2ML70 - Automatic Transmission
DTC P0711, P0712, or P0713
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (Diagnostic System Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Strategy Based Diagnosis) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Diagnostic Procedure Instructions) provides an overview of each diagnostic category.
DTC Descriptors
DTC P0711
- Transmission Fluid Temperature (TFT) Sensor Performance
DTC P0712
- Transmission Fluid Temperature (TFT) Sensor Circuit Low Voltage
DTC P0713
- Transmission Fluid Temperature (TFT) Sensor Circuit High Voltage
Diagnostic Fault Information
Typical Scan Tool Data
Circuit/System Description
The primary source of heat in the transmission is the drive motor generators. The drive motor generators are cooled by the transmission fluid. Hot fluid exits the drive motor generators and flows to the transmission cooler supply line. The supply line connects to the cooler, which is in front of the radiator. The transmission fluid cooler pipe assembly is equipped with an internal thermostat that opens at 80°C (176°F) for optimum transmission operation and fuel economy. The transmission cooler pipe thermostat is part of the transmission fluid cooler pipe assembly, located near the transmission and is not serviced separately. From the cooler, the fluid returns through the transmission fluid cooler pipe assembly and enters the lubrication circuits. After lubricating the internal components, the fluid returns to the oil pan. The transmission fluid temperature sensor is located in the control solenoid valve assembly and is not serviced separately.
Conditions for Running the DTC
* No OSS DTCs P0721, P0722, or P0723, P077B, P215C.
* The engine run time is greater than 5 seconds.
* The system voltage is 11-18 V.
* The estimated drive motor power loss is greater than 0.4 kw for 200 seconds.
* The OSS is greater than 200 RPM for 5 seconds.
P0711
* The Trans. Fluid Temp. parameter is -50 to +21°C (-58 to +70°F) at start up.
* The ECT is greater than 70°C (158°F).
* The ECT is greater than 55°C (131°F) at start up.
* The vehicle speed is greater than 8 km/h (5 mph) for 300 seconds.
* The vehicle speed is less than 200 km/h (124 mph) for 5 seconds.
* The TCM temperature parameter is -49 to +169°C (-56 to +336°F).
P0712
DTC P0712 is not failed this ignition cycle.
P0713
DTC P0713 is not failed this ignition cycle.
Conditions for Setting the DTC
P0711 - Fail Case 1
* Vehicle speed is greater than 8 km/h (5 mph) for 300 seconds cumulative.
* The Trans. Fluid Temp. parameter is between -50 and +21°C (-58 and +70°F).
* The Trans. Fluid Temp. parameter has changes by less than 2.0°C (3.6°F) in 100 seconds.
* The engine coolant temperature (ECT) is greater than 70°C (158°F).
* The ECT has increased by 55°C (99°F) since startup.
P0711 - Fail Case 2
* The Trans. Fluid Temp. parameter is between 129-170°C (264-338°F).
* The Trans. Fluid Temp. parameter has changed by less than 2.0°C (3.6°F) in 100 seconds.
* The ECT is greater than 70°C (158°F).
* The ECT has increased by 55°C (99°F) since startup.
P0711 - Fail Case 3
The Trans. Fluid Temp. parameter changes by greater than or equal to 20°C (36°F) 5 times over 7 seconds.
P0711 - Fail Case 4
* The Trans. Fluid Temp. parameter start up temperature is -50°C (-58°F) and does not reach +20°C (+68°F) within 3200 seconds.
* The Trans. Fluid Temp. parameter start up temperature is -25°C (-13°F) and does not reach +20°C (+68°F) within 2600 seconds.
* The Trans. Fluid Temp. parameter start up temperature is -10°C (-14°F) and does not reach +20°C (+68°F) within 2000 seconds.
* The Trans. Fluid Temp. parameter start up temperature is -5°C (-23°F) and does not reach +20°C (+68°F) within 1800 seconds.
* The Trans. Fluid Temp. parameter start up temperature is 20°C (68°F) and does not reach +20°C (+68°F) within 300 seconds.
P0712
The Trans. Fluid Temp. parameter is greater than or equal to 160°C (320°F) for greater than 25 seconds.
P0713
The Trans. Fluid Temp. parameter is less than or equal to -60°C (-76°F) for greater than 10 seconds.
Action Taken When the DTC Sets
* P0711 is a Type A DTC.
* P0712 and P0713 are Type B DTCs.
* The transmission control module freezes transmission adaptive functions.
Conditions for Clearing the DTC
* P0711 is a Type A DTC.
* P0712 and P0713 are Type B DTCs.
Diagnostic Aids
The driver information center, if equipped, will display 'TRANSMISSION HOT - Idle Engine' when the Trans. Fluid Temp. parameter reaches 132°C (270°F). The Trans. Fluid Temp. parameter on the scan tool should rise steadily to a normal operating temperature, and then stabilize. Ask about the customer's driving habits, trailer towing, overloading, etc. Ensure the engine and transmission cooling system is functioning normally.
Reference Information
Schematic Reference
Automatic Transmission Controls Schematics (Diagrams)
Connector End View Reference
Component Connector End Views (Connector Views)
Electrical Information Reference
* Circuit Testing (Circuit Testing)
* Connector Repairs (Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (Wiring Repairs)
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions (Powertrain Diagnostic Trouble Code (DTC) Type Definitions)
Special Tools
J 24731 Tempil Stick
Circuit/System Verification
Ignition ON, observe the scan tool Trans. Fluid Temp. and the TCM temperature parameters. The readings should vary less than 10°C (18°F).
If within the specified range, test for a transmission overheat condition.
If greater than the specified range, replace the Q8 control solenoid valve assembly.
Component Testing
* Perform the Fluid Leak Diagnosis (Fluid Leak Diagnosis).
* Perform the Transmission Fluid Level and Condition Check (Transmission Fluid Level and Condition Check) procedure.
* Perform the Line Pressure Check (Line Pressure Check) procedure.
* Perform the Main Fluid Pump Pressure High or Low (Main Fluid Pump Pressure High or Low) procedure.
* With a hand held infra red thermometer, or J 24731 test for the transmission cooler supply line thermostat for opening at 80°C (176°F). The transmission cooler supply line temperature should be higher on the transmission side of the thermostat than the cooler side until 80°C (176°F) is reached.
• If the thermostat tests stuck open or closed, replace the transmission cooler supply pipe assembly.
Perform the Control Solenoid Valve and Transmission Control Module Assembly Inspection (Control Solenoid Valve and Transmission Control Module Assembly Inspection).
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
* Transmission Fluid Cooler Pipe Replacement (Service and Repair)
* Control Module References (Programming and Relearning) for Q8 control solenoid valve assembly replacement, setup, and programming.