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DD-520196-1 moderate Detroit Diesel DD Series ›

Coolant Deaeration Problem

My Garage →
Can I Drive?
Yes, But Fix Soon
DIY Difficulty
intermediate
Estimated Cost
$500-$2,200

What does DD-520196-1 mean?

The DD-520196-1 (Detroit Diesel DD Series) diesel fault code means: Coolant Deaeration Problem. This is a moderate severity code.

Common Symptoms

  • Check Engine Light / Amber Warning Lamp illuminated
  • Coolant loss without leak

Probable Causes (Ranked by Likelihood)

  • Air in coolant system Likely
  • Head gasket weep Possible

Step-by-Step Diagnostic Procedure

  1. Bleed coolant system at high points.

  2. Combustion leak test on surge tank.

Frequently Asked Questions

What is Detroit Diesel fault code DD-520196-1?

Detroit Diesel fault DD-520196-1 (SPN 520196 FMI 1) indicates: Coolant Deaeration Problem. It is a moderate-severity fault and is commonly seen on DD13/DD15/DD16 engines in Freightliner and Western Star chassis.

Can I drive my Freightliner or Western Star with fault DD-520196-1?

It depends on severity. Critical and serious faults trigger derate or engine shutdown — do not continue driving. Moderate faults usually allow continued operation short-term but schedule repair to prevent cascading aftertreatment damage.

How much does it cost to fix Detroit Diesel fault DD-520196-1?

Typical repair cost is $500-$2,200. Sensor/harness fixes fall at the low end; turbo actuator, injector, aftertreatment component, or head gasket repairs fall at the high end. Detroit DDDL software and sometimes factory parameter reset are required for proper reset.

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