My_Fingers_Hurt

I have a 2008 G37 Sport (5AT) with 71,000 miles that was running rough. I checked the codes and it said P0305, which is a misfire in cylinder #5. Driving to the dealership for repair, the SES light came on. The dealership says the plugs and coil look good, but the injector shorted out, which shorted out the ECM. It's going to cost $2200 to fix. Does this sound right? I didn't know an injector could short out the whole ECM. How does this happen with only 71,000 miles?!

slartibartfast

iTrader: (7)

My_Fingers_Hurt

I've got it at the shop right now, so I don't know how they were able to diagnose it. They told me that they checked the plugs and the coils, all of which were fine. All I know is that the injector shorted which shorted the ECU. The car has been absolutely flawless before this. I'm the second owner and I bought it CPO from a dealer back in 2011. I'm so disappointed.

slartibartfast

iTrader: (7)

SonicVQ

^^^ Yes! Fuse 44 would of blown if any of the fuel injectors were shorted.

Ask the shop for the freeze frame data (short/long term fuel trims for each bank) from when the p0305 was declared.
If a fuel injector was shorted, the fuel trims will be VERY different from bank 1 to bank 2.

My_Fingers_Hurt

Talked to the shop today and they're saying I need a new ECM. When I noticed the misfire, I had the codes checked and the only codes were P0305 (Cyl #5 misfire) and P1815 (Manufacture Mode Switch Circuit). I looked at the factory service manual for the P0305 misfire code and it says nothing about a faulty ECM.

Wouldn't a faulty ECM throw its own code, like P0603 or P0605 or something? Not just P0305?

bythabay

iTrader: (2)

Kirbydyson23

Sprry for reopening a dead thread but did this fix the problem? I am having the same issue. I am a mechanic and came to this diagnosis on my own with my own $5000 scan tool and after opening the entire wire harness up and finding nothing. I actually did get a P0603 code after changing the head gasket and I just want to make sure there wasn't any other factors involved that could be causing the issue that I am missing. There is no fuel delivery but the fuel pump is fine. Did what they did fix your issue or was there more to it? Also just curious what did they charge you to change the injectors on this car? I can take thosr injectors off in less than 20 minutes and swap them out and the ECU takes maybe 10 minutes to remove at most. I just want to know what the dealerships are charging in labor for an easy job like this (not counting diagnosis time). Thanks and sorry again for opening a dead thread up. It is the only one I found where someone had the same issue.