# Blinking malfunction light



## creektrails (Jan 31, 2011)

I was driving today at highway speed 75 to 80 and the light started blinking for a bout 5 seconds or so and then went out. It continued to do this all the way home. (about an hour and a half coming on and going off) I took it to a parts store and they plugged it ina and they said that nothing had tripped a marker. 
I noticed it would start blinking as I was going down hills. never going up when the motor was under stress. and when I got to the city the light went out and stayed out. I never noticed any problems, missing etc.
I recently changed rear brakes, oil change and air filter change. Its and 02 2.5.
any suggestions?


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## smj999smj (Jan 1, 2006)

When the CEL starts flashing, it indicates a problem that could cause catastrophic damage to the catalytic converter. Often this indicates a misfire, such as an ignition coil failing. It should have, at list, left a history code. Not knowing the capabilities of your part's stores diagnostic tool, I can only suggest you have the trouble codes checked by an independant shop or Nissan dealer with a more sophisticated scantool.


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## creektrails (Jan 31, 2011)

smj999smj said:


> When the CEL starts flashing, it indicates a problem that could cause catastrophic damage to the catalytic converter. Often this indicates a misfire, such as an ignition coil failing. It should have, at list, left a history code. Not knowing the capabilities of your part's stores diagnostic tool, I can only suggest you have the trouble codes checked by an independant shop or Nissan dealer with a more sophisticated scantool.


would the suggestion in the sticky about using the gas peddle to find the code, work? THe guy in the post had the larger motor and i didnt know if that method worked on my car?
Secondly, would nt the light come on and stay on if there is a potentialy catastophic problem. I would think even if the problem was temporary that they would design it to stay on if it was a major problem.


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## creektrails (Jan 31, 2011)

this morning i got in the car and the instrument panel power was gone. I started to drive my daughter to work and the rpm llimiter must have kicked in. The car would lose all power at a certain rpm but I didnt know what it was because the instrument panel was out.
I took it to a mechanic and he took three numbers out of the computer and is going to call me when he looks them up. w'ell see.


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## jdg (Aug 27, 2009)

Sounds like it went into that "fail safe" mode where not a lot of stuff works and the engine will only work so hard before powering itself back.
That info is in the FSM's.
VVVVVVVVVVV


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## chimmike (Oct 17, 2002)

what's the oil level? that's the first thing I'd check.

sounds like something is either seriously wrong, or a major sensor is screwing up. 

Definitely in failsafe mode though.


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## creektrails (Jan 31, 2011)

I just changed the oil. I did use 4 1/2 quarts though. What would the oil have to do with it?


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## chimmike (Oct 17, 2002)

what is the oil level? You may have just changed it, that's good and fine. But what is the level? 

02 QR25's had a terrible problem with precats breaking up, getting sucked back into engines and causing major oil burn problems.


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## creektrails (Jan 31, 2011)

It is right at the top mark. Just before the high H letter.


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## creektrails (Jan 31, 2011)

These are the codes he found and the description he gave me. U 1001 he said that is a : can line communication hard code 
and the second one was : T0650 which is a ECM code

My mechanic said that I probably need to go to the dealership to have it followed through. Anyone familiar with these? Im going to look them up on google.


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## smj999smj (Jan 1, 2006)

The P0650 is for the MIL circuit. Possible causes is an open/shorted MIL circuit or the lamp, itself. If the ECM detects a problem with this circuit, it will set the code and put the vehicle into fail-safe mode. Circuit consists of 10A fuse #14 in the fuse block, the wire from the fuse to the bulb, and the wire from the bulb to the ECM. 

The U1001 code is a CAN communication problem for the ECM. Possible cause is shorted/open harness or connectors. I'm assuming the two codes are likely related. One of the first things I'd check is the ground points for the ECM and battery cable connections. Might as well check the fusible links, too. ECM grounds were subject for a TSB pertaining to a U1000 code setting in 02-06 Altimas, but without the drivability issues you're experiencing. If those are ok, I would next disconnect the battery negative cable and unplug the ECM harness connector. Check for bent pins and corrossion and correct, if necessary. Plug-in the ECM, reconnect the battery cable and start the vehicle. See if the problem is fixed. If not, then I would suspect an issue in the harness somewhere or a faulty ECM. This would be a lot easier to trace with a Nissan Consult II scantool due to the CAN (controlled area network) system used in your vehicle. The fact that the MIL circuit is throwing a code and the gauges don't work would make the harness connection at the back of the integrated meter assy. suspect.


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## creektrails (Jan 31, 2011)

smj999smj said:


> If those are ok, I would next disconnect the battery negative cable and unplug the ECM harness connector. Check for bent pins and corrossion and correct, if necessary. Plug-in the ECM, reconnect the battery cable and start the vehicle. See if the problem is fixed. If not, then I would suspect an issue in the harness somewhere or a faulty ECM. This would be a lot easier to trace with a Nissan Consult II scantool due to the CAN (controlled area network) system used in your vehicle. The fact that the MIL circuit is throwing a code and the gauges don't work would make the harness connection at the back of the integrated meter assy. suspect.


Thanks for the great info. Is the ECM under the seat? And second where is the integrated meter assly? Is that where the instrument panel pllugs in? Please overlook my novice ingnorance.


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