sensor YAMAHA WR 250F 2010 Owner's Manual
Page 230 of 232
7-21
SIGNALING SYSTEM
CHECKING THE COUPLERS AND 
LEADS CONNECTION
1. Check:• Couplers and leads connection
Rust/dust/looseness/short-circuit
→ Repair or replace.
CHECKING THE MULTI-FUNCTION 
DISPLAY INPUT VOLTAGE
1. Disconnect the multi-function dis- play coupler.
2. Set the main switch to "ON".
3. Measure:
• Multi-function display input volt-age
Out of specification →Replace 
wire harness.
Make sure that a short-circuit does 
not develop between the terminals 
because it may cause damage to 
electrical components.
CHECKING THE MULTI-FUNCTION 
DISPLAY OUTPUT VOLTAGE
1. Disconnect the multi-function dis- play coupler.
2. Set the main switch to "ON".
3. Measure: • Multi-function display output volt-age
Out of specification →Replace 
multi-function display.
Make sure that a short-circuit does 
not develop between the terminals 
because it may cause damage to 
electrical components.
CHECKING THE SPEED SENSOR 
OUTPUT VOLTAGE
1. Insert the thin electric conductors 
"1" (lead) into the speed sensor 
coupler "2", as shown, and con-
nect the tester to them.
• Do not insert the electric conduc-tors more than required because 
it may reduce the waterproof 
function of the coupler.
• Make sure that a short-circuit  does not develop between the 
terminals because it may cause 
damage to electrical compo-
nents.
2. Set the main switch to "ON".
3. Measure:
• Speed sensor output voltageOutput voltage not correct →Re-
place the speed sensor.
Measurement steps:
a. Elevate the front wheel and slowly 
rotate it.
b. Measure the voltage (DCV) of  white lead and black lead. With 
each full rotation of the front 
wheel, the voltage reading should 
cycle from 0.6 V to 4.8 V to 0.6 V 
to 4.8 V.
Tester (+) lead →Brown lead "1"
Tester (-) lead →Black lead "2"
Multi-func- tion dis-
play input  voltage Tester se-
lector posi- tion
10 V or  more DCV-20
Tester (+) lead →Red lead "1"
Tester (-) lead →Black/White lead 
"2"
Multi-func-tion dis-
play output 
voltage Tester se-
lector posi- tion
4.5 V or  more DCV-20
Tester (+) lead
→White lead "3"
Tester (-) lead →Black lead "4"