P1797

P1797-MANUAL SHIFT OVERHEAT

For a complete wiring diagram refer to Diagrams/Electrical. Electrical Diagrams


Theory of Operation


The major cause of heat build up in the transmission is torque converter slip. With the transmission in the AutoStick(R) mode, the torque converter can slip during aggressive driving or heavy loading conditions such as trailer towing or driving up steep grades. In the non AutoStick(R) mode, internal controller logic prevents the transmission from overheating by managing the shift and EMCC schedule. In the AutoStick(R) mode, when the transmission or engine temperature approaches an overheat condition, the manual shift overheat DTC sets and the AutoStick(R) mode is temporarily suspended until the temperature returns to normal.


- When Monitored:

Continuously with engine running.

- Set Condition:

If the Engine Temperature exceeds 123� C (255� F) or the Transmission Temperature exceeds 135� C (275� F) while in AutoStick(R) mode. Note: Aggressive driving or driving in Low for extended periods of time will set this DTC.







Always perform the 42RLE Pre-Diagnostic Troubleshooting procedure before proceeding. 42RLE - Pre-Diagnostic Troubleshooting Procedure



Diagnostic Test


1. MANUAL SHIFT OVERHEAT

This is an informational DTC only.

With the scan tool, check the DTC EVENT DATA to help identify the conditions in which the DTC was set.

Check the engine and transmission cooling system for proper operation.

Check the Radiator Cooling Fan operation.

Check the Transmission Cooling operation.

Check the Transmission Fluid Level to verify that it is not overfilled.


NOTE: Aggressive driving or driving in Low for extended periods of time will set this DTC.

If there are no possible causes remaining, view repair.

Repair

- If the Transmission Fluid is low, repair any Transmission Fluid leak as necessary and adjust the Transmission Fluid Level.
- Perform 42RLE TRANSMISSION VERIFICATION TEST. 42RLE Transmission Verification Test