RETAINER 7G7736 - Caterpillar

Use this procedure in order to troubleshoot an occurrence for an engine overspeed or use this procedure if the following diagnostic code is active. Refer to Troubleshooting, "Engine Monitoring Parameters" for information about engine events. Access the engine monitoring system on Caterpillar Electronic Technician (ET) in order to view the current trip points for these codes. For information on the engine monitoring system, refer to Troubleshooting, "Engine Monitoring System".
Table 1
Engine Events
J1939 Code and Description Conditions which Activate this Code System Response
190-0 Engine Speed : High - most severe (3) The engine rpm has exceeded the trip point for an engine overspeed. The code is logged.
The red stop lamp is illuminated.
The gas shutoff valve is de-energized.
The ignition is shut off.
The engine is shut down.
190-15 Engine Speed : High - least severe (3)
(for CG-137 applications only) The engine rpm has exceeded the trip point for an engine overspeed. The code is logged.
The red stop lamp is illuminated.
The gas shutoff valve is de-energized.
The ignition is shut off.
The engine is shut down.
Unburned gas in the air inlet and exhaust system may ignite when the engine is started. Personal injury and/or property damage may result.Before starting an engine that may contain unburned gas, purge the unburned gas from the air inlet and exhaust system. Refer to the topic on purging unburned gas in the "Starting the Engine" section.
Probable Causes
Driven equipment
Sudden drop of load
Governor adjustment
Throttle actuator
Uncontrolled fuel supplyRecommended Actions
Driven Equipment
Determine if the driven equipment has additional inputs of energy that could drive the engine beyond the trip point for an engine overspeed. Initiate corrective measures to the installation in order to prevent the overspeed from recurring.Sudden Drop of Load
Decrease the load on the engine gradually.Governor Adjustment
The governor parameters must be programmed with the values that provide stable operation without an engine overspeed. Refer to Testing and Adjusting, "Engine Governing - Adjust".Throttle Actuator
Set the engine control to the OFF position. Remove the electrical power from the engine. Move the throttle plate through the entire range of travel while you feel the motion. If the motion is sticky and/or rough, investigate the cause of the binding. Perform the necessary repairs.Uncontrolled Fuel Supply
A gas engine can overspeed if fuel that is uncontrolled is drawn into the air inlet system. This problem can occur when a gas leak occurs in the surrounding environment. This problem is more probable for applications that are for gas compression. If uncontrolled fuel is drawn into the air inlet, the Electronic Control Module (ECM) may not be able to prevent an engine overspeed.