COUPLING 4783809 - Caterpillar

Petroleum Transmissions are equipped with a feature which stalls the torque converter to warm the transmission and engine in cold environments. Stalling the torque converter increases load on the engine and generates heat in the torque converter. The heated torque converter oil transfers heat to the engine coolant through the transmission oil cooler. Also, heat transfers to the sump oil after the oil returns to the transmission.For applications using a J1939 shifter, this feature may be initiated by shifting to "2R". For applications using a switch to ground type shifter, this feature is initiated by shifting to Park. The switch will ground the Stall Enable circuit of the transmission or connect ECM pin J1-64 (customer connector pin 40) to ground. The Transmission ECM will engage stall when all of the following conditions are met:
The transmission oil temperature is less than 87° C (189° F)
The torque converter oil temperature is less than 110° C (230° F)
Engine speed is less than 1000 rpm and greater than 500 rpmThe transmission will automatically shift from Stall to Park when any of the following occur:
If transmission oil temperature exceeds 93° C (200° F)
If torque converter oil temperature exceeds 120° C (248° F)
Engine speed exceeds 1300 rpm.A “Transmission Abuse Warning Event” will be logged if the engine speed exceeds 1000 rpm while the transmission is in park. When stall mode is selected, the transmission will automatically cycle between Stall and Park according to the above criteria. The maximum rate of cycling into Stall is limited to once every 60 seconds by a timer. When the transmission oil cools or the speed drops, the converter stall mode for transmission warm-up will automatically engage once the criteria are met.The following active electrical faults will disable Stall forcing the transmission to shift to Park instead.
Active ECPC solenoid diagnostic fault
Active lock up clutch solenoid short to battery diagnostic fault
Torque converter oil temperature sensor faults
Engine speed sensor faultsIf the transmission output speed exceeds 50 rpm while in stall mode, the transmission will do the following:
Shift to Park
Record a 718-14 transmission system special instruction diagnostic code in Cat Electronic Technician.
Light the amber warning lamp and broadcast the amber warning lamp status on J1939 DM2 (Diagnostic Message 2)