Service Manual Manual

SECTION 3 - 1CHASSIS & TURNTABLE
3121171 – JLG Lift – 3-139
Diagnostic Trouble Codes
The numeric diagnostic trouble codes assigned to the
faults in this section are cross-referenced to SAE’s "Rec-
ommended Practice for Diagnostic Trouble Code Defini-
tions" (SAE J2012). While these codes are recommended,
the manufacturer may define their own codes by assign-
ing a new number to the flash code in the diagnostic cali-
bration. This will assign both the DTC as displayed in
EDIS as well as the flash code output on the MIL output
pin. EDIS may be used to connect to the DGC ECM via
CAN.
CAN
The DGC supports SAE J1939 CAN based diagnostic
support. This includes:
• DM1: Active Diagnostic Trouble Codes
• DM2: Previously Active Diagnostic Trouble Codes
• DM3: Diagnostic Data Clear/Reset of Previously Active
DTCs
• DM4: Freeze Frame Parameters
• DM5: Diagnostic Readiness (bytes 1, 2, and 3 are sup-
ported)
• DM11: Diagnostic Data Clear/Reset For Active DTCs
• DM12: Emissions-Related Active Diagnostic Trouble
Codes
• DM19: Calibration Information
All diagnostic trouble codes broadcast over CAN will be
SAE J1939 DM1 and DM2 formatted messages. DGC
ECMs are compliant with J1939 OBD-M, supporting the
Diagnostic Messages above as well as user indicators and
CAN data defined in the OBD-M protocol. Faults available
for broadcast and their respective SPN/FMI numbers are
dependent on the application and engine calibration.
There are 4 CAN SPN/FMI lists available in the DGC soft-
ware set, contact EControls Inc. for a list of CAN SPN/
FMIs.
The data capture at the occurrence of a fault, known in the
ECM as fault snapshot (FSS), is available upon DM4
request. The following bytes are supported for DM4 if con-
figured in the ECM software:
• Byte 1: Freeze Frame Length
• Byte 2-6: SPN, FMI, SPN Conversion Method, and
Occurrence
• Byte 7: Manifold Absolute Pressure
• Byte 8-9: Engine Speed
• Byte 10: Engine Load (MAP based estimate)
• Byte 11: Engine Coolant Temperature
• Byte 14: # of starts since fault was last active
• Byte 15: Index into FSS_storage table for Fault Snap
Shot retrieval
Resetting active and previously active DTCs is handled
through DM11 and DM3, respectively DM1 and DM2 lamp
indicators are assigned to each fault based on the fault.s
diagnostic action as defined in the calibration. The lamps
are assigned based on the configuration outlined in Table
3-7.
MIL Output
The MIL output is used to convey fault information to the
equipment operator. The MIL is always on (grounded)
when the system is in a key-on (Vsw), engine-off state.
This provides assurance that the output is functional. If a
DTC is logged as previously-active (historic), the MIL will
send a single flash for the “Blink on-time” every “Blink off-
time.”
Table 3-7. J1939 Diagnostic Lamp Configuration
ECI DIAGNOSTIC ACTION J1939 LAMP
MIL MIL
Soft Warning Amber
Hard Warning, Low Rev Limit,
Shutdown
Red Stop
Power Derate 1 & 2 Protect
Forced Idle
None (use in combination with
other action)