C.E. Niehoff & Co. C520 Troubleshooting Guides - Manual (Page 3)

Page 3
TG0048A
Section 2: CAN/J1939 Diagnostics
CAN/J1939 Interface
DESCRIPTION AND OPERATION
The CEN A2-326 digital regulator is compatible with
SAE J1939 communications standard for vehicle net-
working.
CEN uses MIL-STD connector MS3112E12-10P to inter-
face between the A2-326 and the vehicle J1939 databus.
Mating connector is MS3116E12-10S or equivalent.
If J1939 connection is not used, the 10-pin connector
must be covered with connector cover MS3181-12CA or
equivalent. Message content is shown in Table 2.
Pin Identifi cation
TABLE 1 – J1939 Connector
Circuit Identifi cation
A
B
C
D
E
F
G
H
J
K
CANH
CANL
CAN SHIELD
Battery
Mfr use only
Mfr use only
Mfr use only
Temperature sensor
Voltage sensor
Current sensor
Figure 4 – J1939
Connector Pins
Regulator Readout Expected Reading
TABLE 2 – A2-326 Regulator/J1939 Readout Diagnostics (see Table 3)
Alternator Output Voltage 28 V System
Alternator Speed
Regulator Temperature
Alternator Output
Charging System Hours 13–15 V
1200 to 8000 RPM
Less than 257 F/125ºC
0–100%
>0 hours
Action—If Expected Reading Not Present
See Chart 1, page 6.
Check drive belt and charging system connections.
Decrease load on alternator.
Varies with load.
Check drive belt and charging system connections.
TABLE 3 – Message Data
PGN Name PGN Byte 1 Byte 2 Byte 3 Byte 4 Byte 5 Byte 6 Byte 7 Byte 8
ALT RPM 0xFED5 ALT RPM
ALT VOLT 0xFEF7 VOLT SETPOINT ALT VOLT REG IGN VOLT BATT VOLT
ALT TEMP 0xFEA7 REG TEMP BATT TEMP
PROPRIETARY #1 0xFFC8 BATT
CURRENT
SHUTDOWN
COUNT
BATT AGE HOUR METER MINUTES
(0-59)
ALT LOAD
PROPRIETARY #2 0xFFC9 Proprietary Content: For Manufacturer Test Only