Troubleshooting guide

CODES

Logic codes identify a condition NOT a component.

Example: Code 39 DDEC uses the Differential Pressure sensor and EGR temperature sensor to

monitor EGR flow.

If flow is detected when there should be no flow, code 39 will activate.

If NO FLOW is detected when there should be flow, code 39 will activate.

Conditions that can cause Code 39 include but are not limited to:

Plugged EGR cooler

EGR valve defective (stuck open or closed)

VPOD defective

Differential pressure sensor plugged

The DTC will help guide the technician to the condition. The technician will require a knowledge

of the system and proper tools to diagnose the components.

4-2 All information subject to change without notice. (Rev. April 2004)