C175-16 Locomotive Engine Caterpillar

Manifold DEF Temperature Is High

Usage:

Use this procedure to troubleshoot an engine with high manifold DEF temperature. Also, use this procedure if one of the following event codes is active or logged.

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Table 1
J1939 Code and Description	CDL Code and Description	Comments
4337-15 Aftertreatment #1 DEF Doser #1 Temperature : High - least severe (1)	E934(1) High Aftertreatment #1 DEF Temperature #1	The DEF manifold temperature is too high.

Probable Causes

Code
DEF manifold heater
Sensor

Recommended Actions

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Table 2
Troubleshooting Test Steps	Values	Results
1. Check for Codes A. Apply electrical power to the engine. B. Connect Cat^® Electronic Technician (ET) to the service tool connector. C. Look for active codes that are associated with the system for the event code.	Codes	Result: An associated code is present. Repair: Troubleshoot any associated codes before continuing with this test. Result: A 4337-15 code is present. Proceed to Test Step 2.
2. Check the DEF Manifold Heater A. Remove electrical power from the engine. B. Disconnect the DEF manifold heater from the wiring harness connector. C. Apply electrical power to the engine. D. Measure the voltage on the DEF manifold heater wiring harness connector.	24 VDC	Result: There was NOT 24 VDC at the DEF tank manifold connector. Proceed to Test Step 3. Return to service. Result: There was 24 VDC at the DEF tank manifold connector. Repair: Replace the DEF manifold heater relay.
3. Check the DEF Manifold Temperature Sensor A. Apply electrical power to the engine. B. Connect Cat ET. C. Monitor the "DEF Dosing Reagent Temperature" D. The "DEF Dosing Reagent Temperature"should be within 5° C (9° F) of ambient temperature.	DEF Manifold Temperature	Result: The "DEF Dosing Reagent Temperature" is within 5° C (9° F) of ambient temperature. Verify that the repair eliminated the problem. Result: The "DEF Dosing Reagent Temperature" is greater 5° C (9° F) of ambient temperature. Repair: Replace the DEF manifold temperature sensor. Verify that the repair eliminated the problem.

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).