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So my FX45 had an intermittent starting issue for a while now. It’ll start right up whenever I first turn it on that day, but then won’t start at all after a few short trips. It won’t crank at all, almost like the starter is bad. But the weird thing is that it will start again roughly 30 minutes later without any hesitation.
The starter that came on the car when I bought it had died completely about two months ago, so I changed that out for a second hand starter. That worked fine, but that introduced the intermittent starting issues. Some days I could go three of four small journeys without having it refuse to start, other times I could only make it one journey. About a week ago it would refuse to start at all, but I was able to get it running for another five days or so by hitting the starter whilst somebody turned the key, I did this up until Monday when my remanufactured starter arrived.
Now this new starter should work great, all of the internal components are new and it has a warranty, so I’m not worried about getting it replaced if there’s a problem, but after three starters I’m thinking there has to be something else to it. What could be causing this?
This new starter is also giving me the same problems, it’ll start in the morning no problem and will let me restart it again after one or two journeys, but then won’t start again for quite a while. Hitting it also doesn’t seem to have any affect.

The battery is two months old, and is very strong, it’s not a better problem. The wires looked just fine when I was replacing the starter, so I don’t believe it’s a wiring issue, at least not the wires directly connected to the starter. What else could it be?

 

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Hey friend! Dealing with the exact same issue right now. Have heard that the issue might be caused by the driver wheel position due to wear on wires from years of it moving on entry and exit. I did find that moving the wheel all the way in (towards the engine) and up would sometimes allow the car to start. But not always, and more recently I’ve found that just by turning the key to on, waiting 10 seconds, and then turning to start would allow the car to start. It’s puzzling, and seems like it could be the alarm system over riding it, or something similar because when my car does start, it does so with ease. My next plan is to replace the AC controller, I can’t recall exactly the name, but it’s a white plastic box that lives under the CD changer in the stereo. Hope one of us finds a solution!
 

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Hey friend! Dealing with the exact same issue right now. Have heard that the issue might be caused by the driver wheel position due to wear on wires from years of it moving on entry and exit. I did find that moving the wheel all the way in (towards the engine) and up would sometimes allow the car to start. But not always, and more recently I’ve found that just by turning the key to on, waiting 10 seconds, and then turning to start would allow the car to start. It’s puzzling, and seems like it could be the alarm system over riding it, or something similar because when my car does start, it does so with ease. My next plan is to replace the AC controller, I can’t recall exactly the name, but it’s a white plastic box that lives under the CD changer in the stereo. Hope one of us finds a solution!
 

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If it is smart key system could be fob failing
Does the red led status light on dash go off or stay lit.If it stays on your BCM is not seeing your transponder chip and the is stopping the car from starting.I had the same problem ended up being the antenna that is supposed to pick up your chip info and pass it along to the BCM.It is a device wrapped around your cars ignition switch.Hope this helps.
 

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I realize this is reviving an old thread; however, I just experienced this intermittent starting issue with my new-to-me 2003 FX45 (106k miles). My battery is good, starter spins quickly when it starts. It acted like a dead battery, but after retrieving cables to jump it off I tried it again and it started normally. Any helpful hints about what might be going on?
 

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I think this is a symptom that is hard to say for certain what is going on, but based on my experiences with this same problem in my 2004 FX45, I will try to help:

1) If your starter engages this is the first clue. I.e., you fix maybe that you need to change the Crank Position Sensor (CKP aka CPS) located on the bottom of your engine... above the passenger skid plate... and you find it where the transmission mates with the engine. This OEM part is made by Hitachi # CPS007. It is also the same part number as the lower Cam Sensor located in front of the engine. (This is not the same as the two cam sensors up top.) It's not hard to replace. (See #5 sensor in the diagram below.)

Note: One mechanic told me the crank position sensor will go out first since the crank shaft spins twice as fast as the cam shaft. I.e., don't worry about replacing the other sensors.
Organism Font Line Parallel Illustration


2) If your starter does not engage then you could have any number of possible things going on.

A) Sometimes you can turn your key off and then on again and the engine will start.

This problem has be traced to a "cold soldier joint" inside the Air Conditioning Control Box and is called an AC-Amplifier. Most people in cold climates have experienced this problem. And FYI, the AC-Amplifier is a box located under you radio. And the reason you starter will not engage (I think) is because cause the AC-Amplifier is interfering with the signal to the BCM that is monitoring your security system and your transmission position switch.

