TRNW
Diagnostic Trouble Codes

45RFE Diagnostic Help


GENERAL INFORMATION

Code Description: P0705 - Check Shifter Signal
P0706 - Check Shifter Signal

Functional Operation; The Transmission Control Module (TCM) monitors a series of switches (C1 through C5) inside the Transmission Range Sensor (TRS) in order to determine shift lever postition. Each switch can either be open or closed, and each lever position has it's own unique combination of open and closed switches. This combination is referred to as the 'PRNDL code'. There are 12 valid PRNDL codes. Two for neutral, one for each drive gear position, and five transition-zone codes. Any other possible switch combination is called an 'invalid code'. If the TCM detects any invalid PRNDL code that lasts for more than .03 seconds, the code will set. The 'check engine' light will not illuminate, and the transmission will not go into limp mode. The customer may complain that all or none of the PRNDL lights in the dash were illuminated.

Possible Causes:

  • Failed Transmission Range Sensor
  • Worn code plate (rooster comb).
  • Broken, spread, or pushed in terminals in the TRS connector.
  • Broken, spread, or pushed in terminals in the TCM connector.
  • Open or shorted TRS T1 circuit
  • Open or shorted TRS T2 circuit
  • Open or shorted TRS T3 circuit
  • Open or shorted TRS T41 circuit
  • Open or shorted TRS T42 circuit
  • Excessive metallic debris in the transmission fluid
  • TCM - Internal Failure

    DIAGNOSTIC ROUTINES

    1. Be sure to perform the Preliminary Tests

    2. With a scan tool, perform the Shift Lever Position Test. If the test fails without giving a failure code, replace the TCM.

    3. With a scan tool, monitor the TRS sense circuits (C1 through C5).
      Move the shift lever from P to L, and watch for the circuits to change state. Perform tests of the circuit (below) which is not changing

    4. TRS T1 sense (C4):
      • Check the integrity of the TRS T1 sense circuit from the TCM harness connector to the Solenoid / TRS Assembly harness connector.
      • Check the TRS T1 sense circuit for a short to ground.
      • Check the TRS T1 sense circuit for a short to voltage.

    5. TRS T2 sense (C5):
      • Check the integrity of the TRS T2 sense circuit from the TCM harness connector to the Solenoid / TRS Assembly harness connector.
      • Check the TRS T2 sense circuit for a short to ground.
      • Check the TRS T2 sense circuit for a short to voltage.

    6. TRS T3 sense (C3):
      • Check the integrity of the TRS T3 sense circuit from the TCM harness connector to the Solenoid / TRS Assembly harness connector.
      • Check the TRS T3 sense circuit for a short to ground.
      • Check the TRS T3 sense circuit for a short to voltage.

    7. TRS T41 sense (C1):
      • Check the integrity of the TRS T41 sense circuit from the TCM harness connector to the Solenoid / TRS Assembly harness connector.
      • Check the TRS T41 sense circuit for a short to ground.
      • Check the TRS T41 sense circuit for a short to voltage.

    8. TRS T42 sense (C2):
      • Check the integrity of the TRS T42 sense circuit from the TCM harness connector to the Solenoid / TRS Assembly harness connector.
      • Check the TRS T42 sense circuit for a short to ground.
      • Check the TRS T42 sense circuit for a short to voltage.

    9. If the wiring checks out OK, replace the Transmission Solenoid / TRS Assembly

    10. If all other possible causes have been eliminated, replace the Transmission Control Module.
      - Perform the "QuickLearn" procedure.





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