2011 QX56 with start button no start issue

[ukrkoz]

I figure, I must be doing something wrong, but I'll ask anyway.

No, this is not the same issue as in this post:

https://www.clubarmada.com/threads/2010 ... ing.92246/



I had my QX for about year and a half and never had no start situation

As of the last few weeks, when I press brake pedal and tap Start button, it'll simply go into ACC mode and will not start.

Then I have to cycle all the way to Off, restart, and it starts fine.

Battery checked, it's full and healthy

No error lights

It just jumps into ACC mode and then no start.

I tried to press Start button harder or longer, it's crap shot. Either starts or goes into ACC.

So far, best result is pressing brake pedal real hard and tapping Start button. Then I'm good. Brake pedal position sensor mulfunction?

Any ideas? It just started, maybe 10 days ago. On-off situation, no pattern.

Thank you

[VStar650CL]

On an I-Key vehicle, the culprit is most likely the brake pedal switch. See if you have brake lights when it refuses to start. If the lights are out, the pedal switch is bad. Very common problem.

[ukrkoz]

That's what it sounds like. I already ordered both switches. Will be PITA to do with me being 6'2'' and very broad shouldered. I'll manage.

[VStar650CL]

It's actually super simple and takes no tools. Both switches are twist-lock, just twist counterclockwise to remove, then insert the new ones till the plungers bottom and twist clockwise. The only caveat is to make sure you don't accidentally depress the pedal with your elbow or shoulder during installation, then the new switch will be at the wrong depth and will lock your brakes.

[ukrkoz]

Yes, I saw videos. It's just ME fitting there and being able to move.

[VStar650CL]

I'm 6'0" and I have no problem with the Armada switches. In fact, I can pretty much get one out blind.

Now Versas and Sentras, that's another story....

[ukrkoz]

OK, back to issue.
I had both brake switches replaced. Yes, was not that hard, just quite awkward.
Did this about a month ago and no start issue went away.
Then, it returned and sort of getting worse, took me about 5-6 attempts this morning to start the vehicle.
This is what happens:
I press brake pedal>tap Start button> dash illuminates> steering wheel goes down> sign illuminates "press brake/tap Start> tap Start>click>tap start>click>tap start>click.
Shut down system, try again, it may go to dash On again or, may start.
What are the clicks about then? Bad starter relay?
Also, before all this happened, about 6 months back, I started having odd noise before starter will crank. It sort of sounded like "whooooooooooop" and then starter will engage. That noise is right after I tap the Start button and is on and off, not every time.
I'm getting suspicious, it's actually starter acting up, and that noise is Bendix not engaging flywheel all the way. Same time, it does not sound like any bad starter noise I ever heard before. No consecutive clicks, no idle spins, no staccato of Bendix solenoid clicking.
As you know, that starter is quite buried..
Ideas? Hate to be caught for good somewhere.

[VStar650CL]

Clickety-clacks are almost always a bad battery, low battery, or bad battery connection. Bad starters don't do that, they either "clack" once but don't spin (bad brushes) or make no noise at all (bad solenoid/contactor). Get AutoZone to check your battery, and if it tests good, put a voltmeter on it when it misbehaves. If it's below about 12.2V then monitor your charging voltage, your "smart charging" may be getting stupid. There's an easy fix for that. If charging and voltage both check okay, start looking for a bum connection.

[VStar650CL]

PS -- A low battery can also cause a Bendix to not engage fully, so don't condemn the starter based on that. If it still does that after fixing the clickety-clacks, then condemn it.

[ukrkoz]

Battery full charge. I also had it scoped by battery tester few weeks ago, shows as top condition.

[ukrkoz]

I think, I figured, it's not starter.
Reason being simple. I have remote start and it will crank/start off remote 10 out of 10. So it's not starter OR starter relay, apparently.
Ok, so new brake switches - just checked, both sit in place solid - not starter, WDH is it then?

[VStar650CL]

When you start remote, the BCM doesn't switch on anything it doesn't need. So a marginal battery or crappy connection will affect it a lot less than when you climb into the vehicle and everything lights up.

Clickety-clacks are only caused by two things, low voltage, or resistance which results in low voltage. So there aren't a whole lot of possibilities. Since the battery is good then check the charging system, and if that's good then look for bad connections.

[ukrkoz]

OK:
1. battery is good. Was checked by battery tester not so long ago. Battery is only several years old.
2. There are no "clickety clucks". There is ONE click, sounding like relay click, during press Start button. ONE.
3. Gauge always shows charging current at over 14V and, I also had it checked with voltmeter, was 14.8
4. I have battery tender connected on top of that, so battery does not run low.
We can rather safely eliminate battery as cause.

[VStar650CL]

Ah, one hard click is different. You got me a little confused with "Start> tap Start>click>tap start>click>tap start>click" in your post. One click usually indicates a bad starter, but with the starter working 100% on remote, that doesn't exactly jive. See PCS-17 here for your IPDM layout...
https://www.nicoclub.com/service-manual ... %2FPCS.pdf
...and put a test light on pin 3 Red when it misbehaves. If you get a nice, bright lamp then the IPDM is doing its job and the problem is in the starter. If you get a dim lamp then the problem is in the IPDM, one of the relays is going bad. If you get no light then the clicking you're hearing isn't a starter relay, and if it isn't the brake switch causing the issue then the problem gets complicated. We'll cross that bridge if you come to it.

[ukrkoz]

Yeah... dumb electric am I.... I'm mechanical guy.... Well, I have backup plan for now, should save me from getting stranded. Though I do have a good electrician... Just question of finding time to get car to him...

[ukrkoz]

I ended replacing starter.
Reason being, it literally got me caught last weekend, fortunately, in my property, with about 6-8 non starts in a row. Same, beside hearing the usual relay click, I hear faint whirr, typical of bendix not engaging properly. Faint, yet. So I said - yep, starter it is.
Job is not bad, except the pass side rear intake bolt and infamously over torqued starter bolts. And, not being able to really get any meaningful lever on them because of the thick harness overhang. Swivel wrench with extension is a MUST.
Starter was original Nissan one. The only things I could see wrong with it were peeling off paint, like as if it was overheating and BADLY corroded negative, with signs of overheating on it. Pretty sure, that rust greatly increased connection resistance.
Took me about 3 hrs, with 30 min trip to parts store as driver side PCV turned out to be broken in a half. Top section of it came out of the lower base. Biggest time taker was loosening pass side harness brackets and heater hoses bracket to gain some access to that bolt plus, getting that bolt back in. That was a b**** job, as you have to lay down on the engine to get to it, even with my 6'2'' and on step stool.