Diagnostic Test

CHECK FOR AN ACTIVE DTC
1. With the scan tool, read 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
  - Go To 10
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 the TRANSMISSION CONTROL MODULE (TCM) - DIAGNOSTIC CODE INDEX article .
  - Perform the TRANSMISSION VERIFICATION TEST. Refer to TRANSMISSION VERIFICATION TEST - 948RE 9HP48 .
  No
  - Go To 3
CHECK THE (T376) 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 (T376) 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 (T376) 5-Volt Supply circuit for an open circuit or high resistance.
  - Perform the TRANSMISSION VERIFICATION TEST. Refer to TRANSMISSION VERIFICATION TEST - 948RE 9HP48 .
CHECK THE (T377) OIL PRESSURE SIGNAL CIRCUIT FOR OPEN/HIGH RESISTANCE
1. Measure the resistance of the (T377) Oil 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 (T377) Oil Pressure Signal circuit for an open or high resistance.
  - Perform the TRANSMISSION VERIFICATION TEST. Refer to TRANSMISSION VERIFICATION TEST - 948RE 9HP48 .
CHECK THE (T917) SENSOR GROUND CIRCUIT FOR OPEN/HIGH RESISTANCE
1. Measure the resistance of the (T917) 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 (T917) Sensor Ground circuit for an open circuit or high resistance.
  - Perform the TRANSMISSION VERIFICATION TEST. Refer to TRANSMISSION VERIFICATION TEST - 948RE 9HP48 .
CHECK (T377) OIL PRESSURE SIGNAL CIRCUIT FOR A SHORT TO GROUND OR ANOTHER CIRCUIT
1. Check for continuity between ground and the (T377) Oil Pressure Signal circuit at the TCM harness connector.
2. Check for continuity between the (T377) Oil Pressure Signal circuit and all other circuits at the TCM harness connector.
  Is there continuity between the (T377) Oil Pressure Signal circuit and ground or any other circuit?
  
  Yes
  - Repair the (T377) Oil Pressure Signal circuit for a short to ground or another circuit.
  - Perform the TRANSMISSION VERIFICATION TEST. Refer to TRANSMISSION VERIFICATION TEST - 948RE 9HP48 .
  No
  
  Go To 7
CHECK INTERNAL HARNESS AND CONNECTIONS
1. Check the Transmission internal wiring harness and Oil 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 TRANSMISSION VERIFICATION TEST - 948RE 9HP48 .
  No
  
  Go To 8
CHECK OIL PRESSURE SENSOR RESISTANCE
NOTE:
The Oil Pressure Sensor must be at room temperature to perform the next test.
1. Measure the resistance of the Oil 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 5.0 Ohms?
  
  Yes
  - Go To 9
  No
  - Replace the Transmission Oil Pressure Sensor in accordance with the Service Information.
  - Perform the TRANSMISSION VERIFICATION TEST. Refer to TRANSMISSION VERIFICATION TEST - 948RE 9HP48 .
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 TRANSMISSION VERIFICATION TEST - 948RE 9HP48 .
  No
  
  NOTE:
  If this Electronic Control Unit (ECU) is being replaced with a new unit, a diagnostic scan tool MUST be used to align the PROXI configuration data into the new ECU. Follow the routine outlined in the diagnostic scan tool for PROXI Configuration Alignment under Body Control Module (BCM) Miscellaneous Functions menu.
  - Using the schematics as a guide, check the Transmission Control Module (TCM) terminals and connectors for corrosion, damage or pushed out terminals. Pay particular attention to the power and ground circuits. If no problems are found, replace the TCM and perform programming and PROXI Configuration Alignment procedures. Refer to MODULE, TRANSMISSION CONTROL, REMOVAL .
  - Perform the TRANSMISSION VERIFICATION TEST. Refer to TRANSMISSION VERIFICATION TEST - 948RE 9HP48 .
CHECK WIRING AND CONNECTORS
1. The conditions necessary to set the DTC are not present at this time.
2. Using the schematics as a guide, inspect the wiring and connectors specific to this circuit.
3. Wiggle the wires while checking for shorted and open circuits.
4. Check for any Service Bulletins that may apply.
  Were any problems found?
  
  Yes
  - Repair as necessary.
  - Perform the TRANSMISSION VERIFICATION TEST. Refer to TRANSMISSION VERIFICATION TEST - 948RE 9HP48 .
  No
  - Test complete.