DEF Dosing Inducement Category Code (Originates From Another DTC)

Common Symptoms

• DEF / SCR warning lamp and derate countdown
• SCR inducement active (speed limit, eventual no-restart)
• White crystal (urea) deposits near the DEF doser
• Poor fuel economy / elevated NOx
• DEF dosing reported low or not responding on the scan tool

Probable Causes (Ranked by Likelihood)

• Crystallized or clogged DEF doser/injector tip (DEF won't atomize) Likely
• DEF pump cannot build or hold commanded pressure Likely
• Contaminated or out-of-spec DEF (diesel, water, or aged fluid) Possible
• Restricted DEF supply line or failed line heater (frozen lines) Possible
• Doser wiring or connector fault Possible

Step-by-Step Diagnostic Procedure

1. P1514 is a DEFOI category / inducement code -- start by reading ALL stored SCR, NOx, and DEF-dosing DTCs with DAVIE4 or PACCAR ESA. Per PACCAR guidance, do not replace parts on P1514 alone; identify and repair the underlying active DEF-dosing fault that set it (P1514 clears once that originating code is resolved).

2. Remove and inspect the DEF doser for crystallization; clean with warm distilled water and reinstall.

3. Check DEF concentration with a refractometer (should be 32.5% urea). Replace contaminated or out-of-spec fluid.

4. Inspect DEF supply lines for restriction and verify the line heaters work in cold weather.

5. Check the doser connector and wiring for corrosion or damage.

6. Read all stored SCR/NOx codes together -- P1514 commonly appears alongside other aftertreatment faults, so address the whole SCR picture rather than this code in isolation.

Frequently Asked Questions