, which is why the IVT codes are only showing up now. The most common cause of P0011/P0021 is low oil or incorrect viscosity, but in general it means either an oil pressure problem in the front cover or sloppy timing chains.