JLG 450A_AJ Series II Service Manual - Manual (Page 182)

SECTION 3 - CHASSIS & TURNTABLE
3-142 – JLG Lift – 3121290
DTC 601- Microprocessor Failure - FLASH
• Engine Control Module- Flash Memory.
• Check Condition- Key on.
• Fault Condition- Internal microprocessor error.
• Corrective Action(s)- Illuminate MIL and/or sound audible
warning or illuminate secondary warning lamp, disable
adaptive fueling correction for remainder of key cycle, rec-
ommend power derate 2 and low rev limit to reduce possi-
ble engine damage and/or overspeed condition.
• Non-emissions related fault.
The ECM has checks that must be satisfied each time an
instruction is executed. Several different things can happen
within the microprocessor that will cause this fault.
If this fault sets, the ECM will reset itself and log the code. The
fault should be configured to never forget and will not self-
erase and will not clear until a technician performs diagnostics
and manually clears the code. This fault should be configured
to set a power derate 2 and low rev limit to reduce possible
engine damage and reduce possibility of an overspeed condi-
tion. A fault of flash memory can occur for any calibration vari-
able set and thus could cause undesirable operation.