Diagnostic Test

CHECK FOR ENGINE COOLING DTCS
NOTE:
Before performing this Diagnostic Test, be certain that there are no problems that could cause the Transmission to overheat. Check for restricted Transmission oil cooler and lines, air flow restrictions, and low Transmission fluid. Towing loads weighing more than the recommended towing capacity could cause excessively high Transmission temperatures.
1. With the scan tool, read Powertrain Control Module (PCM) DTCs.
  Are any engine cooling or Active Grille Shutter (AGS) DTCs set?
  
  Yes
  - Repair PCM DTCs. Refer to DTC TROUBLESHOOTING .
  No
  - Go To 2
CHECK FOR OTHER TRANSMISSION DTCS
1. With the scan tool, read Transmission Control Module (TCM) DTCs and record on the repair order.
  Are any other TCM DTCs set?
  
  Yes
  - Repair the other TCM DTCs. Refer to DTC TROUBLESHOOTING .
  No
  - Go To 3
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 4
  No
  - Perform the TESTING FOR AN INTERMITTENT CONDITION procedure. Refer to TESTING FOR AN INTERMITTENT CONDITION .
CHECK TRANSMISSION TEMPERATURE SENSOR CIRCUITS FOR HIGH RESISTANCE
1. Turn the ignition off.
2. Disconnect the TCM harness connector.
3. Remove the Transmission side cover in accordance with the Service Information and disconnect the Transmission temperature sensor harness connector.
4. Connect a jumper wire between the (T819) Transmission Temperature Signal circuit and the (T23) Sensor Ground circuit at the Transmission temperature sensor harness connector.
5. Measure resistance between (T819) Transmission Temperature Signal circuit and the (T23) Sensor Ground circuit at the TCM harness connector.
  Is the resistance below 3.0 Ohms?
  
  Yes
  - Go To 5
  No
  - Repair the (T819) Transmission Temperature Signal circuit or the (T23) Sensor Ground circuit for an open or high resistance.
  - Perform the TRANSMISSION VERIFICATION TEST. Refer to 948TE-9HP48 TRANSMISSION VERIFICATION TEST .
CHECK TRANSMISSION TEMPERATURE SENSOR CIRCUITS FOR A SHORT TO GROUND
1. With the jumper wire still connected, check for continuity between ground and the (T819) Transmission Temperature Signal circuit at the TCM harness connector.
  Is there continuity between ground and the (T819) Transmission Temperature Signal circuit?
  
  Yes
  - Repair the (T819) Transmission Temperature Signal circuit or the (T23) Sensor Ground circuit for a short to ground.
  - Perform the TRANSMISSION VERIFICATION TEST. Refer to 948TE-9HP48 TRANSMISSION VERIFICATION TEST .
  No
  - Go To 6
CHECK THE (T819) TRANSMISSION TEMPERATURE SIGNAL CIRCUIT FOR A SHORT TO ANOTHER CIRCUIT
1. Remove the jumper wire from the Transmission Temperature Sensor harness connector.
2. Check for continuity between the (T819) Transmission Temperature Signal circuit and all other circuits at the TCM harness connector.
  Is there continuity between the (T819) Transmission Temperature Signal circuit and any other circuit?
  
  Yes
  - Repair the (T819) Transmission Temperature Signal circuit for a short to another circuit.
  - Perform the TRANSMISSION VERIFICATION TEST. Refer to 948TE-9HP48 TRANSMISSION VERIFICATION TEST .
  No
  - Go To 7
CHECK THE (T23) SENSOR GROUND CIRCUIT FOR A SHORT TO ANOTHER CIRCUIT
1. Check for continuity between the (T23) Sensor Ground circuit and all other circuits at the TCM harness connector.
  Is there continuity between the (T23) Sensor Ground circuit and any other circuit?
  
  Yes
  - Repair the (T23) Sensor Ground circuit for a short to another circuit.
  - Perform the TRANSMISSION VERIFICATION TEST. Refer to 948TE-9HP48 TRANSMISSION VERIFICATION TEST .
  No
  - Go To 8

VERIFY TRANSMISSION TEMPERATURE SENSOR RESISTANCE / TEMPERATURE CORRELATION

Measure the resistance between (T819) Transmission Temperature Signal terminal and (T23) Sensor Ground terminal at the Transmission Temperature Sensor.

TEMPERATURE vs RESISTANCE
TEMPERATURE	RESISTANCE
-30°C (-22°F)	37, 400 - 50, 600 Ohms
10°C (50°F)	5, 810 - 7, 100 Ohms
110°C (230°F)	231 - 263 Ohms
145°C (293°F)	105 - 117 Ohms

Using the chart above, compare the Temperature Sensor temperature to the correlating resistance value.
Is the resistance within the specified range when the sensor is at the given temperature?

Yes
- Go To 9
No
- Replace the Transmission Temperature Sensor in accordance with the Service Information. Refer to HARNESS, INTERNAL WIRE, REMOVAL AND INSTALLATION .
- Perform the TRANSMISSION VERIFICATION TEST. Refer to 948TE-9HP48 TRANSMISSION VERIFICATION TEST .

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.