JLG 450A_AJ Series II Service Manual - Manual (Page 237)

SECTION 3 - CHASSIS & TURNTABLE
3121180 – JLG Lift – 3-187
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 audi-
ble warning or illuminate secondary warning lamp, dis-
able adaptive fueling correction for remainder of key
cycle, recommend power derate 2 and low rev limit to
reduce possible 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 hap-
pen 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 possi-
bility of an overspeed condition. A fault of flash memory
can occur for any calibration variable set and thus could
cause undesirable operation.