Yamaha MTN850-A 2017 Service Manual page 443

Fault code No.
Item
2 Connection of starter relay cou-
pler. Check the locking condition
of the coupler.
Disconnect the coupler and
check the pins (bent or broken
terminals and locking condition
of the pins).
3 Check the fuel injection system
fuse.
4 Wire harness continuity
between starter relay and ECU
coupler.
5 Wire harness continuity
between starter relay and bat-
tery.
6 Malfunction in ECU.
7 Delete the fault code and check
that the engine trouble warning
light goes off.
P1602
Malfunction in ECU internal circuit (malfunction of ECU power cut-
off function).
Improperly connected  Con-
nect the coupler securely or
replace the wire harness.
Blown fuse  Replace the fuse. Turn the main switch to "ON",
Open or short circuit  Replace
the wire harness.
Between starter relay and ECU
coupler.
red–red
Open or short circuit  Replace
the wire harness.
Between battery terminal and
starter relay.
red–red
Replace the ECU.
Confirm that the fault code has
a condition of "Recovered"
using the Yamaha diagnostic
tool, and then delete the fault
code.
8-86
FUEL INJECTION SYSTEM
Turn the main switch to "ON",
and then check the condition of
the fault code using the mal-
function mode of the Yamaha
diagnostic tool.
Condition is "Recovered"  Go
to item 7 and finish the service.
Condition is "Detected"  Go to
item 3.
and then check the condition of
the fault code using the mal-
function mode of the Yamaha
diagnostic tool.
Condition is "Recovered"  Go
to item 7 and finish the service.
Condition is "Detected"  Go to
item 4.
Turn the main switch to "ON",
and then check the condition of
the fault code using the mal-
function mode of the Yamaha
diagnostic tool.
Condition is "Recovered"  Go
to item 7 and finish the service.
Condition is "Detected"  Go to
item 5.
Turn the main switch to "ON",
and then check the condition of
the fault code using the mal-
function mode of the Yamaha
diagnostic tool.
Condition is "Recovered"  Go
to item 7 and finish the service.
Condition is "Detected"  Go to
item 6.
Service is finished.