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2005 FX45 120K miles
186 Posts
Discussion Starter · #1 · (Edited)
Many Gen-1 FX45/35 owners are reporting their starter will not engage on the first key-turn. And some are also saying they are able to start their engine after waiting 3-15 minutes. So what's up with that?

When this happened to my 2004 FX45, I checked for Diagnostic Trouble Codes (DTC) and I did not have any. So now what? Well, I took my new to me FX to the dealer and they said I need a new starter. However, I had not done my research and they wanted to make an appointment in 2 weeks so I I told them I would let them know another day; and I am glad I did, because that was over 1.5 years ago, and I'm still using my old starter, which is not known to go out BTW.

Next, I bought a Lithium jump pack and I highly recommend you do as well.


First, the fact your starter will engage (click) but will not start the engage, this is your first clue.
It might suggest you might have a dead battery, but if you have no reason to think so; and you did not leave any interior lights on overnight; and your headlights were not left on either; then in these FX's it's more likely one of these other problems will result in a fix.

1) The Body Control Module (BCM) may not be authorizing power to your ECM which then authorized the starter.

2) Maybe your IDBM fuse box, next to the battery, blew a fuse or you need to clean your fuses.

3) In cold climates, owners report they replaced their Air Conditioning Amplifier (AC Amplifier) located under the radio.

4) I warm climates, where I live, I found all I had to do was to clean the fuses located next to my emergency brake. These fuses protect the AC Amplifier and the BCM. So, I'm guessing if cleaning them fixed my no-start condition then there must be a drain on the BCM or a weak ground.

Why did this work for me? Well, maybe, the door locking system has something to do with the drain. I think this might be possible, because my door locks would not work in hot weather (above 90F) and sometimes they would not work after I repeatedly pressed the fob buttons.

The the BCM controls these functions, but the drain I speak of is coming from the door actuator; or more specifically, the PTC-R inside the door actuator, which is a 50-cent device that acts like a auto-reset-fuse. And when it get old it has a tendency to leak current to ground. And this first causes your BCM to malfunction or it can drain your battery.

Note: Repair shops will tell you you have to replace your door actuator, which is expensive. DIY owners (with skills) will take the door actuator out and just replace the motor inside, which houses the PTC-R. It's not a fun job. And I would say it takes more experience than replacing a simple window motor. But when the dealer charges $800/door to do it for you, that's a whole lot of motivation.

First, I would clean the fuses next to your emergency brake and see if that fixes your problem like it did for me.

NEXT: If you are having problems with an intermittent no-engine-start in cold weather, there are a number of people who have fixed this no-start problem by replacing the Air Conditioning (AC) Amplifier box that is located under the radio. Note: Each FX model has a different AC-Amplifier part number based on how your car came equipped from the factory, so finding the right AC-Amplifier (used) maybe a problem. That being said, I would remove the AC-Amplifier... open the box... and look for a cold soldier joint you can fix for $0 if you own a cheap soldier iron; or you can take the AC-Amplifier to a local stereo or satellite repair shop that will charge you $50 to diagnose your components "at the board level," which means they don't need a schematic.

Attached is a summary of where you can find several fuse boxes in you car. And for some strange reason, Infiniti put a number of fuses right next to your battery, which makes these fuses and relays hard to get to.

Also, if you starter turns your motor over, but your engine will not start, then maybe you need to replace your Hitachi brand Crank Position Sensor... located under you engine, on the passenger side, behind that bottom skid plate.



This cigarette lighter has a USB charge port and voltmeter ($10)

or this one with FM+bluetooth for hands-free cell phone use:

Schumacher SL1639 Lithium Portable Power Pack and 1000A 12V Jump Starter, for 8.0L Gas | 6.0L Diesel Engines – Jump Start Car, (60% off too!)

Attachment: 2003 – 2008 Fuse Diagram FX45


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