Diagnostic Test

CHECK FOR AN ACTIVE DTC
1. With the scan tool, read all 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 THE (T54) TRANSMISSION TEMPERATURE SIGNAL AND THE (T820) SENSOR GROUND CIRCUIT OPERATION
1. Turn the ignition off.
2. Disconnect the Transmission Assembly harness connector.
3. Turn the ignition on.
4. Measure the voltage between the (T54) Transmission Temperature Signal circuit and the (T820) Sensor Ground at the Transmission Assembly harness connector.
  Is the voltage above 4.8 volts?
  
  Yes
  - Go To 5
  No
  - Go To 3
CHECK (T54) TRANSMISSION TEMPERATURE SENSOR CIRCUIT FOR AN OPEN
1. Turn the ignition off.
2. Disconnect the TCM harness connector.
3. Measure the resistance of the (T54) Transmission Temperature Signal circuit between the TCM harness connector and at the Transmission Assembly harness connector.
  Is the resistance below 3.0 Ohms?
  
  Yes
  - Go To 4
  No
  - Repair (T54) Transmission Temperature Signal circuit for an open.
  - Perform the TRANSMISSION VERIFICATION TEST. Refer to TRANSMISSION VERIFICATION TEST - 948TE 9HP48 .
CHECK (T820) GROUND CIRCUIT FOR AN OPEN
1. Measure the resistance of the (T820) Sensor Ground circuit between the TCM harness connector and the at the Transmission Assembly harness connector.
  Is the resistance below 3.0 Ohms?
  
  Yes
  - Go To 6
  No
  - Repair the (T820) Sensor Ground circuit for an open.
  - Perform the TRANSMISSION VERIFICATION TEST. Refer to TRANSMISSION VERIFICATION TEST - 948TE 9HP48 .
CHECK THE (T54) TRANSMISSION TEMPERATURE SIGNAL CIRCUIT FOR A SHORT TO ANOTHER CIRCUIT
1. Disconnect the TCM harness connector.
2. Check for continuity between the (T54) Transmission Temperature Signal circuit and all other circuits at the TCM harness connector.
  Is there continuity between the (T54) Transmission temperature signal circuit and any other circuit?
  
  Yes
  - Repair the (T54) Transmission Temperature Signal circuit for a short to another circuit.
  - Perform the TRANSMISSION VERIFICATION TEST. Refer to TRANSMISSION VERIFICATION TEST - 948TE 9HP48 .
  No
  - Go To 6

VERIFY TRANSMISSION TEMPERATURE SENSOR RESISTANCE / TEMPERATURE CORRELATION

Measure the resistance between (T54) Transmission Temperature Signal terminal and (T820) Sensor Ground terminal at the Transmission Assembly harness connector (Transmission side).

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

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 (TCM), REMOVAL .
Perform the TRANSMISSION VERIFICATION TEST. Refer to TRANSMISSION VERIFICATION TEST - 948TE 9HP48 .

Replace the Transmission Internal Wiring Harness in accordance with the Service Information. Refer to HARNESS, INTERNAL WIRE, REMOVAL .
Perform the TRANSMISSION VERIFICATION TEST. Refer to TRANSMISSION VERIFICATION TEST - 948TE 9HP48 .