HOUSING AS 9U2400 - Caterpillar

Probable Causes
Programmable parameters
Engine retarder switches
Accelerator pedal position sensor
Clutch switch
PTO on/off switchRecommended Actions
Check the Programmable Parameters
Use the Caterpillar Electronic Technician (ET) to check the following parameters while the engine is not running:Engine Retarder Mode - If the engine retarder mode is programmed to "Latch" or to "Coast", the engine retarder will not activate unless the service brake pedal is depressed. If the engine retarder mode is programmed to "Manual", service brakes are not required to activate the engine retarder."Engine Retarder Minimum Vehicle Speed" - The engine retarder will not turn on below the value that is programmed for this parameter."Engine Retarder Minimum Vehicle Speed Type" - When vehicle speed drops below the "Engine Retarder Minimum Vehicle Speed" and this parameter is programmed to "Hard Limit" the engine retarder turns off. When vehicle speed drops below the "Engine Retarder Minimum Vehicle Speed" and this parameter is programmed to "Soft Limit" the engine retarder remains on."Engine Retarder Delay" - This parameter provides a programmable delay after the conditions that turn on the engine retarder are met.Refer to Troubleshooting, "Configuration Parameters" for additional information on these parameters.Check the Engine Retarder Switches
Note: Some vehicles may have a set of engine retarder switches on the dash and on the shift lever. Check both sets of switches, if necessary.Turn the on/off switch for the engine retarder to the ON position.Use Cat ET to monitor the status of the engine retarder switches while the switches are moved to the following positions:
Off
Low
Medium
HighIf the status of the switches does not correspond to the position of the switches, refer to the circuit test Troubleshooting, "Retarder - Test".Check the Accelerator Pedal Position Sensor
Use Cat ET to monitor the status of the accelerator pedal position.Monitor the status of the accelerator pedal position while you operate the pedal. Depress the pedal and release the pedal several times.The status of the accelerator pedal position should vary between 3 percent and 100 percent. If the accelerator pedal position does not vary between 3 percent and 100 percent, refer to the circuit test Troubleshooting, "Sensor Signal (PWM) - Test".Check the Clutch Switch
Use Cat ET to monitor the status of the clutch switch.Monitor the status of the clutch switch while you operate the clutch pedal. Depress the pedal and release the pedal several times.The status of the clutch switch should indicate that the clutch pedal is being depressed and released. When the clutch pedal is depressed the status should indicate ON. When the clutch pedal is released the status should indicate OFF. If the status of the clutch switch does not correspond to the position of the clutch pedal, refer to the circuit test Troubleshooting, "Speed Control (Auxiliary) - Test".Check the PTO On/Off Switch
Note: If the "PTO Configuration" is programmed to "Cab Switches", to "Remote", to "Switches", or to "Remote Throttle" the engine retarder is disabled when the PTO is ON.Use Cat ET to monitor the status