C13, C15, and C18 Engines Troubleshooting – Idle Speed Is High

Table 1
Diagnostic Trouble Codes
CDL Code J1939 Code Description
(Code descriptions may vary)
E441 (1) Idle Elevated to Increase Battery Voltage The battery voltage is below 24.5 VDC for 5 minutes.
The engine speed is increased to 1000 rpm. The code is logged.

Probable Causes


  • Charging circuit 
  • Low battery engine elevated idle 

Recommended Actions

Table 2
Troubleshooting Test Steps Values Results
1. Charging Circuit

A. Inspect the battery and charging circuit. Refer to Systems Operation/Testing and Adjusting, “Electrical System” for additional information.

Charging circuit Result: The charging circuit is operating properly.

Proceed to Test Step 2.

Result: The charging circuit is not operating properly.

Repair the charging system. Verify the repair.

2. Low Battery Engine Elevated Idle

A. This condition is normal operation. The engine idle speed will be elevated to 1000 rpm when all of the following conditions occur:

1. Low Battery Engine Elevated Idle is enabled.
2. A valid throttle position is present. The throttle position has not exceeded 25 percent of full throttle for 5 minutes.
3. The transmission is in neutral.
4. The parking brake is engaged.
5. A valid engine speed is present.
6. System battery voltage is below 24.5 VDC for 5 minutes.

Normal operation Result: This condition is normal operation.

Return the unit to service.

Complete the procedure in the order in which the steps are listed.

If the procedure did not correct the issue, contact your Cat dealer Technical Communicator (TC). For further assistance, your TC can confer with the Dealer Solutions Network (DSN).


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