48RE Automatic Transmission - Diesel
P0711-TRANS TEMP SENSOR, NO TEMP RISE AFTER START (DIESEL)
For a complete wiring diagram refer to Diagrams/Electrical. Electrical Diagrams
Theory of Operation
The Transmission Temperature Sensor is used to sense when the transmission temperature is too hot or too cold to operate overdrive and/or the torque convertor clutch. When the transmission sensor detects a temperature below 0� C (32� F), overdrive and the torque convertor clutch are disabled. When the detected temperature is above 127� C (260� F), overdrive is disabled and 3rd gear with TCC is engaged, this strategy is used to increase transmission fluid flow to help cool the transmission.
- When Monitored:
Continuously with the ignition on and the engine running.
- Set Condition:
The DTC will set after two consecutive trips in which the transmission oil temperature is greater than 5� C (40� F) and the transmission oil temperature does not rise more than 8� C (16� F) after 20 minutes of run time with a vehicle speed greater than 48 km/h (30 mph). The DTC will also set if the engine temperature is greater than 38� C (100� F) with the transmission oil temperature greater than 127� C (260� F).
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Pre-Diagnostic Checkout (Diesel)
Diagnostic Test
1. CHECK IF THE DTC IS CURRENT
Ignition on, engine not running.
With the scan tool, read Engine DTCs.
Record the Freeze Frame data for the reported DTC.
With the scan tool, erase DTCs.
Turn the ignition off to the lock position.
Using the Freeze Frame data recorded earlier, try to duplicate the conditions in which the DTC originally set.
NOTE: It may be necessary to road test the vehicle to duplicate the original set conditions.
With the scan tool, read Engine DTCs.
Did the DTC reset?
Yes
- Go To 2
No
- Go To 6
2. CHECK FOR OTHER TRANSMISSION DTCS
Does the scan tool show any Park/Neutral DTCs?
Yes
- Refer to the Transmission category and perform the appropriate symptom(s).
No
- Go To 3
3. COMPARE THE TRANSMISSION TEMPERATURE TO ENGINE COOLANT TEMPERATURE
NOTE: To test the transmission temperature sensor, the engine and transmission temperature must be at or below 29.4� C (85� F).
With the scan tool, read the Transmission and Engine temperatures.
Is the transmission temperature within 5� C (9� F) of the engine coolant temperature?
Yes
- Go To 4
No
- Go To 5
4. CHECK IF THE TRANSMISSION TEMPERATURE INCREASES 15 DEGREES OVER 10 MINUTE PERIOD
NOTE: To test the transmission temperature sensor, the engine and transmission temperature must be at or below 29.4� C (85� F).
CAUTION: Apply the parking brake.
Start the engine, firmly apply the brakes and allow the engine to idle in Drive.
With the scan tool, monitor the Transmission Temperature.
NOTE: If the transmission temperature sensor is working properly, the transmission temperature should rise at least 8� C (15� F) within a ten minute period.
Did the transmission temperature increase at a steady rate and rise at least 8� C (15� F) over a 10 minute period?
Yes
- Go To 6
No
- Go To 5
5. CHECK THE TRANSMISSION TEMPERATURE SENSOR
Turn the ignition off to the lock position.
Remove the Transmission Oil Pan.
Disconnect the Governor Pressure Sensor harness connector internal to the transmission.
NOTE: Check connectors - Clean/repair as necessary.
Measure the resistance of the Transmission Temperature Sensor between the (T54) Transmission Temperature Sensor Signal circuit and the (K900) Sensor Ground circuit.
Using the chart at 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
- Test Complete.
No
- Replace the Governor Pressure/Transmission Temperature Sensor.
- Perform RE TRANSMISSION VERIFICATION TEST VER - 1 (DIESEL). Transmission Verification Test
6. INTERMITTENT WIRING AND CONNECTORS
The conditions necessary to set this DTC are not present at this time.
Use the Freeze Frame Data to help duplicate the conditions in which the DTC originally set. Pay particular attention to the DTC set conditions, such as, VSS, MAP, ECT, and Load.
Using the schematics as a guide, visually inspect the related wiring harness. Look for any chafed, pierced, pinched, or partially broken wires.
Visually inspect the related wiring harness connectors. Look for broken, bent, pushed out, or corroded terminals.
Wiggle the wiring and connectors while checking for any possible open or shorted circuits.
Check for any Service Information Tune-ups or Technical Service Bulletins that may apply.
Were there any problems found?
Yes
- Repair as necessary.
- Perform RE TRANSMISSION VERIFICATION TEST VER - 1 (DIESEL). Transmission Verification Test
No
- Test Complete.