Transmission only drives in first and second gear

Tiny
LINDA COVINGTON
  • MEMBER
  • 1996 ISUZU TROOPER
  • V6
  • 4WD
  • AUTOMATIC
  • 230,000 MILES
My vehicle has no pressure line for my three or more gears. If I start out in second gear and dog it up to 4000 rpm's and hold it all of a sudden my transmission light will come on but then my truck drives somewhat like normal in second gear. What could be the problem? I am literally burning through transmission fluid driving like this. Now my check engine light has come on showing P1391. Which I believe is my G Sensor. I have been driving like this for some time now and the check engine light is new. Can anyone tell me why my transmission. Is doing this? Could it be my VSS sensor? Also, I have a power and winter drive push button for the transmission deliver-ability. If that is important to know.
Tuesday, August 29th, 2017 AT 12:00 AM

6 Replies

Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 49,912 POSTS
It does sound like a VSS that is going out.

Here are some diagrams (below) to show you where the sensor is:

Please let us know what happens.

Cheers, Ken
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Wednesday, August 30th, 2017 AT 11:55 AM
Tiny
LINDA COVINGTON
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Thank you for responding. I will definitely try that. One more question, will I need to change out my speedometer when I change out the VSS?
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Wednesday, August 30th, 2017 AT 3:15 PM
Tiny
LINDA COVINGTON
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  • 14 POSTS
Two more questions. Lol. Is there a tool I can use to pull that sensor without having to drop the transmission?
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Wednesday, August 30th, 2017 AT 3:17 PM
Tiny
KEN L
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Hi,

You will not need to replace the speedometer when replacing the VSS, to replace the sensor you should be able just to remove the rear cross member and lower the unit with a jack to get top the sensor without removing the transmission.

Please let us know.

Cheers, Ken
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Wednesday, August 30th, 2017 AT 4:42 PM
Tiny
LINDA COVINGTON
  • MEMBER
  • 14 POSTS
Hello Ken
I hope things are going well with you. I do apologize for the delay in response. I had some other life matters that came up. I am still in the same predicament when its comes the trooper. I changed out the VSS, Crankshaft Position Sensor, Neutral Safety Switch, and the Solenoid. When I pulled the VSS I can plainly see that the teeth on the gear have begun to CHIP away literally. I did not change out the speed sensors per hub. Could it be the Winter Mode Switch by chance? Or the other sensors? Even if I decide to just get a rebuilt transmission I honestly would like to know what the issue is? Again, thank you so much for your time and knowledge. Hope to hear from yoy soon!
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Sunday, September 17th, 2017 AT 5:16 PM
Tiny
KEN L
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  • 49,912 POSTS
Yep life can cause delays in car repair matters :) it does sound like the transmission is going out and needs to be rebuilt. Has it ever been rebuilt?

Please let us know

Cheers, Ken
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Monday, September 18th, 2017 AT 11:15 AM

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