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Mopar Certified
Mopar Certified, Dodge Technician
Category: Dodge
Satisfied Customers: 11332
Experience:  24 Year Chrysler/Dodge Certified Specialist
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2000 Dodge: 40 starts shifting back and forth out of overdrive

Resolved Question:

My 2000 Dodge Diesel 3500 has a problem with the transmission. At about 40 mph, it starts shifting back and forth out of overdrive. Can you help?
Submitted: 5 years ago.
Category: Dodge
Expert:  Mopar Certified replied 5 years ago.
Welcome to Just Answer Dodge my name isXXXXX realize that all my answers are based solely on the info you provide me......

There are a mutitude of reasons why this may be occuring.

The PCM controls the TCC solenoid while monitoring various sensors. BATTERY AND CABLES: Check battery condition and battery cable connections. Check main ground circuit for the PCM. Repair loose or corroded connections. If dual batteries are used verify batteries are properly matched and are in good operating condition. STEP 3): GENERATOR: Evaluate condition with generator wiring harness disconnected. Generator and/or generator wiring harness may produce excessive radio frequency interference (RFI) which can interfere with PCM input signals. MODELS WITH CUMMINS DIESEL ENGINE: Fuel transfer pump may also produce excessive RFI. To help determine if the fuel transfer pump is a concern, disable the vehicles charging system. Remove the surface charge from the batteries by turning on the head lights; bring battery voltage down to about 12 volts. Test drive the vehicle. If the vehicle stops surging in and out of lock up chances are the fuel transfer is producing RFI. STEP 4): PCM SENSORS: Check all related PCM sensor inputs. [1]: Engine coolant temp must be above 120 degrees. [2]: Trans fluid temp must be above 60 and below 272 degrees F. (varies slightly depending on model). [3]: Vehicle speed must be above 32 mph. [4]: Trans must be operating in 3rd gear. [5]: Brake pedal switch must be open indicating brake pedal not applied. [6]: Park / neutral switch signal to PCM must not be grounded which would indicate the trans is not in gear. [7]: Engine RPM signal must not be erratic. 1998 ? 2000 MY vehicles monitor the crank position sensor with the The DRBIII® lab scope. 2001 ? 2005 MY vehicles monitor the cam position sensor with the DRBIII® lab scope. [8]: Throttle position sensor (TPS / APPS) signal must not be erratic.
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