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Chris(aka-Moose)
Chris(aka-Moose), Nissan Technician
Category: Nissan
Satisfied Customers: 615
Experience:  16 years of experience
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Altima 2002 2.5L loss of spark after a few seconds of

Customer Question

altima 2002 2.5L loss of spark after a few seconds of cranking, had been having random misfires on highway, then couldn't get past 1700rpm and now won't start. Both cam and crank replaced several times, bough 10 sensors, all tested good, got real nissan sensor, they are worse. hooked up oscilloscope, I can see signal coming out of both sensors nice and sharp when probing at the computer. Tried another ECU but can't get it to fire at all in that config. email me at***@******.***
JA: Does the vehicle stall at low speeds? Does it sputter?
Customer: does not start at all
JA: Are you fixing your Altima yourself? What have you tried so far?
Customer: yes DIY, already listed above
JA: Anything else you want the mechanic to know before I connect you?
Customer: this is a common issue on 2002-2006, everyone has faulty cam/crank sensors it seems, but my sensors work just fine. I hooked up a logic analyzer to sensors and spark output, when cranking you can see spark fire on all cylinder but the spark signal coming out of the ECU goes away after a few crank rotation. It doesn't go away all at once but instead the ECU sends fewer and fewer of them until none. Battery voltage good. Tried with all coils disconnected, probing ECU spark output, I get the same thing, spark signal firing then disappears.
Submitted: 7 months ago.
Category: Nissan
Expert:  Jay replied 7 months ago.

Hello my name is ***** ***** thank you for your question.

Do you know if you have any codes?

Customer: replied 7 months ago.
I did this check back in Dec 2015 . Current codes might be different.Current Fault Log
------------------
P3100: Unknown code - More information may be available on the webPending Fault Log------------------
P0031: HO2S Heater Control Circuit Low (Bank 1 Sensor 1)
P0011: "A" Camshaft Position - Timing Over-Advanced or System Performance (Bank 1)
Expert:  Jay replied 7 months ago.

Do you have a scanner or a code reader?

Customer: replied 7 months ago.
what I just sent you is the output from it.. can you see the list of code I just sent?
Customer: replied 7 months ago.
Hello,
When I got home I hooked up my scanner again and took three more readingsThe first reading was AS IS. Tests I have performed over the past year no doubt triggered faults.
Here it is
--------------------------------------------------------------------------------------------------------
Fault log report generated by Torque for Android
=================================================Vehicle VIN:
Vehicle Manufacturer:
Vehicle Calibration ID:Current Fault Log
------------------
P0340: Camshaft Position Sensor "A" Circuit (Bank 1 or Single Sensor)Pending Fault Log
------------------
C0000: Unknown code - More information may be available on the web
C0003: Unknown code - More information may be available on the web
P0031: HO2S Heater Control Circuit Low (Bank 1 Sensor 1)
P0340: Camshaft Position Sensor "A" Circuit (Bank 1 or Single Sensor)Historic Fault Log
------------------
ECU reports no historic faults
Other discovered fault codes
(possibly pending, current or manufacturer specific)
----------------------------------------------------
ECU reports no other fault codes loggedEnd of report.
--------------------------------------------------------------------------------------------------------Then I cleared the codes and took a second reading, no fault reported this time--------------------------------------------------------------------------------------------------------
Fault log report generated by Torque for Android
=================================================Vehicle VIN: Not present
Vehicle Manufacturer: Unknown
Vehicle Calibration ID: 18J000
ICurrent Fault Log
------------------
ECU reports no current faultsPending Fault Log
------------------
ECU reports no pending faults
--------------------------------------------------------------------------------------------------------So next I tried starting the car a few times and then checked for codes--------------------------------------------------------------------------------------------------------
Fault log report generated by Torque for Android
=================================================Vehicle VIN:
Vehicle Manufacturer:
Vehicle Calibration ID:Current Fault Log
------------------
ECU reports no current faultsPending Fault Log
------------------
C0000: Unknown code - More information may be available on the web
P0340: Camshaft Position Sensor "A" Circuit (Bank 1 or Single Sensor)Historic Fault Log
------------------
ECU reports no historic faults
Other discovered fault codes
(possibly pending, current or manufacturer specific)
----------------------------------------------------
ECU reports no other fault codes loggedEnd of report.
--------------------------------------------------------------------------------------------------------While I was cranking I took a small video
You can see it here
https://youtu.be/YrK04aXNh6o
You can hear the engine pickup and then die after a few revolutions
Expert:  Jay replied 7 months ago.

Thank you for that. On your Cam Sensor, does it have this logo on it? Also is the Crank Sensor OEM as well?

https://dl.dropboxusercontent.com/u/105565483/Cam%20Sensor%20OEM.jpg