'09 Coupe w/ 90k - Problem with ECU/ECM?
 

CEL Code: P0174 (Bank 2 MAF) - Bank 2 = the driver's side MAF. I have already tried swapping the passenger's side MAF with the driver's side MAF and it still wasn't fixed. Next I purchased a new MAF for the driver's side and that still didn't fix it.


At 90,000 miles my 2009 G37x Coupe began experiencing a very strange intermittent problem. The car would buck and jerk as if it were slamming into gear a bunch of times as I was cruising down the freeway at ~45 MPH with the RPM's shakily climbing up and down the gauge. I say it's intermittent because it only happens approx. once every 2 weeks. When the bucking/jerking/slamming into gear/feel like i'm going to go fly through the window superman-style any second/ feeling happens I usually put the hazard/caution lights on and pull off to the side of the road otherwise it is NOT drive-able AT ALL and i'm pretty sure something more expensive could break if I don't (i.e. the tranny). So after pulling over the RPM's will always go up and down erratically on their own between 900-1200 RPM's (Car Normally IDLEs at warm-up at 600 RPM's) shut the car off and wait for the computer to power down (count to 10) then I start it up and the RPM's are normal back to 600 RPM's again like nothing ever happened?! This has happened to me over 40 times this past year no joke and I just had the wiring harness to the ecm replaced (500$ part) but it didn't fix it.

Also, when this happens it usually doesn't give me a CEL or any lights or codes or anything, however, sometimes it has (P0174) and when it has it was the CEL, VDC, and SLIP lights all at once. That's when I would not only shut it off but before turning it back on I would reset the ecu by:

1. Ignition On count to 3
2. depress/release pedal 5 times
3. count to 10 and full depress pedal
4. count to 12 (ses blinks)
5. count to 10 depress pedal
6. count to 10 release pedal
7. turn off ignition and restart the car

Video of the problem:
Any ideas/suggestions/anyone heard of this sort of problem?

Get yourself a code reader from autozone. They're usually about $30 for a basic reader keep it in the car and the next time the CEL light comes on rather than reset the ECU find out what the code is...

You can then post the code here or look it up

Infiniti OBD-II Trouble Codes

It was P0174 (Bank 2 MAF) - Bank 2 = the driver's side MAF. I have already tried swapping the passenger's side MAF with the driver's side MAF and it still wasn't fixed. Next I purchased a new MAF for the driver's side and that still didn't fix it.

The exact same problem is happening to me. Any idea as to what it is?

Well, I've tried switching and then replacing the MAF sensor, I've replaced the wiring harness to the ECM, sent the computer out to a computer repair specialist but they didn't have the tools to fix it, and am now in the process of getting the dealer to see if they can update the ECM to see if that will fix it (maybe it's a glitch and the computer needs an update?) I honestly have no idea and was hoping some tech guru here would be able to shed some light?

Please let me know if you solve it & how you did so! It's very frustrating!

Will do. It sucks I know, I never thought I'd have a car problem like this it's very odd and definitely frustrating!

Have you ever cleaned your throttle bodies? I watched your video and was having the same spoaradic idle issues on my '08 minus the CEL coming on. I cleaned the throttle bodies and replaced the o-ring seals per the DYI on the forum. Now she purrs perfectly at approx. 650 RPM every time. Might be worth a shot and at almost 100,000 miles I'm sure they're pretty grimy. Hope it helps.

Could be a major vacuum leak somewhere along bank 2 -- technically, could be a leak anywhere from intakes to just past primary O2 on bank 2.

On that note, although you didn't get a code for it, it could be a problem with the bank 2 primary O2 or a bad connector on the MAF, meaning sensor would be fine, but wires would be bad.

IIRC, there is a TSB for a ECM reburn for this. . .

Maf issues
 

I have a 09 g37x coupe, I am having the exact same issue you had, I'm hoping you found out what your issue was, I cleaned both MAF sensors and it was good for a few months, then it came back. I replaced both MAF sensors and it was good for 2 weeks, happened again today. Any information would be great

Did you check the plug the maf plugs into