Intermittent failure to start...

FearlessLeadr · 03-06-2013, 11:33 PM

OK, after pulling the clutch sensor switch, taking it apart, and putting it back together, the issue seems to be resolved. However, after looking at the internals, I don't know how the computer knew it was installed. There's no circuit components, just a simple disconnect. Hopefully this is actually the problem and not just the issue deciding to go away for a bit.

FearlessLeadr · 03-06-2013, 11:38 PM

Quote:

Originally Posted by SouthArk370Z

If a bad clutch interlock switch is the problem, you can temporarily disconnect the connector on the switch and jury-rig your own switch until the replacement comes in. Flip your temporary switch to the proper position, start car, flip switch back to "normal" position until next start.

If you know what a 4-20mA loop is, you should be able to handle it.

Use at your own risk, not responsible for accidents or damage, &c, &c, &c.

Good idea, but it appears to have cleared up after taking apart the clutch switch and putting it back together. I have purposefully changed nothing though, so unless some piece of plastic or something was holding the connection closed, I have no idea how it's become fixed.

SouthArk370Z · 03-06-2013, 11:47 PM

Quote:

Originally Posted by FearlessLeadr

OK, after pulling the clutch sensor switch, taking it apart, and putting it back together, the issue seems to be resolved. However, after looking at the internals, I don't know how the computer knew it was installed. There's no circuit components, just a simple disconnect. Hopefully this is actually the problem and not just the issue deciding to go away for a bit.

Glad to hear it's working again. Keep the spare handy. It sounds like you fixed the problem (not just an intermittent that went away for a while), but the switch is likely to fail again soon.

According to the 2009 FSM, the interlock switch is a simple SPST switch - the module is looking for volts present or not. Some controls in the car are "smart", eg, window switches and SLU, but not the clutch interlock switch. Edit: Ie, the module doesn't know the switch is there until it closes.

FearlessLeadr · 03-07-2013, 12:11 AM

Quote:

Originally Posted by SouthArk370Z

Glad to hear it's working again. Keep the spare handy. It sounds like you fixed the problem (not just an intermittent that went away for a while), but the switch is likely to fail again soon.

According to the 2009 FSM, the interlock switch is a simple SPST switch - the module is looking for volts present or not. Some controls in the car are "smart", eg, window switches and SLU, but not the clutch interlock switch. Edit: Ie, the module doesn't know the switch is there until it closes.

Then shouldn't that mean that I could disconnect the switch entirely? When I press the button, it breaks the circuit, so shouldn't it just think the clutch is pressed if I disconnect the switch? I also tried a wire bridge and it didn't work.

mults · 03-07-2013, 07:34 AM

Quote:

Originally Posted by FearlessLeadr

Then shouldn't that mean that I could disconnect the switch entirely? When I press the button, it breaks the circuit, so shouldn't it just think the clutch is pressed if I disconnect the switch? I also tried a wire bridge and it didn't work.

I think that the ECU needs to "see" the switch open and close when necessary. If the switch is bridged like you say to keep it closed permanently, then the ECU does not see the change in state. I know when I try to start my car, the dash icon lights up that says to depress the clutch (switch closed) and then the car starts. If the ECU does not see the switch close, then the car will not start. It is a programmed sequence that has to happen otherwise, nada.

SouthArk370Z · 03-07-2013, 08:03 AM

Quote:

Originally Posted by FearlessLeadr

Then shouldn't that mean that I could disconnect the switch entirely? When I press the button, it breaks the circuit, so shouldn't it just think the clutch is pressed if I disconnect the switch? I also tried a wire bridge and it didn't work.

Since the bridge didn't work, it would seem that mults is right and the car has to see a transition. I suspected as much (it's not uncommon for interlock circuits), which is why I suggested using a switch.

FearlessLeadr · 03-07-2013, 02:35 PM

Quote:

Originally Posted by SouthArk370Z

Since the bridge didn't work, it would seem that mults is right and the car has to see a transition. I suspected as much (it's not uncommon for interlock circuits), which is why I suggested using a switch.

So, that means if I hold down my clutch, then start the car, then turn it off and try to start it again without releasing the clutch, shouldn't it not work?

SouthArk370Z · 03-07-2013, 03:15 PM

Quote:

Originally Posted by FearlessLeadr

So, that means if I hold down my clutch, then start the car, then turn it off and try to start it again without releasing the clutch, shouldn't it not work?

Try it and see. I'm just going by the wiring diagrams and a lot of things disappear into the ECM/BCM/&c where only Nissan knows what happens. It appears that the car is looking for a transition, but it may be less (or more) complicated than that.

FearlessLeadr · 03-07-2013, 10:44 PM

Strange, well, it hasn't done anything like it, so that must have been the issue. I'll just have to last until the new part shows up. Thanks for the help and interest.

