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Home >> Jeep >> 2014 >> Wrangler Sahara, Standard Trans >> Repair and Diagnosis >> External Pages >> Different car >> Section 172 ((Powertrain Control Module (Pcm) - Electrical Diagnostics - 41TE Automatic Transmission)) >> DTC Troubleshooting >> P0731-Gear Ratio Error In 1ST >> Diagnostic Test

Diagnostic Test

WARNING: This page is about a different car, the 2016 Dodge Journey and 2015 Dodge Journey. However, it is still accessible from the selected car via links, so may be relevant.
  1. CHECK FOR OTHER TRANSMISSION RELATED DTCS 
    NOTE:

    Be certain to check for TCM software updates related to this complaint. If updates are available, reprogram the TCM and perform the TRANSMISSION VERIFICATION TEST. Refer to 40/41TE TRANSMISSION VERIFICATION TEST  .

    1. With a scan tool, read Transmission DTCs.

      Are there any Loss of Prime, Line Pressure Sensor and/or Speed Sensor DTCs present?

      Yes 

      • Repair the other Transmission related DTC(s) in accordance with the appropriate Service Information. Refer to DIAGNOSTIC CODE INDEX  .

      No 

      • Go to  2.
  2. CHECK IF THIS MALFUNCTION IS CURRENT 
    1. With the scan tool, perform the 1st Gear Clutch Test. Follow the instructions on the scan tool.
    2. When instructed to increase the Throttle Angle or TPS Angle to 30°, do so for no more than a few seconds.
      CAUTION:

      Do not overheat the transmission.

      Did the Input Speed remain at zero during the 1st Gear Clutch Test?

      Yes 

      • Go To  3

      No 

      • Go To  6
  3. TEST DRIVE FOR TRANSMISSION SLIPPAGE 
    1. With the scan tool, read TCM DTCs.
    2. Record the Environmental Data, Event Data, and any DTCs.
    3. With the scan tool, erase DTCs.
    4. Using the recorded Environmental Data, along with the When Monitored and Set Conditions above, operate the vehicle in the conditions that set the DTC.

      Did the transmission slip during the test drive?

      Yes 

      • Go to  6.

      No 

      • Go to  4.
  4. TEST DRIVE WHILE OBSERVING THE SPEED SENSOR RPM VALUES ON THE SCAN TOOL 
    1. Observe the Input and Output Speed Sensor rpm values during the test drive.

      Did any of the Speed Sensor values read zero rpm with the vehicle in motion?

      Yes 

      • Refer to the appropriate DTC procedure in DIAGNOSTIC CODE INDEX  for the Speed Sensor that was reading zero while the vehicle was in motion.
        • Refer to the DTC P0716 procedure for the Input Speed Sensor.
        • Refer to the DTC P0721 procedure for the Output Speed Sensor.

        Refer to DIAGNOSTIC CODE INDEX  .

      No 

      • Go to  5.
  5. REVIEW EVENT DATA ON SCAN TOOL 
    NOTE:

    Gear Ratio DTCs can be set by problems with the Input and Output Speed Sensors and related circuits.

    1. Refer to the recorded Event Data to help identify the conditions in which the DTC was set.
      • If the Event Data shows fault P0731 was set in Park, Reverse, or Neutral, replace the Powertrain Control Module.
      • If the Event Data shows fault P0731 was set with the Input Speed Sensor rpm = zero, check the Input Speed Sensor and related wiring. Refer to the P0716 diagnostic procedures. Refer to DIAGNOSTIC CODE INDEX  .
      • If the Event Data shows fault P0731 was set with the Output Speed Sensor rpm = zero, check the Output Speed Sensor and related wiring. Refer to the P0721 diagnostic procedures. Refer to DIAGNOSTIC CODE INDEX  .
      • If the Event Data shows fault P0731 was set with line pressure significantly below desired line pressure, check for the cause of low line pressure (i.e., oil level, mis-installed or damaged primary filter or filter seal, sticking main regulator valve in pump, etc.).

      Were any problems found?

      Yes 

      No 

      • Go to  8.
  6. CHECK GEAR SHIFT LINKAGE 
    1. Check the gear shift linkage for proper adjustment and operation. Refer to the appropriate Service Information.

      Was the Gear Shift Linkage operating properly?

      Yes 

      • Go to  7.

      No 

  7. CHECK INTERNAL TRANSMISSION 
    1. Repair internal transmission as necessary. Refer to the appropriate Service Information.
    2. If there were any line pressure DTCs present along with this DTC, make sure to inspect the: Primary oil filter and seal, Transmission Oil Pump, and the Main regulator valve in accordance with the Service Information.
    3. Pay particular attention to the following list of possible causes when repairing the transmission:
      • Air check the UD and LR clutch passages for excessive leakage.
      • Check all of the components related to the UD and LR clutches, and the rear planetary gearset.
      • Check the UD and LR accumulator pistons and seals.
      • Check that the main regulator valve moves freely in its bore.
      • If the UD or LR clutch is burned but no cause is evident (such as a cut piston seal, cracked sump filter, stuck regulator valve, etc.) replace the solenoid/pressure switch assembly.
      • Inspect the Oil Pump.
      • Inspect the input shaft and UD shaft.

      Repair 

      NOTE:

      If the UD clutch has failed but no obvious cause is found (such as a cut piston seal, broken seal ring, stuck regulator valve, low line pressure in Event Data, etc.) replace the Transmission Solenoid/TRS Assembly in addition to any necessary internal repairs.

  8. CHECK WIRING, CONNECTORS, AND GEAR SHIFT LINKAGE OPERATION 
    1. The conditions necessary to set the DTC are not present at this time.
    2. Using the schematics as a guide, inspect the wiring and connectors specific to this circuit.
    3. Wiggle the wires while checking for shorted and open circuits.
    4. Check for any Service Bulletins that may apply.
    5. Check the gear shift linkage for proper adjustment and operation. Refer to the appropriate Service Information.

      Were there any problems found?

      Yes 

      No 

      • Test complete.
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