Circuit/System Verification

WARNING:

Refer to Parking Brake and Drive Wheels Warning .

Ignition ON.
Verify with a scan tool there are no transmission internal mode switch (IMS) DTCs set.
- If IMS DTCs were set
  Refer to Diagnostic Trouble Code (DTC) List - Vehicle .
- If no IMS DTCs were set
Verify the gear shift lever position matches the scan tool TCM Internal Mode Switch parameter while slowly moving the gear shift lever from Park through all ranges.
- If the displayed values are not correct
  Refer to Range Selector Lever Cable Adjustment .
- If the displayed values are correct
Verify the scan tool Driver Shift Control Mode parameter displays Inactive with the transmission shift lever in Park, Reverse, Neutral, and Drive, and Active with the shift lever left of the D or manual mode position.
- If the Driver Shift Mode parameter does not display the correct values
  Refer to Circuit/System Testing below.
- If the Driver Shift Mode parameter displays the correct values
Shift lever left of the D position.
Verify the scan tool Up and Down Shift Switch parameter changes from None to Upshift when the tap up button is pressed, and from None to Downshift when the tap down button is pressed.
- If parameter values are not correct
  Refer to Circuit/System Testing below.
- If parameter values are correct
After performing the above steps, verify that the DTC does not reset by operating the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions you observe from the Freeze Frame/Failure Records data. If the vehicle passes the Circuit/System Verification procedure, then STOP. Do not perform the Circuit/System Testing or Component Testing as this may result in an unnecessary part replacement. Refer to Testing for Intermittent Conditions and Poor Connections .