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 (T819) TRANSMISSION TEMPERATURE SIGNAL AND (T23) SENSOR GROUND CIRCUIT OPERATION
1. Turn the ignition off.
2. Remove the Transmission Valve Body and disconnect the Transmission Temperature Sensor harness connector. Refer to VALVE BODY, REMOVAL AND INSTALLATION .
3. Turn the ignition on.
4. Measure the voltage between the (T819) Transmission Temperature Signal circuit and the (T23) Sensor Ground.
  Is the voltage above 4.8 volts?
  
  Yes
  - Go To 5
  No
  - Go To 3
CHECK (T819) TRANSMISSION TEMPERATURE SENSOR CIRCUIT FOR AN OPEN
1. Turn the ignition off.
2. Disconnect the TCM harness connector.
3. Measure the resistance of the (T819) Transmission Temperature Signal circuit between the TCM harness connector and the Transmission Temperature Sensor harness connector.
  Is the resistance below 3.0 Ohms?
  
  Yes
  - Go To 4
  No
  - Repair (T819) Transmission Temperature Signal circuit for an open.
  - Perform the TRANSMISSION VERIFICATION TEST. Refer to 948TE-9HP48 TRANSMISSION VERIFICATION TEST .
CHECK (T23) GROUND CIRCUIT FOR AN OPEN
1. Measure the resistance of the (T23) Sensor Ground circuit between the TCM harness connector and the Transmission Temperature Sensor harness connector.
  Is the resistance below 3.0 Ohms?
  
  Yes
  - Go To 7
  No
  - Repair the (T23) Sensor Ground circuit for an open.
  - Perform the TRANSMISSION VERIFICATION TEST. Refer to 948TE-9HP48 TRANSMISSION VERIFICATION TEST .
CHECK THE (T819) TRANSMISSION TEMPERATURE SIGNAL CIRCUIT FOR A SHORT TO ANOTHER CIRCUIT
1. Disconnect the TCM 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 6

VERIFY TRANSMISSION TEMPERATURE SENSOR RESISTANCE / TEMPERATURE CORRELATION

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

TYPICAL VALUES FOR TRANSMISSION TEMPERATURE SENSOR
TEMPERATURE	APPROXIMATE RESISTANCE
-30°C (-22°F)	44000 Ohms ± 6600
10°C (50°F)	6455 Ohms ± 645
110°C (230°F)	247 Ohms ± 16
145°C (293°F)	111 Ohms ± 6

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 7

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.