P1797
P1797-MANUAL SHIFT OVERHEATFor a complete wiring diagram, refer to: Electrical Diagrams
When Monitored
Continuously with engine running.
Set Condition
If the Engine Temperature exceeds 123°C (255°F) or the Transmission Temperature exceeds 1350 C (2750 F) while in AutoStick mode. Note: Aggressive driving or driving in low for extended periods of time will set this DTC.
Possible Causes
- MANUAL SHIFT OVERHEAT
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding.
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 mode, internal controller logic prevents the transmission from overheating by managing the shift and EMCC schedule. In the autostick mode, when the transmission or engine temperature approaches an overheat condition, the manual shift overheat DTC sets and the autostick mode is temporarily suspended until the temperature returns to normal.
Diagnostic Test
1. MANUAL SHIFT OVERHEAT
This is an informational DTC only.
With the scan tool, check the EATX 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 per the Service Information 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 per the Service Information. Refer to Service Information for the related symptoms and repair as necessary.
Perform 42RLE TRANSMISSION VERIFICATION TEST - Ver 1. Verification Tests.