Limp Mode
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03-31-2010, 12:08 PM
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Limp Mode
So anybody know why a tranny will go in limp mode? If i start the truck up and put it into gear right away it stays in first gear. If i turn the truck on and wait till the engine light go's on then the tranny it starts off in what feel like 2/3 gear. Very sluggish when i start off then after that it shifts just fine. I also get a nasty vibration when im on the highway. not sure if its from the tranny or from something else, feels like the tranny. any help or ideas would be awesome
#2
03-31-2010, 12:35 PM
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03-31-2010, 05:27 PM
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#4
03-31-2010, 09:29 PM
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It's not necessarily in limp mode.....
The governor solenoid and the governor pressure sensor control everything with the shifting.
They're a VERY common problem.
The good thing is, they're also easy to change.
Click the link below and go down to transmission and drivetrain. I have a DIY in there for changing the governor solenoid and pressure sensor.
http://www.doghousediesel.com/id13.html
The governor solenoid and the governor pressure sensor control everything with the shifting.
They're a VERY common problem.
The good thing is, they're also easy to change.
Click the link below and go down to transmission and drivetrain. I have a DIY in there for changing the governor solenoid and pressure sensor.
http://www.doghousediesel.com/id13.html
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04-01-2010, 11:53 AM
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#6
04-01-2010, 11:58 AM
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No problem at all.
It's an easy swap. If you can change the tranny fluid and filter, you can swap that solenoid and sensor.
Let me know if you need help finding the parts.
Some other symptoms that are associated with the sensor and solenoid are 1-2-1-2-1 shuffling under light throttle conditions, hard engagement under light throttle, slamming into 3rd, holding 2nd gear too long, etc.
The best way to see if the the sensor or solenoid is acting up though is to hook it to the StarScan or StarMobile and have it display the REQUESTED pressure from the ECM and the ACTUAL pressure.
At the 1 - 2 shift, you should see approx 28 psi.
At the 2 - 3 shift, you should see approx 58 psi.
At the 3 - 4 shift, you should see approx 95 psi.
At TC lock-up, you should see anywhere from 95 to 128 psi, based on the throttle input and engine RPM.
It's an easy swap. If you can change the tranny fluid and filter, you can swap that solenoid and sensor.
Let me know if you need help finding the parts.
Some other symptoms that are associated with the sensor and solenoid are 1-2-1-2-1 shuffling under light throttle conditions, hard engagement under light throttle, slamming into 3rd, holding 2nd gear too long, etc.
The best way to see if the the sensor or solenoid is acting up though is to hook it to the StarScan or StarMobile and have it display the REQUESTED pressure from the ECM and the ACTUAL pressure.
At the 1 - 2 shift, you should see approx 28 psi.
At the 2 - 3 shift, you should see approx 58 psi.
At the 3 - 4 shift, you should see approx 95 psi.
At TC lock-up, you should see anywhere from 95 to 128 psi, based on the throttle input and engine RPM.
Last edited by Coal Train; 04-01-2010 at 12:05 PM.