Continuous Monitor
Continuous Monitor is a series of continuous diagnostic tests done by the Electronic Control
Module (ECM) to detect failure modes (Out of Range, In Range, and System Faults). During Continuous
Monitor the ignition switch is on.
• Out of Range High (Voltage over normal operating range)
• Out of Range Low (Voltage under normal operating range)
• In Range (In normal operating range but not correct for conditions)
• System Malfunction (System is not operating according to conditions)
If an input signal is out of range (over or under normal operating range), the ECM logs a fault and sets a Diagnostic Trouble Code (DTC). The ECM monitors the operation of systems for in range conditions to determine if systems are working in a normal operational range; If the ECM detects that a system falls outside a predetermined range, it will log a fault and set a DTC.
Each DTC has a three digit number to identify the source of a malfunction measured or monitored electronically. A fault is a malfunction measured or monitored electronically.
The ECM continuously monitors the Injection Control Pressure (ICP) system and the Air Management
System (AMS). If the ECM detects that a system falls outside a predetermined range, the ECM logs a fault
and sets a DTC.
During normal engine operation, the ECM automatically performs several tests to detect faults. When a fault is detected, the ECM often runs a fault management strategy to allow continued, though sometimes degraded, vehicle operation.
With the engine running, engine events are permanently recorded in the ECM; engine events can be retrieved with the Electronic Service Tool (EST).
Engine Events
Standard Engine Events
Standard engine events include excessive coolant temperature and engine rpm (over-speed).
Optional Engine Events
Optional engine events are monitored and recorded, if the engine is equipped with the optional Engine Warning Protection System (EWPS). Optional engine events recorded by the ECM include low coolant level and low oil pressure.
Engine Event Hours/Odometer
The ECM records engine events in two ways, hours and odometer readings.
Examples
• Overheat Hour 1
• Overheat Hour 2
• Overheat Odometer 1
• Overheat Odometer 2
The ECM stores the two most recent events. Two events could happen in the same hour, and two events
could happen in the same mile.