B) I had this same problem 1 year ago and I cleaned all the fuses in the box next the driver's left knee and that fixed my problem. So, I would recommend you do that. Just get a brass wire brush and take that oxidation off those fuses. And since it's not hard, you might as well clean all the fuses.

C) There is a fuse box where you battery is located too. And while I did not clean these fuses I plan to soon since this problem reappeared 1 year later.

Note: Two days ago, 11/13/22, my engine did not start and I moved the gear selector from park to neutral and the engine started. I then let it run for 5 minutes. Turned off the car and then tried restarting the engine... and NOTHING HAPPENED. Then, I used a lithium battery pack to start my car. Let the engine run for a while, Turned the engine off... AND THE ENGINE RESTARTED!!!

However, the no-start condition occurred just after I double-clicked on my key fob, which made all the windows drop half-way, just like they are supposed to. So maybe all that current... driving old window motors... caused the BCM to malfunction and/or trip a security warning condition that prevented my car to start. This is all speculation of course, but I think it is possible.

In any event, myself and other FX owners have found that if you give your car 10 seconds to 2 minutes before trying to restart your engine, again, then this can get you on your way.

So, I think we have a number of systems communicating to the BCM which controls relays to the starter. However, finding the solution is still not 100% clear to me.

D) If after you clean your fuses; and you still experience a no-start condition (and you did not drop your windows halfway using your fob like I did), then maybe that AC-Amplifier is your problem... especially if you are in cold weather. Also, I think this AC-amplifiers have several different part numbers based on the way your FX was ordered from the factory. And BTW, a cold (aka cracked) solder joint is easy to find with a pair of reading glasses, and can be fixed with a simple soldier iron. Or you can pay an electronics/stereo repair shop $50 to do a board level check and soldier reflow job that will be faster and cheaper then finding a replacement AC-amplifier.

E) These problems may point to a bad BCM too. However, there is one more possible fix I am exploring now...

F) What if all these problems are due to a weak ground to the BCM? ...And all we need to do is add a ground wire to a specific pin?

==> ...If anyone can give us instructions on which BCM pin we can add a ground wire to, please let us know how to do this?


I haven't looked in to this option, but I plan to do so at some point.
 

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I think this is a symptom that is hard to say for certain what is going on, but based on my experiences with this same problem in my 2004 FX45, I will try to help:

1) If your starter engages this is the first clue. I.e., you fix maybe that you need to change the Crank Position Sensor (CKP aka CPS) located on the bottom of your engine... above the passenger skid plate... and you find it where the transmission mates with the engine. This OEM part is made by Hitachi # CPS007. It is also the same part number as the lower Cam Sensor located in front of the engine. (This is not the same as the two cam sensors up top.) It's not hard to replace. (See #5 sensor in the diagram below.)

Note: One mechanic told me the crank position sensor will go out first since the crank shaft spins twice as fast as the cam shaft. I.e., don't worry about replacing the other sensors.
View attachment 20865

2) If your starter does not engage then you could have any number of possible things going on.

A) Sometimes you can turn your key off and then on again and the engine will start.

This problem has be traced to a "cold soldier joint" inside the Air Conditioning Control Box and is called an AC-Amplifier. Most people in cold climates have experienced this problem. And FYI, the AC-Amplifier is a box located under you radio. And the reason you starter will not engage (I think) is because cause the AC-Amplifier is interfering with the signal to the BCM that is monitoring your security system and your transmission position switch.

B) I had this same problem 1 year ago and I cleaned all the fuses in the box next the driver's left knee and that fixed my problem. So, I would recommend you do that. Just get a brass wire brush and take that oxidation off those fuses. And since it's not hard, you might as well clean all the fuses.

C) There is a fuse box where you battery is located too. And while I did not clean these fuses I plan to soon since this problem reappeared 1 year later.

Note: Two days ago, 11/13/22, my engine did not start and I moved the gear selector from park to neutral and the engine started. I then let it run for 5 minutes. Turned off the car and then tried restarting the engine... and NOTHING HAPPENED. Then, I used a lithium battery pack to start my car. Let the engine run for a while, Turned the engine off... AND THE ENGINE RESTARTED!!!

