Overview
| CODE | REASON | EFFECT |
| Fault Code: 146 PID: P110 SPN: 110 FMI: 0/16 LAMP: Amber SRT: |
Engine coolant temperature is above the engine protection warning limit.
|
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 lamp 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
- The ECM illuminates the amber CHECK ENGINE lamp immediately when the diagnostic runs and fails.
- The torque output of the engine will be reduced.
Conditions for Clearing the Fault Code
- To validate the repair using a Diagnostic Road Test, utilize a route that incorporates both stop and go city type driving and steady state highway type driving. It may be necessary to load the unit for certain diagnostics in the ECM to run.
- To validate the repair using a Chassis Dynamometer, utilize a routine that incorporates acceleration and motoring events, steady state highway type operation, and load. This will simulate normal driving and allow the diagnostics in the ECM to run.
- The fault code status displayed by the recommended Cummins® electronic service tool or equivalent will change to INACTIVE immediately after the diagnostic runs and passes.
- The ECM will turn off the amber CHECK ENGINE lamp immediately after the diagnostic runs and passes.
- The “Reset All Faults” command in the recommended Cummins® electronic service tool or equivalent 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.
Troubleshooting Summary
- Check for primary fault codes
- Coolant level check
- Cooling fan component inspection
- Radiator is externally obstructed
- Radiator shutters malfunctioning (if equipped)
- Coolant temperature sensor resistance check
- Fan clutch operates incorrectly
- Thermostat is malfunctioning
- Out-of-chassis opening temperature test
- Combustion gases entering the cooling system
- ECM calibration revision history check
Solution: S00002207
Verification
Conditions
- Turn keyswitch ON.
- Connect the recommended Cummins® electronic service tool or equivalent.
Action
- Use the recommended Cummins® electronic service tool or equivalent to read the fault codes.
Specification
Before troubleshooting this fault code, troubleshoot any fault code that is active or has more than one inactive count within the last 25 engine operating hours from the following list:
- Engine coolant temperature: 144, 145
Linked Solutions
- None
Repair
- Perform a search on the appropriate fault codes.
Validation
- None
Solution: S00010538
Verification
Conditions
- Turn keyswitch OFF.
Action
- Visually inspect the coolant level.
- Perform the Coolant System Pressure Test.
- Visually inspect for external coolant leaks.
Specification
- If the coolant level is low and there are signs of external coolant leaks, then reset the search to external coolant leak.
- If the coolant level is low and there are no signs of external coolant leaks, then reset the search to internal coolant leak.
Linked Solutions
- None
Repair
- No additional action is required for this solution.
Validation
- None
Solution: S00001686
Verification
Conditions
- Turn keyswitch OFF.
Action
Inspect the following components if applicable:
- Visually inspect the cooling fan and cooling fan blades.
- Visually inspect the cooling fan shroud.
- Visually inspect the recirculation baffles.
- Inspect the cooling fan belt.
- Visually inspect the cooling fan hub assembly.
- Visually inspect the automatic cooling fan belt tensioner.
Specification
- If any damage is found, then proceed to the Repair section.
Linked Solutions
- None
Repair
Repair or replace only the components that were found to be out of specification.
- Adjust, repair, or replace the component preventing correct cooling fan operation.
Refer to OEM Service Manual
Validation
- Connect all components
- Connect the recommended Cummins® electronic service tool or equivalent.
- Disable the fault code.
- Operate the engine within the “Conditions for Clearing the Fault Code” found in the Overview section of the troubleshooting procedure.
- Verify that the fault code is no longer active.
- Check ECM Calibration Revision History
- Use the recommended Cummins® electronic service tool or equivalent to find the current ECM code and revision number in the ECM.
- Compare the ECM code and revision number in the ECM to the calibration revisions listed in the ECM Calibration Revision History Database for applicable changes related to this fault code.
- Refer to ECM Calibration Revision History Database.
Solution: S00000485
Verification
Conditions
- Turn keyswitch OFF.
Action
- Visually inspect the radiator for damage.
- Visually inspect the radiator for any type of external obstruction.
- Check for closed cold weather radiator cover or winterfront.
Specification
- If any damage is found, then proceed to the Repair section.
Linked Solutions
- None
Repair
Repair or replace only the components that were found to be out of specification.
- Repair or replace the restricted radiator.
Refer to OEM Service Manual
- Remove the obstruction.
Refer to OEM Service Manual
- Repair or replace cold weather radiator cover or winterfront.
Refer to OEM Service Manual
Validation
- Connect all components
- Connect the recommended Cummins® electronic service tool or equivalent.
- Disable the fault code.
