[smileifuh8]

My 03 Nissan Sentra GXE 1.8 has problems with cold start and it drives bad for 2-3 min but after that its okay...
Yesterday is was +5C and had the same problem in the morning
And the SES light went on, gave me the code 340(not sure, have to check when im home)
I checked this forum and changed the cam and crank shaft sensor with original parts from nissan...
Car wont start
But if i put the old sensor in, it starts...
Who can help me?
Im in canada and the winter gets really cold here, so its a problem in the winter time..

Sorry for my English, its my third language and im still learning

 

[i68k]

P0340 - Camshaft Position Sensor 'A' Circuit Malfunction

seems you have a bad cam sensor. was that the only code you have? its def the cam sensor, or connection to the cam sensor. other problems would be battery terminals and grounds for tightness and contact, and voltage motor on&off? else, follow the trouble diagnosis for the cam sensor in the fsm, free download for fsm. it shows which pins and wires to check for voltages, and shows tolerances.

 

[smileifuh8]

Its the only code i had...
Sorry but whats the fsm?

But why is my car not starting if i change both?

 

[JudoJohn]

maybe the new sensors were bad.

FSM is factory service manual.

 

[i68k]

you can download the fsm for free
fsm = Factory Service Manual

http://allsentra.com/fsm/ -the cam sensor stuff is in electrical motor control section.


if that was your code, the cam sensor is what the ecu is telling you is the problem. its possible you got a defective piece brand new? exchange it for another one if it doesnt work. you should be using the newer metal type cam sensors. its look like a metal cylinder.

check the connector on the cam sensor see if it was dirty, dont forget to push the connector on until it clicks on.

 

[smileifuh8]

Thank you for the fsm, i will check it out
When i got the parts from nissan, i got the old Plastik ones.. I knew about the newer metal one, but the guy said thats for my car...
I check other stors or online for a metal one

Btw:
When i install the new sensor, my car acts like i disconected the cam sensor, it cranks but wont start

 

[i68k]

it might be defective, its always a possibility.

you can follow the troubleshooting steps in the fsm to diagnose the issue. it shows where to get voltages and if theres continuity, etc. all for the cam & crank sensors. if its not the sensor itself, it could be the wiring or connection to the ecu.

 

[smileifuh8]

got 3 new sensor and still same problem...
was reading on a diffrent forum, that some people fixed it with shiming the valve cover...
what do you guys think?

 

[i68k]

not sure what the valve cover has to do with your cam sensor? your valve cover should be rtv'd down so it doesnt leak. not sure why you would shim your valve cover, its pressurized and should be sealed tight.

well, if your following the fsm, step 2 is checking your grounds on the timing cover for good contact. you should also check your battery terminals for tightness and good ground contact. check your battery voltage with motor on&off.

step 3 is check the wire harness for the cam sensor on the left side of the valve cover, you should read battery voltage.

step 5 is checking the input signal, assume you checked this and it was good?

if you get to step 9, and youve identified the cam sensor is functioning properly and all your voltages/connections were good, you need to follow the basic electrical troubleshooting section.