Diagnostic Test

CHECK IF THE DTC IS ACTIVE
NOTE:
If the TCM detects and stores a DTC, the TCM also stores the vehicles operating conditions under which the DTC originally set. This information is located in scan tool under Environmental Data. Before erasing any stored DTCs, record any available data to assist in duplicating the conditions in which the DTC originally set.
1. Turn the ignition off to the lock position.
2. With the scan tool, erase Transmission DTC's.
3. Using the Environmental Data recorded earlier, try to duplicate the conditions in which the DTC originally set. It may be necessary to test drive the vehicle.
4. With the scan tool, read Transmission DTC's.
  Did the DTC P0743 reset?
  
  Yes
  - Go To 2
  No
  - Perform the TESTING FOR AN INTERMITTENT CONDITION procedure. Refer to TESTING FOR AN INTERMITTENT CONDITION .
CHECK THE (T75) TCC SOLENOID CONTROL CIRCUIT FOR AN OPEN
1. Turn the ignition off to the lock position.
2. Disconnect the TCM C2 harness connector.
3. Disconnect the Transmission Electrohydraulic Control Unit Assembly harness connector.
  NOTE:
  Check connectors - Clean/repair as necessary.
4. Measure the resistance of the (T75) TCC Solenoid Control circuit from the TCM C2 harness connector to the Transmission Electrohydraulic Control Unit Assembly harness connector.
  Is the resistance above 5.0 ohms?
  
  Yes
  - Repair the (T75) TCC Solenoid Control circuit for an open.
  - Perform NAG1 TRANSMISSION VERIFICATION TEST. Refer to NAG1 TRANSMISSION VERIFICATION TEST .
  No
  - Go To 3
CHECK THE (T75) TCC SOLENOID CONTROL CIRCUIT FOR A SHORT TO GROUND
1. Measure the resistance between ground and the (T75) TCC Solenoid Control circuit.
  Is the resistance below 5.0 ohms?
  
  Yes
  - Repair the (T75) TCC Solenoid Control circuit for a short to ground.
  - Perform NAG1 TRANSMISSION VERIFICATION TEST. Refer to NAG1 TRANSMISSION VERIFICATION TEST .
  No
  - Go To 4
CHECK THE (T75) TCC SOLENOID CONTROL CIRCUIT FOR A SHORT TO ANOTHER CIRCUIT
1. Measure the resistance between the (T75) TCC Solenoid Control circuit and all other circuits in the Transmission Electrohydraulic Control Unit Assembly harness connector.
  Is the resistance below 5.0 ohms between the (T75) TCC Solenoid Control circuit and any other circuit(s) in the Transmission Electrohydraulic Control Unit Assembly harness connector?
  
  Yes
  - Repair the (T75) TCC Solenoid Control circuit for a short to another circuit.
  - Perform NAG1 TRANSMISSION VERIFICATION TEST. Refer to NAG1 TRANSMISSION VERIFICATION TEST .
  No
  - Go To 5
CHECK THE INTERNAL (T78) SOLENOID SUPPLY CIRCUIT FOR AN OPEN
1. Remove the Electrohydraulic Control Unit in accordance with the Service Information. Refer to UNIT, ELECTROHYDRAULIC CONTROL, REMOVAL .
2. Remove the TCC Solenoid in accordance with the Service Information. Refer to UNIT, ELECTROHYDRAULIC CONTROL, DISASSEMBLY .
3. Measure the resistance of the (T78) Solenoid Supply circuit from the Transmission Electrohydraulic Control Unit Assembly connector to the solenoid connector.
  Is the resistance above 5.0 ohms?
  
  Yes
  - Replace the Electrical Connector Assembly in accordance with the Service Information. Refer to UNIT, ELECTROHYDRAULIC CONTROL, DISASSEMBLY .
  - Perform NAG1 TRANSMISSION VERIFICATION TEST. Refer to NAG1 TRANSMISSION VERIFICATION TEST .
  No
  - Go To 6
CHECK THE INTERNAL (T75) TCC SOLENOID CONTROL CIRCUIT FOR AN OPEN
1. Remove the Electrohydraulic Control Unit in accordance with the Service Information. Refer to UNIT, ELECTROHYDRAULIC CONTROL, REMOVAL .
2. Remove the TCC Solenoid in accordance with the Service Information. Refer to UNIT, ELECTROHYDRAULIC CONTROL, DISASSEMBLY .
3. Measure the resistance of the (T75) TCC Solenoid Control circuit from the Transmission Electrohydraulic Control Unit Assembly connector to the solenoid connector.
  Is the resistance above 5.0 ohms?
  
  Yes
  - Replace the Electrical Connector Assembly in accordance with the Service Information. Refer to UNIT, ELECTROHYDRAULIC CONTROL, DISASSEMBLY .
  - Perform NAG1 TRANSMISSION VERIFICATION TEST. Refer to NAG1 TRANSMISSION VERIFICATION TEST .
  No
  - Go To 7
CHECK THE INTERNAL (T75) TCC SOLENOID CONTROL CIRCUIT FOR A SHORT TO GROUND
1. Measure the resistance of the (T75) TCC Solenoid Control circuit from the Transmission Electrohydraulic Control Unit Assembly harness connector to the Valve Body.
  Is the resistance below 5 ohms?
  
  Yes
  - Replace the Electrical Connector Assembly in accordance with the Service Information. Refer to UNIT, ELECTROHYDRAULIC CONTROL, DISASSEMBLY .
  - Perform NAG1 TRANSMISSION VERIFICATION TEST. Refer to NAG1 TRANSMISSION VERIFICATION TEST .
  No
  - Go To 8
CHECK THE INTERNAL (T75) TCC SOLENOID CONTROL CIRCUIT FOR A SHORT TO ANOTHER CIRCUIT
1. Measure the resistance of the (T75) TCC Solenoid Control circuit from the Transmission Electrohydraulic Control Unit Assembly connector to all other circuits in the connector.
  Is the resistance below 5 ohms?
  
  Yes
  - Replace the Electrical Connector Assembly in accordance with the Service Information. Refer to UNIT, ELECTROHYDRAULIC CONTROL, DISASSEMBLY .
  - Perform NAG1 TRANSMISSION VERIFICATION TEST. Refer to NAG1 TRANSMISSION VERIFICATION TEST .
  No
  - Go To 9
CHECK THE TCC SOLENOID RESISTANCE
2. Measure the resistance of the TCC Solenoid between the (T75) TCC Solenoid Control circuit and the (T78) Solenoid Supply circuit at the TCC solenoid.
  Is the resistance of the TCC Solenoid between 2.0 and 4.0 ohms?
  
  Yes
  - Using the schematics as a guide, check the Transmission Control Module (TCM) terminals for corrosion, damage, or terminal push out. Pay particular attention to all power and ground circuits. If no problems are found, replace the TCM in accordance with the Service Information. Refer to MODULE, TRANSMISSION CONTROL (TCM), REMOVAL .
    .
  - Perform NAG1 TRANSMISSION VERIFICATION TEST. Refer to NAG1 TRANSMISSION VERIFICATION TEST .
  No
  - Replace the TCC Solenoid in accordance with the Service Information.
  - Perform NAG1 TRANSMISSION VERIFICATION TEST. Refer to NAG1 TRANSMISSION VERIFICATION TEST .