How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site. Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Matt Your Own Question
Matt, Engineer
Category: Infiniti
Satisfied Customers: 21885
Experience:  Honors degree in Mechanical Engineering, worked 8 years as a Formula 1 engine engineer.
Type Your Infiniti Question Here...
Matt is online now
A new question is answered every 9 seconds

Bought an 08 g35x that had been overheated and warped or

Customer Question

Bought an 08 g35x that had been overheated and warped or cracked head so I replaced with salvage yard 08 long block. Installed but now nothing happens when pushing start button, shows a U1000 code, yellow key light comes on, seems like in general strange things are going on with the electronics. Not sure remote is communicating properly or maybe ECU issues. Car did sit for weeks with dead battery. Have double checked grounds. Remote will lock and unlock doors. Wondering if I need ECU or remote reprogramed? Any ideas?
Submitted: 11 months ago.
Category: Infiniti
Expert:  Matt replied 11 months ago.


to get the U1000 code is a lack of communication between modules and is usually a security issue where the key module isn't allowing the car to start

I'd 1st check all the small ground connections in the engine bay as there should be a couple of ring terminals that run out of the wiring loom and are secured to the engine with a small bolt

if this is OK then check that you're getting 12V in the engine bay fusebox on the ECU and fuel pump module fuses with the ignition on

if not then yes its quite possible the key will need recoding to get it all to sync up again

Customer: replied 11 months ago.
OK I checked grounds and replaced the battery in the fob. When I pushed the button to start nothing happened. Then about 5-10 seconds later it started on its own! Engine sounds good so I let it run for about 10 minutes. Radio and climate controls worked. I noticed when I opened the door it would cut power for a second but not long enough to kill the engine. When I pushed the button to turn off nothing happened. Ended up having to disconnect alternator wire to kill engine. Seems like a communication issue with the security system. I was not able to get to start again after we got it shutoff. Does this sound like I need the fob reprogrammed and if so is it done by dealer only or is their another way? Thanks
Expert:  Matt replied 11 months ago.


thats progress

try this fob re-sync process

1 Sit in the driver's seat and close all doors. Lock all of the doors using the power lock switch on the driver's door.
2 push start button (do not start the car) at least six times in 10 seconds. The start button must be pushed on and off fully each time. If you have done this step successfully, the hazard lights will flash.

3 Push the start button to the "accessories" setting.
4 Press any button on the remote within five seconds of putting in the key. If you have done this correctly, the hazard lights will flash again. That remote is now programmed into the system.
5 Unlock and then lock all doors using the driver's-side lock switch. Press any button on a new remote within five seconds to program that remote in to the system. Repeat this step for every remote, including any existing remotes that were programmed before this procedure.
6 Turn the ignition to the "Off" position to end the programming mode and unlock the doors using the driver's-side power lock button and open the driver's door.

Customer: replied 11 months ago.
Ok, I need a little clarification, this is a 2008 that does not have an ignition to put a key in so when you talk about pressing any button within five seconds of putting the key in I'm not sure if you mean the door or if you are thinking that their is an ignition to put a key in or maybe the docking station for the remote? And turning the ignition to the off position at the end. Thanks
Expert:  Matt replied 11 months ago.


the remote fob should have buttons on it? those are the ones I mean when I say to press any button

Customer: replied 11 months ago.
Right, but what am I putting the key in ?
Expert:  Matt replied 11 months ago.

sorry thats a typo

step 4 should read

press any button on the remote within 5 seconds of pressing the start button

Customer: replied 11 months ago.
I tried the the re-sync process with no luck. I also had a local lock shop come out and make sure the fob and car are in sync. They reprogrammed the key and it did not help as well. Car still starts randomly when trying to get it to start but will not shut off on its own. You have to open and close the door to get the accessories to come on and still getting the U1000 code. Car will run and drive when it starts. The Yellow key still lights up and the red car with the key in it flashes. Any other ideas? The closest Infinity dealer is 400 miles away and the local Nissan dealer does not work on them. Thanks
Expert:  Matt replied 11 months ago.


this is sounding like a fault with the body control module to me

I'd say the next step is to locate the BCM and disconnect it and clean the connectors on both sides with switch / contact cleaner

also check over the wiring to the module for insulation damage

if this is all OK then I'd consider replacing the module or have it sent off for repair

this forum post has a lot of informaiton about doing this

and these repair shops should be able to help