Circuit Description
Transmission fluid life is determined by monitoring transmission fluid temperature over a period of time. The transmission control module (TCM) calculates transmission fluid life based on a set of temperature ranges stored in TCM memory. As the vehicle is driven, a counter increments. The rate at which the counter increments depends on the temperature range in which the transmission is currently operating in. The higher the temperature range, the faster the counter increments. As the counts increment, the TCM will begin to decrease the fluid life percentage from 100, high fluid life, to 0, low fluid life.
If the TCM detects a calculated transmission oil life of 10 percent or less, then DTC P0897 sets. DTC P0897 is a type C DTC.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC P0897 Transmission Fluid Life
Conditions for Running the DTC
No TFT DTCs P0711, P0712, or P0713.
Conditions for Setting the DTC
The calculated transmission oil life remaining is 10 percent or less.
Action Taken When the DTC Sets
| • | The TCM does not request the engine control module (ECM) to illuminate the malfunction indicator lamp (MIL). |
| • | CHANGE TRANSMISSION FLUID displays on the driver information center (DIC). |
| • | The TCM records the operating conditions when the Conditions for Setting the DTC are met. The TCM stores this information as Failure Records. |
| • | The TCM stores DTC P0897 in TCM history. |
Conditions for Clearing the DIC/DTC
| • | The TCM clears the DIC when the condition no longer exits. |
| • | A scan tool can clear the DIC/DTC. |
| • | The TCM clears the DTC from TCM history if the vehicle completes 40 warm-up cycles without a non-emission-related diagnostic fault occurring. |
| • | The TCM cancels the DTC default actions when the fault no longer exists and the DTC passes. |
Diagnostic Aids
Inspect the transmission cooling system for possible blockage and restrictions.
Test Description
The numbers below refer to the step numbers on the diagnostic table.
Step | Action | Values | Yes | No |
|---|---|---|---|---|
1 | Did you perform the Diagnostic System Check - Vehicle? | -- | Go to Step 2 | |
Important: Before clearing the DTC, use the scan tool in order to record the Failure Records. Using the Clear Info function erases the Failure Records from the TCM. Refer to Auxiliary Control Valve Body Cover, Fluid Filter Seal, and Filter Removal in the 4T80-E section of the Transmission Unit Repair Manual. Did you complete the above procedures? | -- | Go to Step 3 | -- | |
3 | Perform the following procedure in order to verify the repair:
Has the test run and passed? | -- | Go to Step 4 | Go to Step 2 |
4 | With the scan tool, observe the stored information, capture info. and DTC info. Does the scan tool display any DTCs that you have not diagnosed? | -- | System OK |