However, the no-start condition occurred just after I double-clicked on my key fob, which made all the windows drop half-way, just like they are supposed to. So maybe all that current... driving old window motors... caused the BCM to malfunction and/or trip a security warning condition that prevented my car to start. This is all speculation of course, but I think it is possible.

In any event, myself and other FX owners have found that if you give your car 10 seconds to 2 minutes before trying to restart your engine, again, then this can get you on your way.

So, I think we have a number of systems communicating to the BCM which controls relays to the starter. However, finding the solution is still not 100% clear to me.

D) If after you clean your fuses; and you still experience a no-start condition (and you did not drop your windows halfway using your fob like I did), then maybe that AC-Amplifier is your problem... especially if you are in cold weather. Also, I think this AC-amplifiers have several different part numbers based on the way your FX was ordered from the factory. And BTW, a cold (aka cracked) solder joint is easy to find with a pair of reading glasses, and can be fixed with a simple soldier iron. Or you can pay an electronics/stereo repair shop $50 to do a board level check and soldier reflow job that will be faster and cheaper then finding a replacement AC-amplifier.

E) These problems may point to a bad BCM too. However, there is one more possible fix I am exploring now...

F) What if all these problems are due to a weak ground to the BCM? ...And all we need to do is add a ground wire to a specific pin?

==> ...If anyone can give us instructions on which BCM pin we can add a ground wire to, please let us know how to do this?


I haven't looked in to this option, but I plan to do so at some point.
Thanks for your well-thought-out reply. You provided a lot of very useful information, thank you. Fortunately, this was a one-time occurrence for me at this point, but I strongly suspect it will happen again. Cleaning the fuses is quick and easy, I will do that right away.
 

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PGAWest: There are many of us living with this intermediate no-start problem that signals the Body Control Module (BCM) is not letting the starter engage and spin. And in this case cleaning the fuses next to the emergency brake would be a good first step. This is the fuse block to the BCM and AC-Amplifier is located in the side-panel next to the emergency brake.

==> I'm also thinking this is a good point to add a ground wire, but I have not explored this idea. Maybe the next time I have to diagnose a no-start problem I will do this.

ALTERNATIVELY, you said you were able to crank your engine, but it would not start. So, this is likely a different problem. And I think it is more likely you do have:

A) A weak Crank Position Sensor (CPS or CKP) (See #5 in the diagram above) and I would change it the next time you pay for an oil change. (And it is very easily replaced and I recommend you stay with the Hitachi brand for $45 you can pick up at Auto Zone and not O'reilly as they carry a different brand.)

B) Or the fuses co-located next to your battery may have film on them which is preventing the ECM and or BCM to function properly. ...Possibly. ...It could not hurt, but you may need to remove the battery to get to this fuse block. I have not performed this service myself, but I can tell you the fuses next to the emergency brake were oxidized and after I cleaned them that seemed to help me with my no-start and no starter engagement problem. (Suggesting the BCM was sensing ground problem or open circuit or short circuit.)

If you do this, please let us know how you made out and how easy it was to clean these fuses.

For those of us who are able to start our engine after 30 seconds to 2 minutes, I suspect this is being caused by an "open" PTC-R in the door lock device. A PTC-R works like an auto-reset fuse. They put this dime size wafer (semiconductor device) on the power wire that goes to each door lock device. And it is supposed to "open" the circuit if it gets too hot. And, over time, the added resistance and breakdown of the semiconductor material, this results in a "open-circuit" condition, but only for the period of time it takes the PTC-R to cool down. And for some this is 30 seconds and for others this is 2 minutes.

* I suspect that if the BCM cannot sense the circuit then it will not let your starter crank.

* If you turn your key and you hear the starter engage, but the engine will not start, then this points to a starter or starter solenoid problem. Just don't let the dealer or some other repair shop convince you to replace the starter if you have an intermittent no-start, no-starter engaging problem.
 

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Just adding: I think all FX owners should carry a lithium jump pack. Why? Because for whatever reason you can't start the car, I have found that every time I just need to jump my battery and that will get you on your way. Or you can plan to spend hours waiting for a tow if you engine will not start after letting it sit for a while. (3-10+ minutes on average, if this works at all???)

You also clean a number of key fuses with a wire brush. I recommend you disconnect the battery first and you may need to do this anyway to access the fuse block where the battery is located.

Attachment: pdf
 

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