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 FOR OTHER TCM DTCS
1. Refer to the recorded DTCs.
  Are any other TCM DTCs set?
  
  Yes
  - Repair the other TCM DTCs. Refer to DTC TROUBLESHOOTING .
  - Perform the TRANSMISSION VERIFICATION TEST. Refer to 948TE-9HP48 TRANSMISSION VERIFICATION TEST .
  No
  - Go To 3
CHECK THE (F893) 5 VOLT CIRCUIT FOR OPEN/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 (F893) 5 Volt Supply circuit between the TCM harness connector and the Transmission Assembly harness connector.
  Is the resistance below 3.0 Ohms?
  
  Yes
  - Go To 4
  No
  - Repair the (F893) 5 Volt Supply circuit for an open circuit or high resistance.
  - Perform the TRANSMISSION VERIFICATION TEST. Refer to 948TE-9HP48 TRANSMISSION VERIFICATION TEST .
CHECK THE (T38) LINE PRESSURE SIGNAL CIRCUIT FOR OPEN/HIGH RESISTANCE
1. Measure the resistance of the (T38) Line Pressure Signal circuit between the TCM harness connector and the Transmission Assembly harness connector.
  Is the resistance below 3.0 Ohms?
  
  Yes
  
  Go To 5
  
  No
  - Repair the (T38) Line Pressure Signal circuit for an open or high resistance.
  - Perform the TRANSMISSION VERIFICATION TEST. Refer to 948TE-9HP48 TRANSMISSION VERIFICATION TEST .
CHECK THE (T191) SENSOR GROUND CIRCUIT FOR OPEN/HIGH RESISTANCE
1. Measure the resistance of the (T191) Sensor Ground circuit between the TCM harness connector and the Transmission Assembly harness connector.
  Is the resistance below 3.0 Ohms?
  
  Yes
  
  Go To 6
  
  No
  - Repair the (T191) Sensor Ground circuit for an open circuit or high resistance.
  - Perform the TRANSMISSION VERIFICATION TEST. Refer to 948TE-9HP48 TRANSMISSION VERIFICATION TEST .
CHECK (T38) LINE PRESSURE SIGNAL CIRCUIT FOR A SHORT TO GROUND OR ANOTHER CIRCUIT
1. Check for continuity between ground and the (T38) Line Pressure Signal circuit at the TCM harness connector.
2. Check for continuity between the (T38) Line Pressure Signal circuit and all other circuits at the TCM harness connector.
  Is there continuity between the (T38) Line Pressure Signal circuit and ground or any other circuit?
  
  Yes
  - Repair the (T38) Line Pressure Signal circuit for a short to ground or another circuit.
  - Perform the TRANSMISSION VERIFICATION TEST. Refer to 948TE-9HP48 TRANSMISSION VERIFICATION TEST .
  No
  
  Go To 7
CHECK INTERNAL HARNESS AND CONNECTIONS
1. Check the Transmission internal wiring harness and Line Pressure Sensor electrical connections for open circuits, shorts, and loose connections.
  Were any problems found?
  
  Yes
  - Repair the condition as necessary.
  - Perform the TRANSMISSION VERIFICATION TEST. Refer to 948TE-9HP48 TRANSMISSION VERIFICATION TEST .
  No
  
  Go To 8
CHECK LINE PRESSURE SENSOR RESISTANCE
NOTE:
The Line Pressure Sensor must be at room temperature to perform the next test.
1. Measure the resistance of the Line Pressure Sensor between terminal 15 and terminal 16 at the Transmission side of the Transmission Assembly harness connector.
  Is the resistance between 4.6 and 3.0 Ohms?
  
  Yes
  - Go To 9
  No
  - Replace the Transmission Line Pressure Sensor in accordance with the Service Information.
  - Perform the TRANSMISSION VERIFICATION TEST. Refer to 948TE-9HP48 TRANSMISSION VERIFICATION TEST .
CHECK THE TRANSMISSION FOR MECHANICAL PROBLEMS
1. Check the Transmission for mechanical problems. Refer to DIAGNOSIS AND TESTING .
  Did the Transmission have any mechanical problems?
  
  Yes
  - Repair as necessary in accordance with the Service Information.
  - Perform the TRANSMISSION VERIFICATION TEST. Refer to 948TE-9HP48 TRANSMISSION VERIFICATION TEST .
  No
  - Go To 10
CHECK RELATED HARNESS CONNECTIONS
1. Disconnect all TCM harness connectors.
2. Disconnect all related in-line harness connections (if equipped).
3. Disconnect the related component harness connectors.
4. Inspect harness connectors, component connectors, and all male and female terminals for the following conditions:
  - Proper connector installation.
  - Damaged connector locks.
  - Corrosion.
  - Other signs of water intrusion.
  - Weather seal damage (if equipped).
  - Bent terminals.
  - Overheating due to a poor connection (terminal may be discolored due to excessive current draw).
  - Terminals that have been pushed back into the connector cavity.
  - Perform a terminal drag test on each connector terminal to verify proper terminal tension.
  Repair any conditions that are found.
5. Reconnect all TCM harness connectors. Be certain that all harness connectors are fully seated and the connector locks are fully engaged.
6. Reconnect all in-line harness connectors (if equipped). Be certain that all connectors are fully seated and the connector locks are fully engaged.
7. Reconnect all related component harness connectors. Be certain that all connectors are fully seated and the connector locks are fully engaged.
8. With the scan tool, erase DTCs.
9. 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.
10. With the scan tool, read TCM DTCs.
  Did the DTC return?
  
  Yes
  - Replace the TCM in accordance with the Service information. Refer to MODULE, TRANSMISSION CONTROL (TCM), REMOVAL AND INSTALLATION .
  - Perform the TRANSMISSION VERIFICATION TEST. Refer to 948TE-9HP48 TRANSMISSION VERIFICATION TEST .
  No
  - Perform the TRANSMISSION VERIFICATION TEST. Refer to 948TE-9HP48 TRANSMISSION VERIFICATION TEST .
  - Test complete.