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Home >> Jeep >> 2020 >> Grand Cherokee Trackhawk >> Repair and Diagnosis >> External Pages >> Different car >> Section 272 (68RFE Automatic Transmission - DTCS P0218-00 To P0871-00 - 2500HD & 3500HD) >> DTC Troubleshooting >> P0740-00-TCC Out Of Range >> Diagnostic Test

Diagnostic Test

WARNING: This page is about a different car, the 2019 RAM 3500 HD and 2019 RAM 2500 HD. However, it is still accessible from the selected car via links, so may be relevant.
  1. CHECK FOR RELATED DTC P0750 
    1. With the scan tool, read DTCs.

      Is the DTC P0750 present also?

      Yes 

      No 

      • Go To  2
  2. CHECK IF THE DTC IS ACTIVE 
    1. With the scan tool, read and RECORD ALL  Transmission DTCs. After recording DTCs, erase DTCs.
    2. Drive the vehicle until the transmission temperature is at least 43° C or 110° F and the engine temperature at least 49° C or 120° F.
    3. Perform the following steps 3 times.
    4. Using the electronic Range Select (ERS) to place the transmission in 3rd gear.
    5. While monitoring the Torque convertor slip on the scan tool, accelerate smoothly at light to moderate throttle from 1200 to 2500 engine RPM and watch for TCC engagement.
      NOTE:

      Normal torque converter clutch slippage is 0 (± 20 RPM) in full lock-up.

      Pick the one that best describes your findings:

      TCC State remained at "Unlock" (controller never commanded TCC engagement) 

      • Go To  3

      Torque Converter Slip dropped properly to 0 (± 20 RPM) 

      • Go To  4

      TCC State showed "Transitioning" or "Full EMCC", but there was little or no change in T/C Slip 

      • Go To  5

      TCC tried to engage but had significant positive slip (60-150 RPM) 

      • Replace the Torque Converter and remove inspect the Transmission Oil Pump Assembly in accordance with the Service Information.
        NOTE:

        Check the input shaft end play before removing the pump. HOLD the input shaft during pump removal to prevent thrust bearings in the input clutches from falling out of position. Split the pump assembly and inspect for torque converter debris. Clean as necessary. Verify that the Torque Converter Switch Valve and the Torque Converter Clutch Control Valve (located in the Transmission Oil Pump Valve Body) are not sticking in their bores. Reinstall Transmission Oil Pump Assembly and verify proper input shaft end play.

      • Perform the TRANSMISSION VERIFICATION TEST. Refer to TRANSMISSION VERIFICATION TEST .
  3. CHECK FOR TCC ENGAGEMENT COMMANDED 
    1. Verify that the transmission temperature is at least 43° C or 110° F and the engine temperature at least 49° C or 120° F.
    2. Using the scan tool, monitor the "Target Gear TCC State" in the following steps.
    3. Road test the vehicle. Using the ERS in ERS "3", ERS "4", ERS "5", and Drive with an engine speed up to 2500 RPM in each position.

      Pick the one that best describes your findings:

      TCC would engage properly when commanded 

      • Go To  4

      TCC would NOT engage properly when commanded 

      • Go To  5

      Target Gear TCC State remained in the "Unlock" state continuously 

      NOTE:

      This transmission is equipped with a solenoid for the Torque Converter Clutch (TCC) that is a Variable Force Solenoid (VFS) with close tolerance Pressure/Inductance (PI) curve. If replacing the PCM, it is necessary to transfer the PI data from the old PCM to the new PCM using the scan tool. If the PCM being replaced is non-responsive, the PI data can be retrieved from a 2-D bar code on the exterior of the transmission case. This is done with the scan tool using the "Program Torque Converter Solenoid PI Curve" routine.

      Early build transmissions will have the 2-D barcode label on the right side of the transmission case. Late build transmissions will have the label attached to a machined pad at the top of the case, near the rear of the transmission. The data must be entered into the scan tool in order to upload the information to the PCM. In the event that the exterior BAR code is missing, or it is suspected that the valve body or TCC solenoid has been replaced without uploading the correct PI data into an existing PCM, the transmission oil pan must be removed to retrieve the information from the 2-D bar code on the body of the TCC solenoid.

      • Using the schematics as a guide, check the Powertrain Control Module (PCM) terminals for corrosion, damage, or terminal push out. Pay particular attention to all power and ground circuits. If no problems are found, replace and program the PCM in accordance with the Service Information. Refer to REMOVAL AND INSTALLATION .
      • With the scan tool, perform Quick Learn.
      • Perform the TRANSMISSION VERIFICATION TEST. Refer to TRANSMISSION VERIFICATION TEST .
  4. CHECK WIRING AND CONNECTORS 
    1. The conditions necessary to set this DTC are not present at this time. Using the schematics as a guide, inspect the wiring and connectors specific to this circuit. Wiggle the wires while checking for shorts and open circuits.
    2. Using the schematics as a guide, inspect the wiring and connectors specific to this circuit.
    3. Wiggle the wires while checking for shorts and open circuits.
    4. With the scan tool, check the Event Data to help identify the conditions in which the DTC was set.

      Were there any problems found?

      Yes 

      No 

  5. CHECK THE L/R-TCC SOLENOID 
    1. With the scan tool, check for other transmission DTCs.

      Are the DTCs P1775 and P0841 present also?

      Yes 

      No 

      • Go To  6
  6. CHECK THE TORQUE CONVERTER AND/OR INTERNAL TRANSMISSION 
    NOTE:

    This transmission is equipped with a solenoid for the Torque Converter Clutch (TCC) that is a Variable Force Solenoid (VFS) with close tolerance Pressure/Inductance (PI) curve. It is necessary to update the TCC solenoid PI data in the PCM when replacing the TCC solenoid, Valve Body or Transmission assembly. This is done with the scan tool using the "Program Torque Converter Solenoid PI Curve" routine. The PI data is located on a 2-D BAR code etched on the body of the TCC solenoid. The data must be entered into the scan tool in order to upload the information to the PCM.

    When replacing the TCC solenoid or Valve Body, obtain the PI data before installing the transmission oil pan. When replacing the transmission, the PI data can be obtained from a 2-D bar code on the exterior of the new transmission. Early build transmissions will have the 2-D barcode label on the right side of the transmission case. Late build transmissions will have the label attached to a machined pad at the top of the case, near the rear of the transmission. If it is suspected that the valve body or TCC VFS has been replaced without uploading the correct PI data into the PCM, the transmission oil pan must be removed to retrieve the information from the 2-D bar code on the body of the TCC solenoid.

    1. Repair internal transmission as necessary.
    2. Check for the following possible causes. Refer to the Service information for the proper repair procedures.
    3. Inspect the Transmission Oil Pump Assembly. Note:  Check the input shaft end play before removing the pump. HOLD the input shaft during pump removal to prevent thrust bearings in the input clutches from falling out of position. Split the pump assembly and inspect for torque converter debris. Clean as necessary. Verify that the Torque Converter Switch Valve and the Torque Converter Clutch Control Valve (located in the Transmission Oil Pump Valve Body) are not sticking in their bores. Reinstall Transmission Oil Pump Assembly and verify proper input shaft end play.
    4. Check the Teflon seal rings on the input shaft. Note:  If one of the seal rings is cut, the loose piece will often lodge in the TCC switch valve, causing it to stick in its bore.
    5. If no problems are found, replace the Transmission Solenoid/TRS Assembly. Refer to ASSEMBLY, TRANSMISSION SOLENOID AND TRS, REMOVAL AND INSTALLATION .

      Repair 

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