Help! Car ins't starting.
 

Hi all,

I've done an extensive amount of research the last two days but can't seem to figure out what the problem is. Not sure if anyone have experienced this.

Details:
2008 G35x Sedan with 72,xxx miles
Car was last used and an oil change was done on Sunday, 6/23. Tried to start the car on Wednesday, 6/25, nothing.

The car does not start, however, all headlights and interior lights turn on normally, as well as the radio, when the Start button is pressed. The fans will also turn on within 5-10 seconds after the boot screen.

Here's what's been done so far:

• IPDM failed last year and it was swapped out in June 2018 with one from another G35
• Battery failed last year and it was replaced in November 2018 with one from Infiniti
• Tried to jump the car via a booster battery and direct wire with a car - not successful
• Disconnected and reconnected the battery - still not successful
• Checked all fuses - all passed
• Checked battery tray area for water build up from rain - area is dry

I suspected that it was the starter but couldn't be sure. We finally had the car towed to a local shop.
What's been done by the shop:

• Checked the battery, alternator, and starter - all passed
• Checked for codes - none

The mechanics are also stumped on what may be causing the car to not start.
Has anyone else experienced this or have any other ideas?

Thanks in advance.

BCM/security system issues?

Thanks G2B35AGN.

I'm unsure if the BCM is having issues or not. I'll check with the guys at the shop tomorrow to see if they found anything that may trace to it.
The security system doesn't seem to be a problem since the iKey still works, locking and unlocking, even after disconnecting/reconnecting the battery. I could be wrong though.

Ok, lets start at the beginning since you're missing major details.

1. Does the engine CRANK when you press the start button?

2. Have you hooked it to an OBD2 scanner to check for codes?

3. Have you tried the iKey PHYSICAL key hidden inside the fob if it won't crank?

Hi cleric670,
To provide more details from your questions-

1. Does the engine CRANK when you press the start button?
No, it does not. It doesn't make any clicks or even attempt to turn over.
The screen does come on normally as you would have the car at the ACC position though. All the lights on the gauge cluster light up and not dim.

2. Have you hooked it to an OBD2 scanner to check for codes?
After the car was towed to the shop, they hooked it up to the ODB2 reader and no codes were thrown.

3. Have you tried the iKey PHYSICAL key hidden inside the fob if it won't crank?
I've tried sticking the whole key fob into the key port by the driver's left knee; still not able to start.
I'm not aware of the physical key being used to start the V36, but please enlighten me if there is such a method. I've never heard of this for a 2008 or a 2010.

Should pull out of the fob, the part that the keyring attaches is the BACK of the physical key. However it might be used just to unlock the physical lock on the door and might not be related to start function.

The next step of troubleshooting is to get the car up in the air and see if there is voltage present at the starter solenoid harness when you turn the key to START. I suspect you have a bad starter.

Right, the physical key is only used to lock/unlock the door when the button on the door isn't functioning, the glove box, and the rear center armrest access to the trunk.

My initial guess and even the tow truck driver's thought is that the starter might be shot too.
The guys at the shop did lift the car and checked all the main electrical components, battery, starter, and alternator. Voltage appears to be good for all the components but the car won't start.

G2B35AGN brought up the BCM of the car.
At this point, I'm not sure if the guys at the shop were able to find anything that traces back to the BCM that will cause the car to not start.

You need to verify that they did indeed check for voltage at the starter solenoid when the start button is pressed. If it HAS voltage on the solenoid circuit when trying to start and it HAS voltage on the primary cable (the one going straight to the battery) but it still won't turn the starter motor then it's definitely a failed starter. Pull and bench test the starter for operation.

If it does NOT have voltage at the starter solenoid circuit but it DOES have voltage on the primary cable then there's something going on that's preventing the vehicle from closing the starter relay, there are various components to troubleshoot.

Make sure they're testing voltage with a digital multimeter and doing it WHILE SOMEONE IS TRYING TO START THE MOTOR. A bad battery will cause an issue where the voltage will drop from 12v down to like 5 or 7v when you try to engage the starter, there won't even be a clicking sound most of the time when it's that low.

The starting circuit has various components, from:

-NATS/IVIS interlock (you would have the security indicator flash when trying to start)

-bad antenna not registering the iKey (roll the window down, place keys on the seat, manually lock door, close door. It should unlock itself because it knows the keys are still in the vehicle)

-iKey itself might be bad (failing transponder which controls start function, nothing to do with unlocking the vehicle)

-the BCM may have had a heart attack and forgot the transponder pairing for that iKey

-start relay in the IPDM may have failed

-ECM sends the start function to the IPDM and it may have failed

Most of these issues are diagnosed quickly by Nissan with the Consult-III diagnostic tool, they can read the state of the BCM and ECM and be able to tell if it's recognizing the key, sending the start request, etc. Call Nissan and ask their diagnostic rate and how long they think it would take to troubleshoot. They're usually $125/hr and can probably find the problem with a 1 hour diagnostic.

Check the neutral switch if it's automatic or the clutch switch if it's manual. These switches prevent power to the solenoid of the starter, unless the transmission is in "Park" for automatics, or the clutch is fully depressed for manuals. If automatic, also check break pedal switch.

Thank you, cleric670!

I'll check with the guys at the shop today and bring up the points that you've mentioned.
The good thing is Nissan is about a 1/2 mile tow, if I need to tow it there, from the current shop but for them to perform any work is going to cost arms and kidneys.

Thank you, Mr.GEE!

I'll bring this up and have them check this as well.

Just wanted to update everyone on the findings.
I've provided all of your suggestions while they were troubleshooting the issue. It is found that the IPDM has failed...again.

They were able to get the car to start when they did a bypass.

When did you last have the IPDM replaced and was it a new or used one?