Push button start fails sometimes

[Dave Carney]

The dealer installed the new BCM, programmed it, and cold started the car this morning as a test. They said it started fine. I picked it up this evening. Is it fixed? I don't know, it won't be cold enough for me to test it again for a while. It was cold though when they tested it.

But, check this out. On the service order receipt, they reference code B1440 (as the cause behind my SVS on the DIC when it no-cranked) and they call this code "Fog Lamp Open" circuit. But according to my Helms and everything else I can find, this DTC is actually a Power Mode Master Input Circuits Mismatch. According to the Helms it's basically a communications mismatch between the BCM and the RCDLR. They list a procedure for testing the wires in the harness at the ignition switch ! (for specified resistance, voltage) and if the wires test ok, they say to replace the ignition switch. This makes a lot of sense. Simple. And cheap if it's only the switch, $25. I could do this test myself and I will if it no cranks again.

 

[compyelc4]

By any chance is there another remote start Fob on you or in the vicinity? The reason I ask is I have had this happen a couple of times with my pushbutton start '07 Nissan Altima. Now I've noticed that whenever this no-ignition condition occurs I also have my '95 Vette Fob on me. Once I remove my Vette fob I'm back in business. I've heard this can also occur with some cell phones as well. Make sure your cell phone is not on the same side of your clothing as the pocket containing your Fob.

 

[Dave Carney]

By any chance is there another remote start Fob on you or in the vicinity? The reason I ask is I have had this happen a couple of times with my pushbutton start '07 Nissan Altima. Now I've noticed that whenever this no-ignition condition occurs I also have my '95 Vette Fob on me. Once I remove my Vette fob I'm back in business. I've heard this can also occur with some cell phones as well. Make sure your cell phone is not on the same side of your clothing as the pocket containing your Fob.

No, no other fobs. Did the cell phone wax on wax off... dealer reproduced the problem when I wasn't even there.

 

[NORTY]

No, no other fobs. Did the cell phone wax on wax off... dealer reproduced the problem when I wasn't even there.

Any other RF products in the car? Pagers, garage door openers (especially the hi-tech ones that search for "billions and billions of codes"), radar/lidar detectors, IPOD? All/some or none of these could have an effect.

Or, it could just be a ground somewhere, but it could be anywhere (like a headlamp.)

 

[Dave Carney]

Problem presented with and without radar detector. The garage door opener remote is a fixed code unit from 1995. Don't own an IPOD.

 

[c4c5specialist]

B1440 is a power mode mismatch.
This would correlate with a BCM being an issue.
This is because the BCM is your gateway to the rest of the vehicle.
But, its more involved than just a switch, especially when the switch only TELLS the BCM to turn on, and the BCM does the rest.
From there, keep us posted, c4c5

 

[Dave Carney]

For sure it's more involved than the switch, I just did not want regurgitate 2 pages of helms info. There are 4 possiblities according to the helms.

1) A short/ground/resistance problem in one of the ignition switch wires
2) Bad BCM
3) Bad RCDLR
4) Bad Ignition switch

The BCM was just replaced. The checking of the wires and replacement of the switch I can do, should the problem resurface. After that, it's just the RCDLR