Coolant Level Sensor 1 Circuit – Voltage Above Normal, or Shorted to High Source
|Fault Code: 195
Coolant Level Sensor 1 Circuit – Voltage Above Normal, or Shorted to High Source. High signal voltage detected at engine coolant level circuit.
None on performance.
ISX and ISM – Engine Coolant Level Sensor 1 Circuit
The electronic control module (ECM) supplies a 5 volt supply to the engine coolant level sensor using a common sensor supply circuit. The ECM also provides a ground on the sensor return circuit. The engine coolant level sensor provides a signal to the ECM on the engine coolant level sensor signal circuit. This sensor signal voltage changes based on the coolant level in the expansion tank.
The engine coolant level sensor is typically located in the radiator top tank or surge tank. Refer to the OEM troubleshooting and repair manual for location.
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 ECM detects that the coolant level signal voltage is greater than 4.5-VDC for more than 1 second.
Action Taken When the Fault Code is Active
- The ECM illuminates the amber CHECK ENGINE light immediately when the diagnostic runs and fails.
- No engine protection will be available for low coolant level.
Conditions for Clearing the Fault Code
The ECM will turn off the amber CHECK ENGINE light immediately after the diagnostic runs and passes.
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. Refer to Procedure 019-032 (ECM Calibration Code) in Section 19 in the corresponding Troubleshooting and Repair Manual for the engine being serviced.
Possible causes of this fault code include:
- Open return circuit in the engine harness, connectors, or sensor.
- Signal circuit shorted to sensor supply or battery voltage.
- Sensor supply circuit shorted to battery voltage.