Hi all,

So I've made a few posts here so far and after hearing advice and scouring the forums, I've made some progress on my car. However it's still giving me some problems, so before I cave in and take it to a dealer I'll lay all the issues out here and see if anyone could help me diagnose it before I spend the big bucks and take it in.

-I purchased a 2005 Infiniti G35 Automatic Coupe w/ 114,XXX miles. Looked clean, drove nicely. On the way home from the dealer when I was on the highway doing about 65mph, the car lurched forward like the gears had slipped, then resumed driving as usual. Weird.
-When I turned on the headlights, the climate control lights began flickering. I assumed this was due to a weak alternator.
-When I parked the car and went to turn it on an hour later, it didn't start. The lights on the dash lit up and the radio popped on, all the accessories worked, but it didn't crank. Not even a click. I also noticed that the gear display on the dash was blank instead of showing "P". I let the car sit for five minutes and went to start it again. This time it started right up.
-I then noticed the "Check Engine" light was on. The only codes displayed were U1000- CAN communications error, and a code for a bad fuel level sensor (the fuel gauge doesn't work).
-When I drove the car the next morning, it displayed "D" on the gear display for drive. Suddenly while going about 40mph down a local road, the car jerked forward, RPMs shot from around 2500 to 4500-5000 and the gear display went blank. I panicked, hit the brakes, the car lurched again, RPMs dropped to normal, the "D" showed back up on the dash. It drove normally for another five minutes, then jerked again and the "D" disappeared. This time it didn't reappear and when I went to accelerate from a stop sign, it took forever to accelerate. Felt like I wasn't actually in a gear for about 7 seconds. When the jerking occured, my "A/T CHECK" light flashed for a few minutes. The light went away when the gear displayed itself again at the dash.
-When I parked the car, it still didn't show a gear display. I turned it off, and went to turn it on a few hours later. It didn't start, same situation as before. Waited about 10 minutes this time before the gear display finally flickered to a "P" and the engine turned over.
-I then checked my battery terminals for a loose connection. The positive top post terminal was so rusty it almost broke off, so I replaced the post and cleaned all the connections. I also replaced the negative battery terminal/ ground cable and cleaned the ground connections that went to the chassis. This didn't clear the check engine light, although I hoped it would.
-The next day I drove it to work with minimal issues, but when I went to leave for the day, surprise, the engine wouldn't crank. It continued to not show a gear. Waited ten minutes, tried again, nothing. I became frustrated and continued to try every couple minutes, nothing helped. Eventually a click could be heard when I was trying to start the engine. I assumed my starter had failed. I had to have the car towed as it didn't start, only clicked for about an hour.
-The next morning I went to remove the starter so I could purchase a new one. On a whim I decided to check my IPDM and swap the Starter relay with the Headlight Low relay. After doing this, it started right up. The headlights surprisingly worked too- and it stopped the flickering of the dash. It didn't make sense to me but I was happy not to have to replace the starter.
-When driving it that day, the jerking and gear display going blank happened at least once every two minutes. It was so bad that I was scared to drive and ended up turning around and parking it in my garage. Surprise, when I tried to turn it on again, it didn't start.
-I began to research possibilities. Transmission position sensor, camshaft sensor, crankshaft sensor, bad transmission, bad starter, bad ECU, bad TPM, you name it. I was overwhelmed with possibilities. I ended up going and removing my throttle body/ air intake entirely to try and search for bad sensor connections. I didn't get very far without a diagram so I went to put the pieces back together and find a diagram. When I did so I forgot to reconnect the harness for the MAF sensor. I started the engine and the SLIP and VDC OFF light came on with the usual lights. I scanned it and found 3 codes: P0101 Mass or Volume Air Flow Sensor "A"Circuit Low P0113 Intake Air Temperature Sensor 1 Circuit High Bank 1, and P0462- fuel level sensor circuit "A" low. The first two codes were new, and my constant U1000 communications code was gone. I was confused until I remembered I hadn't replugged the MAF sensor harness. After doing that, I started it up, and suddenly all codes besides the fuel sensor were cleared! I couldn't believe it. It started up every time and drove just fine the next day, I only took it around town. It continued to start every time and drive perfectly- no gear flickering, no jerking, nothing. Until I got brave and decided to take it on the highway on my way home tonight. Since it had been doing so well I figured it would be fine. Bad move. It drove fine, but as soon as I got home, I turned it off. I had to move the car about 5 minutes later to make room in my driveway, but when I went to start it- you guessed it, IT DIDN"T SHOW A GEAR, AND WOULDN'T CRANK.

I am beyond frustrated now. I waited for it to show a gear again and then started it and parked it in my garage. Currently I have the throttle body and air intake removed and have sprayed the MAF sensor and connections with MAF cleaner. I also removed the negative battery cable and am letting it sit like that for 12 hours tonight. I don't know what to do at this point- I can't narrow down what this issue is. It could be purely coincidental that it only occured again after driving at freeway speeds, or that it cleared out after reconnecting the MAF in the first place. Does anyone have any tips/advice that could help me out before I go take it to a dealer? I really don't want to spend that kind of money for more guessing games on this car....

 

Stop messing with your MAF sensor. That doesnt seem to be the issue.

My money is on one of your ECU's crapping out. Or something being wet/flooded.

 

Do you notice any water or evidence of water by your ecu and tcm? I'm wondering if you have/had a water issue and the connections are corroded or modules are going bad.

 

Update: I went through and cleaned all the grounds in the engine bay that I could find. I mean I took them apart, filed them down, sprayed it clean, etc. This seemed to fix the problem as I went about a week with no error lights, no starting issues, and no gear slippage.

However I went through a car wash yesterday and decided to whip a couple donuts right after. I parked my car after doing the donuts to get a few pictures of it, tried to start it a few minutes later and it didn't display a gear on the dash and wouldn't crank. This time I immediately disconnected the battery and let it sit for an hour. Re connected it, and it started right up, has been fine since. I'm wondering why it did that? Maybe related to harsh movement, a loose wire, etc?

 

I'm pretty sure the instrument cluster has a ground. Maybe someone can confirm this

 

remove IPDM check and clean all connections relays and fuses