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Neutral Safety Switch

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51K views 20 replies 10 participants last post by  Hydro  
#1 ·
Where is the neutral safety switch on a 2007 f350? I was told by someone that it was on the drivers side of the transmission but i cant find it and I cant find anything that looks like it. All i see is a plastic piece that what looks like the linkage goes to but i dont know if thats what im suppose to be looking for
 
#2 · (Edited)
You had suggestions on your other thread. Did they not work? It would be helpful to keep that thread updated.

Regarding your specific question -

Transmission Range (TR-P) Sensor Assembly
The transmission range (TR-P) sensor assembly is an internally mounted sensor that includes the detent spring, rooster comb and bracket, located next to the solenoid body. The components of the TR-P sensor are factory adjusted to each other and the sensor must be installed as a calibrated assembly. The TR-P sensor contains electronic circuitry that provides the PCM a fixed frequency at a duty cycle for each of the various positions of the manual lever (PARK, REVERSE, NEUTRAL, DRIVE, M3, M2 and M1) to the PCM. The PCM uses the TR-P sensor signal for engine functions (start, reverse lamps) and for line pressure control, shift scheduling and TCC operation.

IMO it does not fail very often. Personally I don't recommend the average owner replacing it on their own.
 

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#3 ·
You had suggestions on your other thread. Did they not work? It would be helpful to keep that thread updated.

Regarding your specific question -

Transmission Range (TR-P) Sensor Assembly
The transmission range (TR-P) sensor assembly is an internally mounted sensor that includes the detent spring, rooster comb and bracket, located next to the solenoid body. The components of the TR-P sensor are factory adjusted to each other and the sensor must be installed as a calibrated assembly. The TR-P sensor contains electronic circuitry that provides the PCM a fixed frequency at a duty cycle for each of the various positions of the manual lever (PARK, REVERSE, NEUTRAL, DRIVE, M3, M2 and M1) to the PCM. The PCM uses the TR-P sensor signal for engine functions (start, reverse lamps) and for line pressure control, shift scheduling and TCC operation.

IMO it does not fail very often.


The only thing on that thread that i havent tried yet is the part about the remote start and all that. But I still havent had any luck with getting it started and a guy that specializes in 6.0's told me to look at that switch. If i cant figure it out, im going to take it to him.
 
#5 · (Edited)
Other things (not very common, but easy to check) that can cause a no-crank are shorted out v-reference sensors. You can try cranking w/ the EGR valve, MAF sensor, GPCM, ICP sensor , IPR valve, EBP sensor all disconnected (to name the major players).

Another test is to see if fuse F2.22 circuitry is a giving you a problem (visually check the fuse first) is to unplug and crank w/ the middle PCM plug disconnected. This is PCM plug C13881c (it feeds about half of the engine sensors, including the fan clutch, EGR, GPCM, and the EBP sensor). F2.22 circuit also provides PCM power ... and problems this circuit will cause a loss of cranking. MAF, EGR, IPR, GPCM, and Fan Clutch are involved in that circuit via (these are all in the C1381c "middle" connector). C13381a contains the MAF and Fuel Bowl circuits, but it also contains the starter relay circuit and network communication, so it wouldn't crank w/ that disconnected. C1381b (end plug towards the front) is primarily the transmission controls.

As stated above, I wouldn't advise the average truck owner to mess w/ the range sensor.

Edit - here are several good reads:
https://www.powerstroke.org/forum/6-0-motor-problems/75011-04-6-0-wont-crank.html

https://www.powerstroke.org/forum/6-0l-problems-forum/206902-no-crank-no-start.html

Best of luck.
 
#18 ·
Other things (not very common, but easy to check) that can cause a no-crank are shorted out v-reference sensors. You can try cranking w/ the EGR valve, MAF sensor, GPCM, ICP sensor , IPR valve, EBP sensor all disconnected (to name the major players).

Another test is to see if fuse F2.22 circuitry is a giving you a problem (visually check the fuse first) is to unplug and crank w/ the middle PCM plug disconnected. This is PCM plug C13881c (it feeds about half of the engine sensors, including the fan clutch, EGR, GPCM, and the EBP sensor). F2.22 circuit also provides PCM power ... and problems this circuit will cause a loss of cranking. MAF, EGR, IPR, GPCM, and Fan Clutch are involved in that circuit via (these are all in the C1381c "middle" connector). C13381a contains the MAF and Fuel Bowl circuits, but it also contains the starter relay circuit and network communication, so it wouldn't crank w/ that disconnected. C1381b (end plug towards the front) is primarily the transmission controls.