- Operate the engine within the “Conditions for Clearing the Fault Code” found in the Overview section of the troubleshooting procedure.
- Verify that the fault code is no longer active.
- Check ECM Calibration Revision History
- Use the recommended Cummins® electronic service tool or equivalent to find the current ECM code and revision number in the ECM.
- Compare the ECM code and revision number in the ECM to the calibration revisions listed in the ECM Calibration Revision History Database for applicable changes related to this fault code.
- Refer to ECM Calibration Revision History Database.
Solution: S00000484
Verification
Conditions
- Turn keyswitch OFF.
Action
- Manually operate the radiator shutters.
Refer to OEM Service Manual
- Check the shutterstat setting.
Refer to OEM Service Manual
Specification
- If any of the inspections are not within specification, then proceed to the Repair section.
Linked Solutions
- None
Repair
- Repair or replace the malfunctioning radiator shutters or shutterstat.
Refer to OEM Service Manual
Validation
- Connect all components
- Connect the recommended Cummins® electronic service tool or equivalent.
- Disable the fault code.
- Operate the engine within the “Conditions for Clearing the Fault Code” found in the Overview section of the troubleshooting procedure.
- Verify that the fault code is no longer active.
- Check ECM Calibration Revision History
- Use the recommended Cummins® electronic service tool or equivalent to find the current ECM code and revision number in the ECM.
- Compare the ECM code and revision number in the ECM to the calibration revisions listed in the ECM Calibration Revision History Database for applicable changes related to this fault code.
- Refer to ECM Calibration Revision History Database.
Solution: S00006285
Verification
Conditions
- Turn keyswitch OFF.
- Disconnect the coolant temperature sensor from the engine wiring harness.
Action
- Inspect the pins and connectors for damage.
- Measure the resistance of the coolant temperature sensor.
Specification
- If the resistance is not within specification, then proceed to the Repair section.
Linked Solutions
- None
Validation
- Connect all components
- Connect the recommended Cummins® electronic service tool or equivalent.
- Disable the fault code.
- Operate the engine within the “Conditions for Clearing the Fault Code” found in the Overview section of the troubleshooting procedure.
- Verify that the fault code is no longer active.
- Check ECM Calibration Revision History
- Use the recommended Cummins® electronic service tool or equivalent to find the current ECM code and revision number in the ECM.
- Compare the ECM code and revision number in the ECM to the calibration revisions listed in the ECM Calibration Revision History Database for applicable changes related to this fault code.
- Refer to ECM Calibration Revision History Database.
Solution: S00000476
Verification
Conditions
- Turn keyswitch ON.
- Connect the recommended Cummins® electronic service tool or equivalent.
Action
- Check the adjustable parameters settings.
Ensure the following adjustable parameters are set correctly for the application:
- Fan Control Logic.
- Fan Control Switch.
- Air Conditioner Pressure Switch Input.
- Use the recommended Cummins® electronic service tool or equivalent.
- Perform the Fan Override Test.
- Verify that the fan operates correctly.
- Verify the fan is engaging at the correct engine temperature.
Refer to OEM Service Manual
Specification
- If the fan does not engage at the correct engine temperature, then a malfunctioning fan clutch has been detected.
Linked Solutions
- None
Repair
- Adjust, repair, or replace the component preventing correct cooling fan operation.
Refer to OEM Service Manual
Validation
- Connect all components
- Connect the recommended Cummins® electronic service tool or equivalent.
- Disable the fault code.
- Operate the engine within the “Conditions for Clearing the Fault Code” found in the Overview section of the troubleshooting procedure.
- Verify that the fault code is no longer active.
- Check ECM Calibration Revision History
- Use the recommended Cummins® electronic service tool or equivalent to find the current ECM code and revision number in the ECM.
- Compare the ECM code and revision number in the ECM to the calibration revisions listed in the ECM Calibration Revision History Database for applicable changes related to this fault code.
- Refer to ECM Calibration Revision History Database.
Solution: S00000785
Verification
Conditions
- Engine running.
Action
- Allow the engine to reach operating temperature.
- Check the thermostat opening temperature with an infrared temperature gun.
- Check the coolant thermostat for proper operation.
- Check for a damaged or leaking thermostat seal.
- If a temperature gun is not available or if the temperature gun reading is above the correct thermostat opening temperature, then proceed to Linked Solutions section.
Specification
- If any damage is noted or if the thermostat does not open at the correct temperature, then a malfunctioning coolant thermostat has been detected.
- If any damage or if the thermostat seal is found leaking, then a malfunctioning thermostat seal has been detected.
Repair
- Replace the engine coolant thermostat.
A new thermostat seal should be used when replacing the engine coolant thermostat.
