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| • | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
| • | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
| • | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
TFT Sensor Signal | P0712 | P0713 | P0713 | P0711 |
Low Reference | -- | P0713 | - | P0711 |
Circuit | Short to Ground | Open/High Resistance | Short to Voltage |
|---|---|---|---|
Operating Conditions: Engine running in Park, normal operating temperature Parameter Normal Range: -39 to +149°C (-38 to +300°F) | |||
TFT Signal | Greater than 149°C (300°F) | Less than -39°C (-38°F) | Less than -39°C (-38°F)* |
Low Reference | -- | Less than -39°C (-38°F) | Less than -39°C (-38°F)* |
* Internal TFT sensor damage may result if shorted to B+ | |||
The primary sources of heat in the transmission are 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 transmission cooler, which is internal to 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 part of the control solenoid valve assembly and is not serviced separately.
| • | No OSS DTCs P0721, P0722, or P0723, P077B, P215C. |
| • | The ignition 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 TCM temperature parameter is -49 to +169°C (-56 to +336°F).
DTC P0712 is not failed this ignition cycle.
DTC P0713 is not failed this ignition cycle.
| • | The difference between the TCM temperature and Trans. Fluid Temp. is greater than 15-50°C (59-122°F), depending on the highest of the Trans. Fluid Temp., TCM temperature and TCM power-up temperatures. |
| • | The difference between the TCM power-up temperature and TCM substrate temperature is greater than 15-50°C (59-122°F), depending on the highest of the Trans. Fluid Temp., TCM temperature and TCM power-up temperatures. |
| • | The above conditions have to be met for 5 minutes. |
The Transmission Fluid Temperature parameter is less than or equal to -60°C (-76°F) for greater than 60 seconds.
The Transmission Fluid Temperature parameter is greater than or equal to 160°C (320°F) for greater than 60 seconds.
| • | DTC P0711 is a Type B DTC. |
| • | DTCs P0712 and P0713 are Type A DTCs. |
| • | DTC P0711 is a Type B DTC. |
| • | DTCs P0712 and P0713 are Type A DTCs. |
The Transmission Fluid Temperature parameter on the scan tool should rise steadily to a normal operating temperature, and then stabilise. Ask about the customer's driving habits, overloading, etc. Ensure the engine and transmission cooling system is functioning normally.
Automatic Transmission Controls Schematics
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
GE 24731 Tempil Stick
Vehicle ON, observe the scan tool Transmission Fluid Temperature and the TCM temperature parameters. The readings should vary less than 30°C (86°F).
| ⇒ | If within the specified range, test for a transmission overheat condition. Refer to Automatic Transmission Overheating . |
| ⇒ | If greater than the specified range, replace the Q8 control solenoid valve assembly. |
| • | Perform the Fluid Leak Diagnosis . |
| • | Perform the Transmission Fluid Level and Condition Check procedure. |
| • | Perform the Line Pressure Check procedure. |
| • | Perform the Main Fluid Pump Pressure High or Low procedure. |
| • | With a hand held infra red thermometer, or GE 24731 tempil stick 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 test indicates that the thermostat is stuck open or closed, replace the transmission cooler supply pipe assembly. |
Perform the Control Solenoid Valve and Transmission Control Module Assembly Inspection .
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for Control Solenoid Valve Assembly and Transmission Control Module Assembly replacement, programming, and setup. |
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