Suzuki RM-Z250 Service Manual page 221

12-38 FI SYSTEM DIAGNOSIS
Step 2
1) If necessary, connect the ECM coupler.
2) Disconnect the ECT sensor coupler.
3) Measure the ECT sensor resistance.
 ECT sensor resistance:
 09900-25008: Multi circuit tester set
 Tester knob indication: Resistance (Ω)
Is the resistance OK?
• B/Bl or B/Br wire open or shorted to ground, or
poor L or N connection.
• If wire and connection are OK, intermittent trou-
ble or faulty ECM.
YES
• Recheck each terminal and wire harness for
open circuit and poor connection.
• Replace the ECM with a known good one, and
inspect it again.
NO Replace the ECT sensor with a new one.
 ECT sensor specification
Engine Coolant Temp.
20 °C (68 °F)
50 °C (122 °F)
80 °C (176 °F)
110 °C (230 °F)
Approx. 2.58 kΩ at 20 °C (68 °F)
(Terminal – Terminal)
Resistance
Approx. 2.58 kΩ
Approx. 0.77 kΩ
Approx. 0.28 kΩ
Approx. 0.12 kΩ
2
2
ECM coupler (Harness side)