# P0340 & P0650 Codes



## GadgetBoySI (Apr 13, 2009)

2003 Altima L31 - 3.5L Engine

Driving the car Saturday and it was pouring outside. Car stalls for no apparent reason. Starts up after engine cranks for 5-10 seconds. All seems well from that point forward.

Take the car home. Next morning car starts, no problem. Start to drive. At about 2500 RPM, the car begins bucking. Slow acceleration, no problem. Give it a little more gas, at 2500 starts bucking again. Turn around and head back home.

Back at the house. Check ODB code and get P0340 AND P0650 (MIL Indicator).

I am assuming perhaps this wasn't caught sooner because of the P0650 lamp. Car is obviously no longer under warranty. Does it sound like this just a cam position sensor or is it something bigger? I was going to pick up the sensor today and replace it; it just seems like the bucking engine could be an indicator that it could be something worse.

Thanks in advance,
GB


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## Nickaltima (Jan 11, 2008)

Can you smell raw fuel out of the exhaust? b/c my 03 3.5 5spd had the same problem a year ago..and it was the MAF sensor


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## GadgetBoySI (Apr 13, 2009)

Ok. So this happened again on my way home tonight. This time it kicked out P0442 and P0650 codes. The car was bucking at 2500 RPM.

I reset the codes and the car is working fine. There are no more codes being thrown.

Does this make sense?


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## jdg (Aug 27, 2009)

(just a couple of the hits I found)...
P0650 Malfunction Indicator Lamp Control Circuit - Nissan Forums : Nissan Forum

Malfunction Indicator (MIL) Control Circuit P0650? - Yahoo! Answers

Sounds like you've got a bad driver in the ECM itself. Maybe something along the lines of trying to open (or close) a solenoid, but it can't.


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## GadgetBoySI (Apr 13, 2009)

The last time this happened it was a crankshaft sensor, but at the time, I didn't even attempt to reset the code. 

The wife drove the car last night with no issues. It still seems to be throwing the P0650 code somewhat regularly. Sounds like no matter what, I should look to address that by swapping the ECM. Is this something I should stick with the manufacturer on, or can I get away with OEM, used, etc.?

Thanks for the response.

Any other thoughts from other peeps?


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## jdg (Aug 27, 2009)

This engine/vehicle combo isn't my specialty by any stretch...so I'm throwing things out there as general info and basically babbling...
The P0650 code doesn't appear that it's a MIL indicator specific code, more it's an ECM specific code. It also looks like this code could possibly be tripped by bad wiring outside of the ECM itself.
Since you've also got a P0442 (small evap leak) and the P0650, I'd be looking at solenoids related to the EVAP system, e.g. EVAP canister solenoids, possibly EGR solenoids, etc.
The P0442 could be caused by something as simple as a loose gas cap, so I'd check that out first, possibly swap the cap out (from another car if it fits, what the heck, practically free check).
At the same, time, when the light is on, you've got bucking/spitting/bad-running above 2500 rpm. Seems like I remember a bad MAF will cause the engine to limit itself to ~2,000 rpm or so.
I think the best thing you can do is make the problem appear in a repeatable fashion, e.g. figure out what kind of driving makes the light come on. At least then, you can start to narrow down the problem without throwing parts at it and wasting $$$. ECM's aren't cheap...or maybe they are. Guess it depends on where you get 'em.


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## GadgetBoySI (Apr 13, 2009)

Thanks jdg.

Strange this is that the check engine light never comes on. Last time, the bucking was caused by either a crankshaft sensor or cam sensor (don't recall off the top of my head). I swapped the sensor out and the car has run fine since.

Oh, and the P0442 has not returned since I reset it. Perhaps it was a gas cap thing - until yesterday I hadn't hooked the ODB tool up to the car in a long time.

I will be taking the car for a 100 mile trip today - hopefully all is well with it - I will be bringing the OBD tool with me. ;-)


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## smj999smj (Jan 1, 2006)

The P0650 indicates a problem with the circuit that illuminates the "MIL" lamp. The circuit runs from 10 amp fuse #14 in the fuse block, through the combination meter MIL lamp and then to the ECM, which grounds the circuit. If a code sets in addition to the code, the ECM puts the vehicle in "fail safe" mode, which limits the engine to 2500 RPM. The best thing to do would be to follow the FSM procedure for this code to check the circuit to the ECM. If the circuit and combination meter prove good, then the ECM is at fault and will need replacing. If the ECM does need replacing, you will likely need the services of your Nissan dealer. The keys will have to be re-initialized in order for your vehicle to start, accelerator and closed throttle position will need to be relearned, and idle air volume will need to be learned. The software may also need to be updated. An ECM costs $715 (Nissan MSRP) for the part, alone. Labor should be 1.1 hours to replace and reset/reprogram it per labor guide times, but I can see a dealer bumping that time to 2 hours. A bad ECM could cause stalling and multiple codes to set.


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## GadgetBoySI (Apr 13, 2009)

I'm sorry - FSM - Factory Service Manual?


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## smj999smj (Jan 1, 2006)

Yes--FSM: Factory Service Manual


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