Circuit DescriptionThe 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 coolant. The engine control module (ECM) monitors the change in the signal voltage to determine the level of the engine coolant. Component LocationThe engine coolant level sensor is typically located in the radiator top tank or surge tank. Refer to the OEM service manual for the location. Conditions for Running the DiagnosticsThis diagnostic...

Circuit DescriptionCertain anti-lock braking (ABS) controllers communicate with the engine control module (ECM) through the SAE J1939 data link. Under certain driving conditions, the anti-lock braking (ABS) controller can send a cruise control inhibit message to the ECM and cruise control will temporarily be disabled. Component LocationThe SAE J1939 data link wiring and the SAE J1939 devices vary by OEM options. Conditions for Running the DiagnosticsThis diagnostic runs continuously when the keyswitch is in the ON position or when the engine is running. Conditions for Setting the Fault CodesThe anti-lock bracking (ABS) controller detected certain driving conditions and inhibited cruise...

Circuit DescriptionThe ECM records the time from the completion of an active regeneration of the aftertreatment diesel particulate filter until the ECM request another active regeneration of the diesel particulate filter. Component LocationThe aftertreatment diesel particulate filter is located in the exhaust system and is installed by the original equipment manufacturer (OEM). Refer to the OEM service manual. Conditions for Running the DiagnosticsThis diagnostic only runs after successful completion of an active regeneration of the aftertreatment diesel particulate filter. Conditions for Setting the Fault CodesThe time between the completion of a successful active regeneration and the requests for another active...

Circuit DescriptionThe engine aftertreatment system monitors the soot load in the aftertreatment diesel particulate filter. Under normal operating conditions, the aftertreatment diesel particulate filter is self-cleaning, where soot is converted to carbon dioxide, nitrogen, and water. Under light load operating conditions, it can be necessary to perform a stationary regeneration of the aftertreatment diesel particulate filter. The soot load in the aftertreatment diesel particulate filter is estimated, using the aftertreatment differential pressure sensor and the calculated soot output of the engine. Component LocationThe aftertreatment diesel particulate filter differential pressure sensor is mounted on the diesel particulate filter. It is a...

Circuit DescriptionThe Engine Control Module (ECM) Idle Shutdown feature has an optional parameter for a shutdown accessory relay. When this parameter is set to “Installed”, the ECM sends a signal to energize the relay and turn off vehicle accessories during idle shutdown events. The idle shutdown relay return circuit varies by Original Equipment Manufacturer (OEM). The return circuit can be returned to the ECM through the ECM Return (General) or connected directly to ground. Refer to the OEM service manual to determine grounding configuration. Component LocationThe idle shutdown relay location varies by OEM. Refer to the OEM service manual to...