4L80E Park Neutral Safety Switch - leftover wires?
03-03-2010, 09:11 PM
#1
4L80E Park Neutral Safety Switch - leftover wires? The wiring harness is from a 2006 Sierra 2500HD with a 4L80E and 4WD - I got rid of all the 4WD stuff, I think...
Running from the Park Neutral Safety switch (PNP) to where the fuse block used to be:
#1 - Dark Green - runs from PNP switch pin #1 to where the fuse block used to be
#9 - Light Green - runs from PNP switch pin #9 to where the fuse block used to be
#12 - Pink - labeled "PNP Sw Ign" runs from PNP switch pin #12 to where the fuse block used to be
What the heck are these wires for? Are they some extra 4WD wires? I can't seem to find them in any of the schematics...
The #12 looks like a power source to the switch, but for what?! Anybody know what these are for, and if I need them?
Running from the Park Neutral Safety switch (PNP) to where the fuse block used to be:
#1 - Dark Green - runs from PNP switch pin #1 to where the fuse block used to be
#9 - Light Green - runs from PNP switch pin #9 to where the fuse block used to be
#12 - Pink - labeled "PNP Sw Ign" runs from PNP switch pin #12 to where the fuse block used to be
What the heck are these wires for? Are they some extra 4WD wires? I can't seem to find them in any of the schematics...
The #12 looks like a power source to the switch, but for what?! Anybody know what these are for, and if I need them?
03-05-2010, 04:41 PM
#3
Dude,
your hands looks soft and clean. Go work on yer car! LOL
your hands looks soft and clean. Go work on yer car! LOL
03-05-2010, 05:23 PM
#5
It's so funny that you say that! I looked at the picture and couldn't believe it was my hand! I started wearing rubber gloves at work about a month ago and my hands don't get dirty anymore... just dry.
I thought about re-taking the pic with my left hand, because from time to time the gloves have to come off and that's the one that does the work.
I thought about re-taking the pic with my left hand, because from time to time the gloves have to come off and that's the one that does the work.
03-05-2010, 05:26 PM
#6
I think if your park/neutral safety switch isn't reading park or neutral, the PCM won't let you start the car. Also, I want the PCM to raise idle when the A/C is on and the car is in park.
Those wires I am showing used to run to the fuse block, and I don't know what to do with them.
Those wires I am showing used to run to the fuse block, and I don't know what to do with them.
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03-05-2010, 06:23 PM
#8
I don't have any tuning software, so I can't edit the PCM. The harness is from a 2006 Sierra 2500HD 4L80E and 4WD. I went through all of the schematics, and the wires aren't in there. The schematics I am using are from a 2005. EVERY wire has been the same, but I cannot find these 3.
I really want to figure out what they're for so I can make the decision on whether to hook them up or remove them from the harness.
I really want to figure out what they're for so I can make the decision on whether to hook them up or remove them from the harness.
03-05-2010, 06:47 PM
#10
Okay, so the ones that go to the PCM... would that be the ones like:
PRND P SIG
PRND A SIG
PRND B SIG
PRND C SIG
I have all of those hooked up.
Also, I went through the Starting schematic one more time for the Sierra... and it looks like the pink wire runs from the ignition switch and feeds the PNP switch B+ and the dark green wire goes from the PNP switch directly to the starter relay. The PCM doesn't look like it's involved at all. (It looks like an independent stand-alone safety circuit)
Further, I am using a fuse box from a 2008 Impala 3.5L (I know, what a cluster f%*k, right?) and I have everything setup to use the starter solenoid/relay in the Impala fuse box.
So based on all that, is there anything that the PCM needs to see before it will allow the car to start? Is that what the "PRND P SIG" thing is for?
Thanks, I know this is not fun stuff but I need to scholg through it before I start soldering.
-Dave
PRND P SIG
PRND A SIG
PRND B SIG
PRND C SIG
I have all of those hooked up.
Also, I went through the Starting schematic one more time for the Sierra... and it looks like the pink wire runs from the ignition switch and feeds the PNP switch B+ and the dark green wire goes from the PNP switch directly to the starter relay. The PCM doesn't look like it's involved at all. (It looks like an independent stand-alone safety circuit)
Further, I am using a fuse box from a 2008 Impala 3.5L (I know, what a cluster f%*k, right?) and I have everything setup to use the starter solenoid/relay in the Impala fuse box.
So based on all that, is there anything that the PCM needs to see before it will allow the car to start? Is that what the "PRND P SIG" thing is for?
Thanks, I know this is not fun stuff but I need to scholg through it before I start soldering.
-Dave
03-05-2010, 07:02 PM
#11
Further, I am using a fuse box from a 2008 Impala 3.5L (I know, what a cluster f%*k, right?) and I have everything setup to use the starter solenoid/relay in the Impala fuse box.
So based on all that, is there anything that the PCM needs to see before it will allow the car to start? Is that what the "PRND P SIG" thing is for?
03-05-2010, 07:05 PM
#13
Also, like was asked before, why don't you just use the neutral safety switch that the car came with? There's nothing in the PCM that will prevent the engine from starting if you don't use the starter relay in the fuse box. It would simplify things.
03-05-2010, 07:32 PM
#14
Now wait a minute - I am trying to use the fuse box starter relay from an Impala, not the Sierra. I have all the Impala schematics, and it does not look like the Impala has any sort of neutral safety switch. Once you give that Impala fuse box starter relay some power, it cranks your engine. In contrast, the Sierra has a PNP switch that you have to go through on the way to the starter relay.
The true question is "what does the PCM (and only the PCM) need to energize the starter relay wire?" and turn on the fuel, ignition, etc so the car will start.
The true question is "what does the PCM (and only the PCM) need to energize the starter relay wire?" and turn on the fuel, ignition, etc so the car will start.
03-05-2010, 07:36 PM
#15
Awesome, I think that answers my question!
And I missed it before, but that's a good idea. I think the Jag has some sort of neutral safety switch built into the shifter... I could probably use that. I bet it's already wired in line with the ignition switch too.
And I missed it before, but that's a good idea. I think the Jag has some sort of neutral safety switch built into the shifter... I could probably use that. I bet it's already wired in line with the ignition switch too.
