DEF Inducement DEF Lamp Active

SPN 521049/FMI 31

Description This Code Sets When There is a Code Present for the Diesel Exhaust Fluid (DEF) Tank Level, DEF Dosing Unit, DEF Pump, NOx Sensors, Blocked DEF Line, DEF Quality, NOx Efficiency, Selective Catalyst Reduction (SCR) Harness and/or SCR Sensor.
Monitored Parameter SCR and Diesel Particulate Filter (DPF) Sensors
Typical Enabling Conditions Always Enabled
Monitor Sequence None
Execution Frequency Always Enabled
Typical Duration Two Seconds
Dash Lamps DEF Lamp
Engine Reaction 25% Derate
Verification High Idle Regeneration followed by a Parked SCR Efficiency Test

Check as follows:

Show/Hide Checkboxes
1. Connect DiagnosticLink®

2. Turn the ignition ON (key ON, engine OFF).

During parked regeneration the exhaust gases will be extremely HOT and could cause a fire if directed at combustible materials. The vehicle must be parked outside.

3. Check for other emission-related fault codes. Are there any Selective Catalyst Reduction (SCR) or Diesel Particulate Filter (DPF) related fault codes present?1. Yes; diagnose and repair the emission-related fault codes first. Verify repair.

2. No; perform a high idle regeneration. When the engine returns to idle, turn the ignition OFF and wait for all the modules to power down (usually about one minute). Turn the ignition ON (key ON, engine OFF) and wait one minute, then start the engine and run a Parked SCR efficiency test. Use DiagnosticLink to clear the code.