Diagnostic Test

CHECK FOR AN ACTIVE DTC
1. With the scan tool, read Transmission Control Module (TCM) DTCs and record on the repair order.
2. Record the Event Data and Environmental Data.
3. With the scan tool, erase DTCs.
4. Using the recorded Event and Environmental Data, along with the When Monitored and Set Conditions above, operate the vehicle in the conditions that set the DTC.
5. With the scan tool, read TCM DTCs.
  Did the DTC return?
  
  Yes
  - Go To 2
  No
  - Perform the TESTING FOR AN INTERMITTENT CONDITION procedure. Refer to TESTING FOR AN INTERMITTENT CONDITION .
CHECK TRANSMISSION RANGE SWITCH (TRS) CIRCUITS FOR AN OPEN OR HIGH RESISTANCE
1. Turn the ignition off.
2. Disconnect the TCM harness connector.
3. Disconnect the Transmission Assembly harness connector.
4. Measure the resistance of the following circuits between the TCM harness connector and the Transmission Assembly harness connector.
  - (T1) TRS T1 Signal
  - (T3) TRS T3 Signal
  - (T191) Sensor Ground
  - (F887) 9 Volt Supply
  Is the resistance below 3.0 Ohms for each circuit?
  
  Yes
  - Go To 3
  No
  - Repair the affected circuit(s) for an open or high resistance.
  - Perform the TRANSMISSION VERIFICATION TEST. Refer to 948TE-9HP48 TRANSMISSION VERIFICATION TEST .
CHECK PARK PAWL FOR MECHANICAL PROBLEMS
1. Remove the Valve Body and Inspect the Park Pawl and associated hardware for binding and damage. Refer to VALVE BODY, REMOVAL AND INSTALLATION .
  Were any problems found?
  
  Yes
  - Repair the condition in accordance with the Service Information.
  - Perform the TRANSMISSION VERIFICATION TEST. Refer to 948TE-9HP48 TRANSMISSION VERIFICATION TEST .
  No
  - Replace the Park Pawl Sensor in accordance with the service Information.
  - Perform the TRANSMISSION VERIFICATION TEST. Refer to 948TE-9HP48 TRANSMISSION VERIFICATION TEST .