SPN 110 - FMI 2 (Fault Code 334)

SPN 110 - FMI 2 (Fault Code: 334)
Engine Coolant Temperature Sensor

Fault Code: 334
PID(P), SID(S): P110
SPN: 110
FMI: 2

REASON: Engine Coolant Temperature - Data Erratic, Intermittent, or Incorrect. The engine coolant
temperature reading is NOT changing with engine operating conditions.

EFFECT: The ECM will estimate engine coolant temperature.

Circuit Description:
The engine coolant temperature sensor is used by the electronic control module (ECM) to monitor the engine coolant temperature. The ECM monitors the voltage on the signal pin and converts this to a temperature value. The engine coolant temperature value is use by the ECM for the engine protection system and engine emission control.

Component Location:
The engine coolant temperature sensor is located on the thermostat housing.

Shop Talk:
Verify the electronic control module (ECM) calibration is correct. Check the calibration revision history found on QuickServe® Online for applicable fixes to the calibration stored in the ECM. If necessary, recalibrate the ECM.

Two different failure modes of the engine coolant temperature sensor can trigger this fault code. Either the sensor is not reading ambient air temperature after an extended period with the engine not running or the engine coolant temperature is not changing with engine operating conditions.

Possible causes of this fault code include:
• Stuck in-range engine coolant temperature sensor
• High resistance in the engine coolant temperature sensor signal or return lines.

Read More:
SPN 654 - FMI 5 (Fault Code 332)
SPN 629 - FMI 12 (Fault Code 343)


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2 Responses to "SPN 110 - FMI 2 (Fault Code 334)"

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