LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Suzuki >> 2009 >> XL7 Premium, FWD >> Repair and Diagnosis >> Transmission >> Automatic Transmission >> Diagnostic Information and Procedures >> DTC P0634: Transmission Control Module (TCM) Overtemperature >> Circuit/System Verification
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Circuit/System Verification

  1. Ignition ON, review the Failure Records when the DTC set. Verify the scan tool ECT Sensor parameter is less than 125 °C (257 °F).
  2. Perform the TRANSMISSION FLUID CHECK  to verify correct fluid level and condition. The transmission fluid level should be within the crosshatch band and the transmission fluid should be red or dark brown.
  3. Perform the TRANSMISSION FLUID COOLER FLUSHING AND FLOW TEST  to verify proper transmission oil cooler flow.
  4. Operate the vehicle within the conditions for running and setting the DTC. Verify the scan tool TCM Temperature parameter is less than 146 °C (295 °F).
    • If greater than the specified range, inspect the transmission cooling system for the items list below and repair as necessary. If all the items test normal, replace the control solenoid (w/body and TCM) valve assembly:
      • Obstructions in the airflow of the radiator or transmission cooler
      • Kinked or damaged transmission fluid lines
      • Damage to the transmission cooler
    • Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.