Coolant Temperature High-Moderate
The DD-110-16 (Detroit Diesel DD Series) diesel fault code means: Coolant Temperature High-Moderate. This is a moderate severity code.
This is a standard J1939 fault, not a proprietary code. DD-110-16 is how this equipment displays SPN 110 with FMI 16 (data valid but above normal — moderately severe) under the SAE J1939 standard used across heavy equipment. The same SPN can appear on any J1939-compliant machine regardless of brand — so cross-referencing it against your engine maker's documentation is valid even when the equipment brand differs.
- Keep driving?
- Yes, but fix soon
- DIY difficulty
- intermediate
- Estimated cost
- $500-$2,200
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What Are the Symptoms of DD-110-16?
- Check Engine Light / Amber Warning Lamp illuminated
- Gradual overheat trend
What Causes DD-110-16? (Most Likely First)
- Partial head gasket breach Likely
- Soft thermostat Likely
- Aging water pump Possible
Can I Still Drive with DD-110-16?
Yes, but fix soon. DD-110-16 is rated moderate severity. It is not an immediate stop-driving fault, but it will not clear itself — book the repair rather than ignoring it.
Frequently Asked Questions
What is Detroit Diesel fault code DD-110-16?
Detroit Diesel fault DD-110-16 (SPN 110 FMI 16) indicates: Coolant Temperature High-Moderate. 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-110-16?
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-110-16?
Estimated 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.
Mechanics Guide Step-by-step diagnosis
How Do You Diagnose DD-110-16?
Use a combustion leak tester on the coolant surge tank.
Pressure-test cooling system; watch for bubbles at refill cap.
Replace thermostat first if borderline.
Sources 2
This page is built from documented references. Verify against your own service info before repair work.
- John Deere Operator's Manual, PowerTech 4.5 L and 6.8 L Tier 2 OEM Diesel Engines, OMRG33324 (Issue 16Feb04), reproduced as a supplement in Genie's telehandler parts library (doc 237949), "Listing of Diagnostic Trouble Codes"printed page 45-24: SPN 110 FMI 16, "Engine Coolant Temperature High Moderately Severe". The table is that engine maker's; it establishes what the J1939 SPN-FMI pair means, not that a Detroit Diesel display shows it.
- Perkins 854F-34T Engine Fault Code table, printed in the Genie S-100/S-105/S-120/S-125 Service Manual, Part No. 102916, January 2016printed page 5-29: SPN 110 FMI 16, "Engine Coolant Temperature: High - moderate severity (2)". The table is that engine maker's; it establishes what the J1939 SPN-FMI pair means, not that a Detroit Diesel display shows it.
Which Vehicles Commonly Get DD-110-16?
- Freightliner Cascadia with DD15
- Freightliner Cascadia with DD13
- Freightliner Cascadia with DD16
- Western Star 4700 with DD13/DD15
- Western Star 4900 with DD15/DD16
- Western Star 5700 XE with DD15
- Freightliner M2 106 with DD13
- Freightliner M2 112 with DD13
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