Operation - Section 3 OM3024.3 8/00 Page 3-36 Instrument Panel and Indicators Quantum FUEL SYSTEM DIAGNOSTICS - CUMMINS Engine Only - above, this switch will permit determination of the kind of “fault(s)” detected. Determining “FAULT” Codes The CHECK ENGINE Monitor Light (7, Figure 3-12) monitors the Quantum Fuel Control system. When the keyswitch is turned “On”, this light should illumi- nate for about 2 seconds and then turn “Off”, if no “faults” are detected in the system. Quantum fault codes consist of three numerical digits. Each digit is indicated with up to five light flashes (CHECK ENGINE Monitor Light) per each digit. There is a short pause between each digit of the fault code.
Once all three digits are flashed, there is a longer pause, followed by a repeating of the same fault code sequence. 1. To determine an active Quantum “fault”, turn the keyswitch to the OFF position. Be sure engine completely stops, if it was running. 2. Turn keyswitch to ON position (engine not run- ning) and press Lamp Test switch to the left (“ position) for 1 – 2 seconds, then release (switch is spring-loaded to the middle, “OFF”, position). If the light stays ON, or FLASHES, then active “faults” have been detected by the system and the engine should not be started. Refer to DETERMINING “FAULT” CODES below.
During engine operation, if a “fault” is detected in the system, the light will turn ON and stay on for “Warning faults”, or it will turn “ON and FLASH” for more severe faults that can affect engine operation and require immediate attention. 3. If there is an active fault after releasing the switch, there will be a short pause, followed by the first fault code. “Warning” faults (light ON) are ones that require attention in the near future, but in most conditions will not greatly affect governing performance. “Severe” faults (light FLASHING) are ones that require immediate attention, because Quantum governor performance could be significanly affected, resulting in a backup mode of operation .
Active fault conditions MUST be corrected as soon as possible . The Lamp Test/Diagnostic Test Switch (14, Figure 3-12) may be used to activate the Quantum Fuel System diagnostic codes. When the Quantum fuel system detects a “fault” and the CHECK ENGINE Monitor Light (7, Figure 3-12) illuminates as described