Diesel Trouble Codes

DTC 114 — Engine Coolant Temperature Signal Out of Range – Low — International DT466E

DTC 114 on International DT466E (1996–2003) indicates the ECM sees an ECT sensor signal voltage below its valid range. The code is a Navistar three-digit flash…

Updated October 15, 2026

What it means

On the DT466E, DTC 114 means the engine coolant temperature (ECT) sensor signal voltage is below its valid range. The code is a Navistar three-digit diagnostic trouble code read by flash codes or a scan tool. Typical on this platform is a shorted ECT sensor or a signal wire shorted to ground.1

Most likely causes

  1. ECT sensor internally shorted, pulling signal voltage low — A shorted coolant temperature sensor can hold the signal line near ground, causing the ECM to read an out-of-range low voltage.1
  2. ECT signal wire shorted to chassis ground or harness chafing — Physical damage or chafing of the ECT wiring can short the signal conductor to ground, producing a low-voltage reading at the ECM.1
  3. Corroded or loose ECT connector causing intermittent low bias — Poor terminal contact at the sensor connector can introduce resistance or a ground path that biases the signal low.1
  4. ECM reference voltage or ground issue affecting the ECT circuit — A low ECM supply or a compromised sensor ground can make the ECT signal appear low even if the sensor and wiring are intact.1

How to diagnose

  1. Verify the code with a Navistar-compatible scan tool or flash code read and confirm DTC 114 is present and active.
  2. Inspect the ECT sensor connector for corrosion, moisture, bent pins, and secure seating; repair or clean as needed.
  3. Visually inspect the ECT wiring harness from the sensor to the ECM for chafing, melted insulation, or contact with hot/exhaust components that could short the signal to ground.
  4. With key on, engine off, check ECM supply voltage and sensor ground integrity; low system voltage can affect sensor readings.
  5. Disconnect the ECT sensor and measure sensor resistance across its terminals at known temperature; compare to the DT466E ECT resistance/temperature chart. A shorted sensor reads near zero ohms.
  6. With the sensor disconnected and key on, measure signal voltage at the harness side; an abnormally low voltage indicates a short to ground in the harness or ECM issue.
  7. If the sensor and wiring test normal, monitor live ECT data while gently wiggling the harness to reveal intermittent shorts to ground.

Parts and tools you may need

Tools you’ll need

Rough cost and difficulty

Likely repairPartsShop laborWho usually does it
Wiring or connector repair$10–$1001–4 hrsDIY with tools and a manual
Temperature or pressure sensor (coolant, intake air, oil, fuel temp)$30–$1500.3–1.5 hrsEasy DIY
ECM/PCM replacement (programmed)$600–$2,0001–3 hrsShop

Typical US independent-shop figures; labor runs about $140–$200 per hour (dealers charge more). Confirm the diagnosis before buying parts.

When to see a pro

If the harness tests good and a known-good ECT sensor does not clear DTC 114, have a qualified diesel technician evaluate the ECM and wiring integrity. Do not attempt high-pressure oil system service for this code.

Check for recalls

Recalls are tied to your truck’s VIN, so check yours directly: enter the VIN at NHTSA’s recall lookup. Open safety recalls are repaired free at a dealer.

Sources

  1. Curated DTC seed — International DT466E (curated) ↩︎ ↩︎ ↩︎ ↩︎ ↩︎