ELM320
OBD
Interface
Notes: -
NPN transistors are
2N3904 or similar
78L05
16
+5V
750W
(Battery
Positive)
‘Power On’
LED
-
-
PNP transistors are
2N3906 or similar
0.47µF
5
Diodes are 1N4148,
1N4001, etc.
(Signal
Ground)
+5V
4.7KW
2
(Bus +)
4.7KW
10KW
10
(Bus -)
+5V
+5V
0.01µF
2.7KW
2.7KW
+5V
1
2
3
4
8
7
6
5
27pF
3.58MHz
RS232
Interface
10KW
27pF
3 (RxD)
+5V
+5V
4.7KW
0.1µF
10KW
7 (SG)
47KW
4.7KW
2 (TxD)
4.7KW
100KW
Figure 4. Typical OBD to RS232 Interface
ELM320DSC
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