47re OSS Circuit Info Needed

ARbowhunter7

ARbowhunter7

Opulence...I Has It.
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Sep 8, 2007
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1,370
OK, I've been working with Goerend to chase a 2nd gear start issue in a 96 47re and have it narrowed down to the OSS, which is the circuit that I need some info on. Dave and Bob have been exceedingly helpful, but my schedule at work doesn't generally afford me the luxury of accepting a phone call back from them during the day, so I'm hoping someone here can lend a hand.

Trans shifts perfectly (shift sequence, timing, gear selection, etc.) with OSS unplugged at the trans, but immediately reverts to 2nd gear start condition with OSS connected. I've already replaced OSS, so I'm looking at troubleshooting the OSS to PCM circuit in (dwindling) hopes that I won't have to replace the PCM. What resistance or voltage values does the PCM need to see from the OSS in order to facilitate proper shifting?

And before anyone advises me to "Just leave it unplugged if it works that way", I definitely would love to, but I need the speedometer.


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Is that the two wire sensor or the three wire? Two wire is looking for frequency. Three wire is looking for a pulse train.
 
Give up and come to the dark side.....

Something smart goes here
 
biggy238 said:
Give up and come to the dark side.....

Something smart goes here
Click to expand...



I actually called a month ago to join the club you speak of, fully intent on placing an order on the spot. Unfortunately, the person who answered the phone was the dumbest m*****f***er to ever utter a breath.
I asked to speak with someone familiar with the software and, within the meager confines of a scant 4 minute conversation, this gentleman managed to not only prove that he knew almost nothing about the product, but could also provide directly incorrect information about truck compatibility at the drop of a hat. His final sales pitch (the closer, if you will), was that the ordering process was, "...a waiting list-type situation.", and that he "didn't know when they would be making another run." Needless to say, I went another route.
That said, I still hold that shop in extremely high regard, as well as the representatives they have on this forum. The knowledge they have and share here is unsurpassed. I would rank them in the top 3 shops in the country, hands down.


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The back ordering is correct. They are built in production runs. As for the rest, I just laughed until I cried. Some people shouldn't be let near phones.

My 96 wouldn't shift without OSS. I found twice that the wires were still in the connector, but the insulation was gone from the wires. Any time they got wet, things got out of hand.

Something smart goes here
 
I haven't been able to find and wires that are damaged or otherwise faulty, so I'm afraid that the PCM is receiving the correct OSS signal values, but then is processing the information incorrectly. It'd be nice to know what information the PCM needs to see from the OSS, so I rule certain things out.


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I swear, this option looks better by the minute.

ecbfd69d790423938bda2c7333c791aa.jpg



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Wait a minute. Are we talking about the OSS (output shaft speed) or VSS (vehicle speed sensor)?



OSS is 2 wire, vss is 3. VSS drives the speedometer directly. VSS would be why you need a speedometer.





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Also, did you have the pcm flashed? early built 96 trucks need a gas flash file to be happy with lockup. I wonder if that might help.

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biggy238 said:
Wait a minute. Are we talking about the OSS (output shaft speed) or VSS (vehicle speed sensor)?



OSS is 2 wire, vss is 3. VSS drives the speedometer directly. VSS would be why you need a speedometer.





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Click to expand...



I appreciate the continued response and help, but unfortunately that's incorrect. The OSS is a three wire plug (grey on black, orange on red, solid orange) located at approx. 10:00 position at the rear of the transmission, as viewed from the rear of the truck, looking forward.
The two wire plug located at the top of the rear diff (VSS) is primarily for ABS, unless signal is lost (or out of range) from the sensor on the rear output shaft (OSS). In that case the speedometer is inoperable, but the PCM calls on that diff sensor (VSS) for speed info in order to dictate upshift/downshift points.
If you don't think the speedo gets signal from the OSS, just unplug it.




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ARbowhunter7 said:
I appreciate the continued response and help, but unfortunately that's incorrect. The OSS is a three wire plug (grey on black, orange on red, solid orange) located at approx. 10:00 position at the rear of the transmission, as viewed from the rear of the truck, looking forward.
The two wire plug located at the top of the rear diff (VSS) is primarily for ABS, unless signal is lost (or out of range) from the sensor on the rear output shaft (OSS). In that case the speedometer is inoperable, but the PCM calls on that diff sensor (VSS) for speed info in order to dictate upshift/downshift points.
If you don't think the speedo gets signal from the OSS, just unplug it.




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Click to expand...
You got me. Tail (turbine) Shaft Speed is the one I was thinking of, and the one I would look at closely. Two wires in the tail housing

I also found that I had to index my OSS in an "incorrect" position to make it read consistently, as if the collar is abnormally loose

Something smart goes here
 
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