Cummins ISX12 CM2250 (2010-12) Fault Code: 197 PID: 2560 SPN: 111 FMI: 18 Coolant Level- Data Valid But Below Normal Operating Range- Moderately Severe Level

Circuit Description
The coolant level sensor is a switch and is used to measure the level of the engine coolant in the radiator top tank. The coolant level sensor is immersed in the coolant and returns a different signal voltage when immersed in coolant versus being out of the coolant. The engine control module (ECM) monitors the change in voltage caused by changes in the resistance of the sensor to determine the level of the engine coolant.

Component Location
The engine coolant level sensor is typically located in the radiator top tank or surge tank. Refer to the OEM service manual for a detailed component location view.

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

Conditions for Setting the Fault Codes
The ECM detects that the coolant level sensor signal voltage is higher than 3-VDC for more than 30 seconds, indicating very low coolant level.

Action Taken When the Fault Code is Active
The ECM illuminates the amber CHECK ENGINE light after 20 seconds when low engine coolant level has been detected.
The torque output of the engine may be reduced.
Exhaust gas recirculation (EGR) valve operation will be disabled.
Conditions for Clearing the Fault Code
To validate the repair, start the engine and let it idle for 1 minute.
The fault code status displayed by INSITE? electronic service tool will change to inactive immediately after the diagnostic runs and passes.
The ECM will turn off the amber CHECK ENGINE light immediately after the diagnostic runs and passes.
The ?Reset All Faults? command in INSITE? electronic service tool can be used to clear active and inactive faults.

Shop Talk
This fault code goes active when the coolant level inside the radiator top tank or surge tank drops below the sensor level. Fill the top tank with coolant.

If this fault code is active and the coolant level is not low, disconnect the coolant level sensor and check the connectors for traces of coolant. If coolant is found at the electrical connectors, the sensor has malfunctioned and must be replaced.

Reference the appropriate OEM wiring diagram when troubleshooting circuits that utilize wiring supplied by the OEM.

For intermittent power supply and datalink communication issues with Aftertreatment Components, it is highly recommended that the OEM Power Distribution Center fuses and relays be thoroughly checked for loose, missing or intermittent connections.

Note: It may not be possible to perform an aftertreatment diesel particulate filter (DPF) regeneration while this fault code is active.

Possible Cause:
1) ECM calibration