Diagnostic Test
IMPORTANT: 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.
- CHECK FOR ENGINE COOLING DTCS
- 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 DIAGNOSTIC CODE INDEX .
No
- Go To 2
- With the scan tool, read Powertrain Control Module (PCM) DTCs.
- CHECK FOR OTHER TRANSMISSION DTCS
- With the scan tool, read Transmission Control Module (TCM) DTCs and record on the repair order.
Are any other TCM DTCs set?
Yes
- Repair other TCM DTCs. Refer to 948TE/9HP48 AUTOMATIC TRANSMISSION - DIAGNOSTIC CODE INDEX .
No
- Go To 3
- With the scan tool, read Transmission Control Module (TCM) DTCs and record on the repair order.
- CHECK FOR AN ACTIVE DTC
- With the scan tool, read TCM DTCs.
- Record the Event Data and Environmental Data.
- With the scan tool, erase DTCs.
- 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.
- 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
- Turn the ignition off.
- Disconnect the TCM harness connector.
- Disconnect the Transmission Assembly harness connector.
- Connect a jumper wire between the (T819) Transmission Temperature Signal circuit and the (T23) Sensor Ground circuit at the Transmission Assembly harness connector.
- 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 TRANSMISSION VERIFICATION TEST .
- CHECK TRANSMISSION TEMPERATURE SENSOR CIRCUITS FOR A SHORT TO GROUND
- 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 (T23) Sensor Ground circuit for a short to ground.
- Perform the TRANSMISSION VERIFICATION TEST. Refer to TRANSMISSION VERIFICATION TEST .
No
- Go To 6
- With the jumper wire still connected, check for continuity between ground and the (T819) Transmission Temperature Signal circuit at the TCM harness connector.
- CHECK THE (T819) TRANSMISSION TEMPERATURE SIGNAL CIRCUIT FOR A SHORT TO ANOTHER CIRCUIT
- Remove the jumper wire from the Transmission Assembly harness connector.
- 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 TRANSMISSION VERIFICATION TEST .
No
- Go To 7
- CHECK THE (T23) SENSOR GROUND CIRCUIT FOR A SHORT TO ANOTHER CIRCUIT
- 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 TRANSMISSION VERIFICATION TEST .
No
- Go To 8
- Check for continuity between the (T23) Sensor Ground circuit and all other circuits at the TCM harness connector.
- VERIFY TRANSMISSION TEMPERATURE SENSOR RESISTANCE / TEMPERATURE CORRELATION
- Measure the resistance between (T819) Transmission Temperature Signal terminal and (T23) Sensor Ground terminal at the Transmission Assembly harness connector (Transmission side).
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 internal wiring harness in accordance with the Service Information.
- Perform the TRANSMISSION VERIFICATION TEST. Refer to TRANSMISSION VERIFICATION TEST .
- Measure the resistance between (T819) Transmission Temperature Signal terminal and (T23) Sensor Ground terminal at the Transmission Assembly harness connector (Transmission side).
- CHECK (T118) PRESSURE CONTROL SOLENOID-LINE PRESSURE CIRCUIT FOR HIGH RESISTANCE
- Measure the resistance of the (T118) Pressure Control Solenoid-Line Pressure circuit between the TCM harness connector and the Transmission Assembly harness connector.
Is the resistance below 3.0 Ohms?
Yes
- Go To 10
No
- Repair the (T118) Pressure Control Solenoid-Line Pressure circuit for an open or high resistance.
- Perform the TRANSMISSION VERIFICATION TEST. Refer to TRANSMISSION VERIFICATION TEST .
- Measure the resistance of the (T118) Pressure Control Solenoid-Line Pressure circuit between the TCM harness connector and the Transmission Assembly harness connector.
- CHECK (F501) SOLENOID SUPPLY 1 CIRCUIT FOR HIGH RESISTANCE
- Measure the resistance of the (F501) Solenoid Supply 1 circuit between the TCM harness connector and the Transmission Assembly harness connector.
Is the resistance below 3.0 Ohms?
Yes
- Go To 11
No
- Repair the (F501) Solenoid Supply 1 circuit for an open or high resistance.
- Perform the TRANSMISSION VERIFICATION TEST. Refer to TRANSMISSION VERIFICATION TEST .
- Measure the resistance of the (F501) Solenoid Supply 1 circuit between the TCM harness connector and the Transmission Assembly harness connector.
- CHECK (T118) PRESSURE CONTROL SOLENOID-LINE PRESSURE CIRCUIT IN THE TRANSMISSION INTERNAL HARNESS FOR HIGH RESISTANCE
- Remove the Transmission Side Cover in accordance with the Service information.
- Disconnect the Line Pressure Solenoid harness connector.
- Measure the resistance of the (T118) Pressure Control Solenoid-Line Pressure circuit between the Transmission Assembly harness connector (Transmission side) and the Line Pressure Solenoid harness connector.
Is the resistance below 3.0 Ohms?
Yes
- Go To 12
No
- Repair the (T118) Pressure Control Solenoid-Line Pressure circuit for an open or high resistance.
- Perform the TRANSMISSION VERIFICATION TEST. Refer to TRANSMISSION VERIFICATION TEST .
- CHECK (F501) SOLENOID SUPPLY 1 CIRCUIT IN THE TRANSMISSION INTERNAL HARNESS FOR HIGH RESISTANCE
- Measure the resistance of the (F501) Solenoid Supply 1 circuit between the Transmission Assembly harness connector (Transmission side) and the Line Pressure Solenoid harness connector.
Is the resistance below 3.0 Ohms?
Yes
- Replace the Line Pressure Control Solenoid in accordance with the Service Information.
- Perform the TRANSMISSION VERIFICATION TEST. Refer to TRANSMISSION VERIFICATION TEST .
No
- Repair the (F501) Solenoid Supply 1 circuit for an open or high resistance.
- Perform the TRANSMISSION VERIFICATION TEST. Refer to TRANSMISSION VERIFICATION TEST .
- Measure the resistance of the (F501) Solenoid Supply 1 circuit between the Transmission Assembly harness connector (Transmission side) and the Line Pressure Solenoid harness connector.