PACCAR PX-9 CM2350 (2013-17) Fault Code:146 PID:110 SPN:110 FMI:16 Engine Coolant Temperature – Data Valid But Above Normal Operational Range – Moderately Severe Level

Reason:
Engine Coolant Temperature – Data Valid But Above Normal Operational Range – Moderately Severe Level. Engine coolant temperature is above engine protection warning limit.

Effect:
Progressive power and/or speed derate increasing in severity from time of alert. If the Engine Protection Shutdown feature is enabled, the engine will shut down 30 seconds after the red STOP lamps starts flashing.

Circuit Description:
The coolant temperature sensor is a variable resistor sensor and is used to measure the temperature of the coolant of the engine. The engine control module (ECM) supplies 5 volts to the coolant temperature signal circuit. The ECM monitors the change in voltage caused by changes in the resistance of the sensor to determine the coolant temperature.

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

Conditions for Running the Diagnostics:
This diagnostic runs continuously when the keyswitch is in the ON position or when the engine is running.

Conditions for Setting the Fault Codes:
The Engine Control Module (ECM) detected the engine coolant temperature was greater than 108°C [226°F] for more than 5 seconds.

Action Taken When the Fault Code is Active:
1) The ECM illuminates the amber CHECK ENGINE lamp immediately when the diagnostic runs and fails.
2) The torque output of the engine will be reduced.

Conditions for Clearing the Fault Code:
1) To validate the repair, perform a key cycle, start the engine and let it idle for 1 minute.
2) The fault code status displayed by INSITE™ electronic service tool will change to INACTIVE immediately after the diagnostic runs and passes.
3) The ECM will turn off the amber CHECK ENGINE lamp immediately after the diagnostic runs and passes.
4) The Reset All Faults command in INSITE™ electronic service tool can be used to clear active and inactive faults, as well as extinguish the MIL for OBD applications.

Shop Talk:
This fault code indicates that coolant temperature has exceeded the engine protection limit for high coolant temperature. Refer to Engine Coolant Temperature Above Normal symptom troubleshooting tree in the applicable engine service manual.

Possible Causes:
1) Faulty Coolant Temperature Sensor
2) Inactive fault codes
3) Damaged OEM harness
4) Damaged frequency throttle and circuit
5) Damaged connector pins
6) Short-to-ground in the frequency throttle
7) Faulty frequency throttle input voltage
8) Faulty ECM
9) Open circuit in the OEM harness
10) Pin short circuit to ground in the OEM harness
11) Pin-to-pin short circuit in the OEM harness