FuszNissan · 03-08-2013, 10:12 AM

http://www.the370z.com/nissan-370z-w...ring-lock.html

wheee! · 07-02-2013, 11:15 AM

sub'd.... I have the same issue....

juld0zer · 10-07-2013, 10:38 AM

the same switch is also used to trigger SRM.

did any of you guys experience any sloppy shifts/SRM not doing its thing as expected when your clutch switch prevented the car from starting intermittently?

and for those who experimented with temporary fixes, did you encounter any irregular SRM behaviour?

wheee! · 10-07-2013, 10:59 AM

Quote:

Originally Posted by wheee!

sub'd.... I have the same issue....

wow, forgot about this thread...

see here for solution:
Car won't start!...and it's not the Steering Lock...

Quote:

Originally Posted by juld0zer

the same switch is also used to trigger SRM.

did any of you guys experience any sloppy shifts/SRM not doing its thing as expected when your clutch switch prevented the car from starting intermittently?

and for those who experimented with temporary fixes, did you encounter any irregular SRM behaviour?

Never had any issue with SRM....

juld0zer · 10-09-2013, 06:58 PM

my SRM issue turned out to be the Input Speed Sensor on the gearbox. It had some blobs of fine metal particles stuck to it (it's a magnetic flux type device).

Cleaned it up and shifting has never felt so good

cheers for the reply though

wheee! · 10-10-2013, 02:15 PM

Hall effect sensors are notorious for failing after magnetic debris gathers on or near them....

Good find! Now swap out your tranny fluids to synthetic....

03-08-2013, 10:12 AM	#25 (permalink)
FuszNissan A True Z Fanatic Join Date: May 2009 Location: St. Louis Posts: 14,275 Drives: Pure Sex Rep Power: 542	http://www.the370z.com/nissan-370z-w...ring-lock.html __________________ Mods: Too Many to list! LouFuszNissan ZDAYZ 2012

07-02-2013, 11:15 AM	#26 (permalink)
wheee! A True Z Fanatic Join Date: Sep 2009 Location: Mod Capital of Canada Age: 58 Posts: 7,354 Drives: cars. lots of cars. Rep Power: 40182	sub'd.... I have the same issue.... __________________ H&R / Stillen / Berk / HKS / Swift / Michelin / UpRev / SPC / Amuse Rep / Seibon / Fringe XVO / TWM / more... My Journal

10-09-2013, 06:58 PM	#29 (permalink)
juld0zer Enthusiast Member Join Date: Nov 2012 Location: Sydney Posts: 428 Drives: 11 Nissan 370Z MB M6 Rep Power: 139	my SRM issue turned out to be the Input Speed Sensor on the gearbox. It had some blobs of fine metal particles stuck to it (it's a magnetic flux type device). Cleaned it up and shifting has never felt so good cheers for the reply though wheee! and SouthArk370Z like this.

10-10-2013, 02:15 PM	#30 (permalink)
wheee! A True Z Fanatic Join Date: Sep 2009 Location: Mod Capital of Canada Age: 58 Posts: 7,354 Drives: cars. lots of cars. Rep Power: 40182	Hall effect sensors are notorious for failing after magnetic debris gathers on or near them.... Good find! Now swap out your tranny fluids to synthetic.... __________________ H&R / Stillen / Berk / HKS / Swift / Michelin / UpRev / SPC / Amuse Rep / Seibon / Fringe XVO / TWM / more... My Journal

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03-06-2013, 11:33 PM	#16 (permalink)
FearlessLeadr Base Member Join Date: Mar 2013 Location: Hawaii Posts: 10 Drives: 09 370z Rep Power: 12	OK, after pulling the clutch sensor switch, taking it apart, and putting it back together, the issue seems to be resolved. However, after looking at the internals, I don't know how the computer knew it was installed. There's no circuit components, just a simple disconnect. Hopefully this is actually the problem and not just the issue deciding to go away for a bit.

03-07-2013, 10:44 PM	#24 (permalink)
FearlessLeadr Base Member Join Date: Mar 2013 Location: Hawaii Posts: 10 Drives: 09 370z Rep Power: 12	Strange, well, it hasn't done anything like it, so that must have been the issue. I'll just have to last until the new part shows up. Thanks for the help and interest.

10-07-2013, 10:38 AM	#27 (permalink)
juld0zer Enthusiast Member Join Date: Nov 2012 Location: Sydney Posts: 428 Drives: 11 Nissan 370Z MB M6 Rep Power: 139	the same switch is also used to trigger SRM. did any of you guys experience any sloppy shifts/SRM not doing its thing as expected when your clutch switch prevented the car from starting intermittently? and for those who experimented with temporary fixes, did you encounter any irregular SRM behaviour?