If the thermostat seal is damaged, the engine coolant thermostat will still need to be replaced since the thermostat seal is not a separately serviceable item.
Validation
- Connect all components
- Connect the recommended Cummins® electronic service tool or equivalent.
- Disable the fault code.
- Operate the engine within the “Conditions for Clearing the Fault Code” found in the Overview section of the troubleshooting procedure.
- Verify that the fault code is no longer active.
- Check ECM Calibration Revision History
- Use the recommended Cummins® electronic service tool or equivalent to find the current ECM code and revision number in the ECM.
- Compare the ECM code and revision number in the ECM to the calibration revisions listed in the ECM Calibration Revision History Database for applicable changes related to this fault code.
- Refer to ECM Calibration Revision History Database.
Solution: S00001359
Verification
Conditions
- Turn keyswitch OFF.
Specification
- If any damage is noted or if the thermostat does not open at the correct temperature, then a malfunctioning coolant thermostat has been detected.
- If any damage or if the thermostat seal is found leaking, then a malfunctioning thermostat seal has been detected.
Linked Solutions
- None
Repair
- Replace the engine coolant thermostat.
A new thermostat seal should be used when replacing the engine coolant thermostat.
If the thermostat seal is damaged, the engine coolant thermostat will still need to be replaced since the thermostat seal is not a separately serviceable item.
Validation
- Connect all components
- Connect the recommended Cummins® electronic service tool or equivalent.
- Disable the fault code.
- Operate the engine within the “Conditions for Clearing the Fault Code” found in the Overview section of the troubleshooting procedure.
- Verify that the fault code is no longer active.
- Check ECM Calibration Revision History
- Use the recommended Cummins® electronic service tool or equivalent to find the current ECM code and revision number in the ECM.
- Compare the ECM code and revision number in the ECM to the calibration revisions listed in the ECM Calibration Revision History Database for applicable changes related to this fault code.
- Refer to ECM Calibration Revision History Database.
Solution: S00001960
Verification
Conditions
- None
Action
- Check for air or combustion gases in the cooling system.
- Perform the combustion gas leak test.
Specification
- If air bubbles are found during the combustion gas test and did not change colors (Blue to Yellow or Green), then a malfunctioning air compressor has been determined.
- If the combustion gas test changed colors (Blue to Yellow or Green), then a malfunctioning engine cylinder head gasket has been determined.
Linked Solutions
- None
Repair
Repair or replace only the components that were found to be out of specification.
- Replace the air compressor cylinder head.
- Replace the cylinder head gasket.
Validation
- Connect all components
- Connect the recommended Cummins® electronic service tool or equivalent.
- Disable the fault code.
- Operate the engine within the “Conditions for Clearing the Fault Code” found in the Overview section of the troubleshooting procedure.
- Verify that the fault code is no longer active.
- Check ECM Calibration Revision History
- Use the recommended Cummins® electronic service tool or equivalent to find the current ECM code and revision number in the ECM.
- Compare the ECM code and revision number in the ECM to the calibration revisions listed in the ECM Calibration Revision History Database for applicable changes related to this fault code.
- Refer to ECM Calibration Revision History Database.
Solution: S00000443
Verification
Conditions
- Connect all components.
- Turn keyswitch ON.
- Connect the recommended Cummins® electronic service tool or equivalent.
Action
- Use the recommended Cummins® electronic service tool or equivalent to read the fault codes.
- Use the recommended Cummins® electronic service tool or equivalent to find the current ECM code and revision number in the ECM.
- Compare the ECM code and revision number in the ECM to the calibration revision listed in the ECM calibration revision history for applicable changes.
Specification
- If a calibration update for this fault code is available, the ECM calibration revision must be that revision or higher.
Linked Solutions
- None
Repair
- Prior to downloading the ECM calibration, check to see that all job images and all other troubleshooting has been documented as downloading an ECM calibration will remove the fault codes on the ECM.
- Download the updated ECM calibration code.
Validation
- Connect all components
- Connect the recommended Cummins® electronic service tool or equivalent.
- Disable the fault code.
- Operate the engine within the “Conditions for Clearing the Fault Code” found in the Overview section of the troubleshooting procedure.
- Verify that the fault code is no longer active.
- Check ECM Calibration Revision History
- Use the recommended Cummins® electronic service tool or equivalent to find the current ECM code and revision number in the ECM.
- Compare the ECM code and revision number in the ECM to the calibration revisions listed in the ECM Calibration Revision History Database for applicable changes related to this fault code.
- Refer to ECM Calibration Revision History Database.
If all steps have been completed and no root cause has been identified, then follow the technical escalation process.