Sym Wolf SB 250 Ni Service Manual page 58

TW sensor:
Resistance value measurement
Function Description:
Powered by 5V DC from ECU. It has the two-pin socket on the
●
sensor. One terminal is for voltage output, and the other terminal
is for ground.
The major component of TA sensor is a variable resistor of
●
negative temperature coefficient
Installed on the cylinder head, the resistor in TW sensor varies
●
with temperature variation and sends voltage signals for ECU to
calculate the intake air temperature; then, ECU adjusts injection
time and ignition angle.
Testing Procedures:
Resistance value measurement:
Remove the TW sensor from the vehicle.
●
Use the "Ohmmeter" Ohm stalls to inspect sensor resistance.
●
Detection judge:
( )
℃
Temperature
-20
40
100
Treatment of abnormal phenomena:
Damaged TW sensor or poor connector contact.
●
Check if the wire harness abnormal.
●
If TA sensor possibly failed, it is suggested to replace with a new
●
one.
3. Fuel Injection System
(KΩ)
Resistance value
18.8 ± 2.4
1.136 ± 0.1
0.1553 ± 0.007
3-19