P0897

P0897 - Transmission Fluid Deteriorated

For a complete wiring diagram, refer to.

Theory of Operation

To prevent a bump due to A/C clutch engagement, a temporary torque converter partial EMCC condition is established prior to A/C clutch engagement. A message is received over the bus indicating that A/C clutch engagement is imminent. Partial EMCC is then established and a reply message, "OK to engage A/C clutch" is sent via the bus. Partial EMCC will be held for 450 ms before returning to full EMCC. During the transition from full to partial EMCC, a turbine acceleration sum is calculated, if this value exceeds a threshold value for several transitions, degraded transmission fluid is indicated.

• When Monitored: Each transition from full EMCC to partial EMCC for A/C bump prevention.

• Set Condition: DTC set if 20 occurrences of a turbine acceleration sum. Fault Set Time: 20 transitions from full EMCC to partial EMCC. Transmission will not use partial EMCC. Established for A/C bump prevention.






Always perform the pre-diagnostic troubleshooting procedure before proceeding. Refer to => Non-DTC Based Diagnostics. Pre-Diagnostic Troubleshooting Procedure

Test Step 1 - Worn Out / Burnt Transmission Fluid

• Turn the ignition OFF to the lock position.

• Flush the transmission oil cooler and lines, replace the transmission oil filter, refill with new transmission fluid, start the engine, and adjust the fluid.

• The transmission cooler must be flushed before proceeding.

• Allow the engine to idle for 10 minutes, in Park.

• Turn the ignition OFF to the lock position.

• Again, flush the transmission oil cooler and lines, replace the transmission oil filter, refill with new transmission fluid, start the engine, and adjust the fluid.

• With the scan tool, perform a battery disconnect.

• The battery disconnect must be done to re-enable EMCC during an A/C clutch engagement.

• The vehicle may exhibit intermittent shudder during the first few hundred miles. The new transmission fluid will gradually penetrate the torque converter clutch friction material and the shudder should disappear.

• Erase the DTC and return the vehicle to the customer.

Did the DTC reset and/or does the vehicle still shudder after a few hundred miles?

Yes

• Replace the torque converter.

• Perform the Transmission Verification Test. Refer to => Non-DTC Based Diagnostics. Transmission Verification Test

No

• Test Complete.