HARNESS AS-SENSOR 5253740 - Caterpillar

Table 1
Engine Events
J1939 Code and Description Conditions which Generate the Code System Response
4779-0 Aftertreatment #1 Three Way Catalyst Differential Gas Temperature : High - most severe (3) The differential temperature across the catalytic converter is above the trip point for the programmed delay time. The code is logged.
The red stop lamp is illuminated.
The engine is shut down.
4779-15 Aftertreatment #1 Three Way Catalyst Differential Gas Temperature : High - least severe (1) The code is logged.
The amber warning lamp is illuminated. Probable Causes
Incorrect engine timing
Engine misfireRecommended Actions
Incorrect Engine Timing
Engine timing that is excessively retarded can affect exhaust temperatures and coolant temperatures.The ignition timing for this engine is automatically calibrated during engine startup. If a problem with the timing calibration is suspected, refer to Troubleshooting, "Speed/Timing - Test" for additional information.Verify that the timing is programmed correctly. Refer to Systems Operation, "System Configuration Parameters" for Information that is related to setting the timing parameters.Engine Misfire
An engine misfire allows unburned gas into the exhaust system. The excess gas can be burned in the inlet of the catalytic converter. High exhaust temperature at the inlet of the catalytic converter will result.Check the engine for a misfire condition. Refer to Troubleshooting, "Engine Misfires, Runs Rough or Is Unstable" for details.