As stated above, I wouldn't advise the average truck owner to mess w/ the range sensor.

Edit - here are several good reads:
04 6.0 won't crank...

no crank no start

Best of luck.
That was some great advice, I found a bad Fan Clutch that was causing the no Start problem.
 
#6 ·
Does it turn over at all or just nothing when you try to crank? I had a short in a wire from my PCM to my ignition that caused my truck to not turn over when it was humid out, because the moisture was completing the ground. Then, I hit a puddle and it finished the ground and just shut my truck down one day. I didn't put two and two together, until that day, I only thought it was intermittent.
@bismic really knows his stuff, though.
Sent from my SM-N950U using Tapatalk
 
#7 · (Edited)
Thanks for the kind words mbsfield18. Electrical issues can be so "individualized and unique" that it is sometimes hard to be a lot of help over the internet. It is especially hard when the communication is limited.

Here is the OP's original no-crank thread for a reference:
https://www.powerstroke.org/forum/general-6-0l-discussion/1373027-no-start.html

One thing (not saying that this is the case in this thread) I have seen multiple times is that some people "blow off" advice on checking out the fan clutch or its wiring as a cause for a no-crank (those folks have a REAL hard time understanding how a v-reference sensor could cause a no-crank). I am guessing it is because they "know someone" that says it is poor advice.

Hopefully he doesn't spend much time looking for that external Neutral Safety Switch.
 
#10 ·
Thanks for the kind words mbsfield18. Electrical issues can be so "individualized and unique" that it is sometimes hard to be a lot of help over the internet. It is especially hard when the communication is limited.

Here is the OP's original no-crank thread for a reference:
https://www.powerstroke.org/forum/general-6-0l-discussion/1373027-no-start.html

One thing I have seen multiple times is that some people "blow off" advice on checking out the fan clutch or its wiring as a cause for a no-crank (those same people have a REAL hard time understanding how a v-reference sensor could cause a no-crank). I am guessing it is because they "know someone" that says it is poor advice.

Hopefully he doesn't spend much time looking for that external Neutral Safety Switch.
I’ve only looked for it once
 
#14 · (Edited)
There isn't a neutral safety switch. It is a transmission range sensor, which is more complicated than a simple switch.

A short in the fan clutch wiring can cause issues with cranking, as the transmission range sensor output to the PCM can, because they are in the same wiring path for PCM power (via fuse F2.22 power supply) and same "logic path" for starter activation. F2.22 power is fed from the PCM Power Relay in the CJB ... which feeds power to the fan clutch and is routed in the fan clutch wire bundle from PCM connector C1381c middle plug....and it provides power to PCM plug C1381b (end plug) which is transmission controls and the reverse lamp relay control.

Simply unplugging the fan clutch will not cause any problems as long as you don't run it that way (ie just start it). As I posted in your other thread, unplugging the sensor and trying to start is one way that you check for an issue w/ the fan clutch. Of course you could still have issues in the wiring harness itself that could cause problems even if the clutch is ok .....
 
#15 ·
Wouldn't the sun load sensor on the upper dash blink if there was a PATS system in use?

About the vRef(5 volts) testing with a meter for the 5 volt presence in any of those three wire sensor connectors would show if it was shorted or not

There is also a 12 volt vPowr line that needs tested -- this one operates some of the relays
 
owns 2006 Ford F250 Lariat FX4
#17 ·
I have an ‘03 F350 6.0, with the 5 spd auto. It wouldn’t start one day after I had been meaning to adjust the gear selector on the column. I just kept lifting up on the selector to start it. After it wouldn’t start, I adjusted the selector and it started. But be careful to not over adjust because the very small cable can break...I know because I’ve seen me do it (to steal a line from Ron White).
Just a thought in case nothing else is working
Very Respectfully,
Larry
 
#21 ·
I have a difficult time remembering to go back and check on threads , to see if they are resolved

glad you brought this up
 
owns 2006 Ford F250 Lariat FX4
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