Yamaha GX1800, Service Manual, Page: 16 / 32

13
Self-diagnosis
While the engine is running, the diagnostic codes “a” can be checked by pushing the “Hour Volt” but-
ton “b” for approximately 8 seconds.
TIP:
Because the multifunction meter cannot display more than 1 diagnostic code even if there are multi-
ple diagnostic codes, using the YDIS is recommended.
Diagnostic code table
○
: Indicated
—: Not indicated
Code No. Item
Diagnostic code output
Multifunction
meter
YDIS
Diagnosis
Diagnosis
record
01 Normal
○
— —
13 Pulser coil *1
○ ○ ○
15 Engine temperature sensor
○ ○ ○
17 Knock sensor
○ ○ ○
19 Battery voltage
○ ○ ○
23 Air temperature sensor *2
○ ○ ○
24 Cam position sensor
○ ○ ○
29 Air pressure sensor *3
○ ○ ○
47 Slant detection switch
○ ○ ○
55 Steering sensor
○ ○ ○
65 EX. manifold water temp sensor *4
○ ○ ○
78 Reverse switch *5
○ ○ ○
112, 113, 114,
115, 116, 117,
118, 119, 121,
122, 123, 129,
136, 137, 138,
139, 141, 142,
143, 144, 145
ETV system
○ ○ ○
b
a