Engine/Transmission (1998.5 - 2002) 47RE wont upshift cold After oil change!!

[RGianelli]

I hope anyone can give me suggestion. . I had a problem w my 47RE, 99 2500; I have changed oil and filter and then it wont upshift, I think from 2nd to 3rd when cold! only when cold and rarely when hot; rpms goes on to 2000 and speed 40kmh but not upshift.

I have changed: tried 100% synth transmission fluid and ATF+3

replaced output speed sensor(on the transmission)

replaced governor pressure sensor

replaced governor pressure solenoid

I still have the same problem!

Maybe it can be the valve body? maybe need to be cleaned?

remember that I haven't any problem before the oil change!

it difficult drive at max 40kmh untill transmission reach temp...



any help will be much apprecciate



rob

 

[JLandry]

Rob,



Have you checked the ECM and PCM for trouble codes using a code scanner? That might offer a clue as to what is malfunctioning.



I'm sure you've thought about this, but there's nothing about an oil change that should affect the operation of the transmission in any way. Did you do *anything* else to the truck at the same time you changed the oil? For example, did you unplug and reconnect any of the wiring harness connectors or sensors?



It's possible the wiring harness between the PCM and the transmission Output Speed Sensor has a fault.



To check this, first disconnect the middle black colored PCM wiring harness connector and unplug the Output Speed Sensor connector at the transmission then conduct the following tests:

• Measure the resistance of the Output Speed Sensor ground circuit between the pin 25 of the PCM harness connector and the Output Speed Sensor harness connector. The resistance should be below 5. 0 ohms. If not, there's a break in the ground circuit wire.
  
  
  
• Next, measure the resistance between the vehicle ground and the Output Speed Sensor GROUND circuit. If the resistance is below 5. 0 ohms, there's a short in the ground circuit wire.
  
  
  
• Next, measure the resistance between vehicle ground and the Output Speed Sensor SIGNAL circuit. If the resistance is below 5. 0 ohms, there's a short in the ground signal wire.
  
  
  
• Next, measure the resistance of the Output Speed Sensor Signal circuit between pin 28 of the PCM harness connector and the Output Speed Sensor harness connector. The resistance should be below 5. 0 ohms. If not, there's a break in the signal circuit wire.
  
  
  
• Next, measure the resistance between the terminals of the Output Speed Sensor. The resistance should be between 300. 0 and 1200. 0 ohms. This tests the Speed Sensor itself.
  
  
  
• Now turn the ignition On, but do not start the engine (leave PCM and Speed Sensor unplugged).
  
  
  
• Measure for any voltage present on the Output Speed Sensor GROUND circuit in the Output Speed Sensor harness connector. There should be no voltage present. If there is, you have a short in the ground circuit.
  
  
  
• Next, measure for any voltage present on the Output Speed Sensor SIGNAL circuit in the Output Speed Sensor harness connector. There should be no voltage present. If there is, you have a short in the signal circuit.
  

Another area to check is the transmission temperature sensor circuit:

• Disconnect the middle black colored PCM wiring harness connector and unplug the Transmission Solenoid Assembly harness connector.
  
  
  
• Measure the resistance between vehicle ground and pin 2 (the 5-volt Supply circuit) in the Transmission Solenoid Assembly harness connector. The resistance should be above 100 kohms. If not, there's a short to ground in this circuit.
  
  
  
• Next, measure the resistance between pin 2 (the 5-volt Supply circuit) and the pin 3 (Sensor Ground circuit) in the Transmission Solenoid Assembly harness connector. The resistance should be above 100 kohms. If not, there's a short between these two circuits.
  
  
  
• Next, measure the resistance between vehicle ground and pin 8 (the Transmission Temperature Sensor Signal circuit) in the of the Transmission Solenoid Assembly harness connector. The resistance should be above 100 kohms. If not, there's a short between these circuits.
  
  
  
• Next, measure the resistance between pin 8 (the Transmission Temperature Sensor Signal circuit) and pin 3 (Sensor Ground circuit) in the Transmission Solenoid Assembly harness connector. The resistance should be above 100 kohms. If not, there's a short between these circuits.
  
  
  
• Next, remove the transmission oil pan. Disconnect the Governor Pressure/Transmission Temperature Sensor connector. Measure the resistance between ground and pin 2 (the 5-volt Supply circuit) at the Governor Pressure/Transmission Temperature Sensor connector. The resistance should be above 100 kohms.
  
  
  
• Next, measure the resistance between pin 2 (the 5-volt Supply circuit) and pin 3 (the Sensor Ground circuit) in the Governor Pressure/Transmission Temperature Sensor connector. The resistance should be above 100 kohms.
  
  
  
• Next, measure the resistance between vehicle ground and the pin 8 (Transmission Temperature Sensor Signal circuit) at the Governor Pressure/Transmission Temperature Sensor connector. The resistance shoud be above 100 kohms.
  
  
  
• Next, measure the resistance of the Transmission Temperature Sensor...
  
  
  
  
  Acceptable Sensor Resistance Ranges in OHMS
  
  
  
  Sensor Temperature Minimum Maximum
  
  -40°C (-40°F) 1094 1176
  
  0°C (32°F) 1587 1672
  
  25°C (77°F) 1960 2040
  
  70°C (158°F) 2709 2860
  
  100°C (212°F) 3284 3500
  
  120°C (120°F) 3684 3950
  
  150°C (302°F) 4110 4450
  
  
  
  The resistance should be between the specifications for the sensor and the current ambient temperature.​

Another wild idea:



Try swapping out the transmission control relay (possibly labeled "TRANS")with another non-essential relay (wipers) in the PDC (Power Dist. Center) on the driver's fender under the hood.



If all the above tests check out fine, then it's possible the PCM needs to be replaced or reprogrammed.



Good luck,



John L.

 

[RGianelli]

I've an AutoXRay EZRead 1000 code scanner but I don't know if it works good with my cummins; No code from the OBD II. I'll see transmission codes from the obd II port??

thanks a lot for the great tech! very helpful, I'll try even this. Maybe the Valve Body needs to be cleaned? I bought my truck used 8months ago and don't know if the last owner never changed the atf... bought with 82000miles

I'll check connection at PCM



rob

 

[RGianelli]

Dropped down the valve body today, just for cleaning, found a BROKE ACCUMULATOR SPRING in the 3-4 Acummulator Housing in the lower valve body! I think this is my problem. The broke spring has damaged a bit the piston... now looking for parts. .