15" Ect Sensor Circuit Malfunction - Suzuki RM-z450 Owner's Service Manual

12-29 FI SYSTEM DIAGNOSIS

"15" ECT SENSOR CIRCUIT MALFUNCTION

DETECTED CONDITION
Output voltage is not within the following range.
0.1 V Sensor voltage < 4.8 V
ECT sensor
When using the multi-circuit tester, do not strongly touch the terminal of the ECM coupler with
a needle pointed tester probe to prevent the terminal damage or terminal bend.
INSPECTION
Step 1
1) Stop the engine.
2) Check the ECT sensor coupler for loose or poor contacts.
If OK, then measure the ECT sensor voltage at the wire side
coupler.
3) Disconnect the ECT sensor coupler.
4) Connect a 12 volts battery using the battery lead wire to ser-
vice coupler. ("12-22)
5) Insert the needle pointed probes to the lead wire coupler.
6) Measure the voltage between B/Bl wire terminal A and ground.
7) If OK, then measure the voltage between B/Bl wire terminal
A and B/Br wire terminal B.
# ECT sensor voltage: 4.5 – 5.5 V
! 09900-25008: Multi-circuit tester set
09900-25009: Needle pointed probe set
36890-28H00: Battery lead wire (option)
% Tester knob indication: Voltage (&)
Is the voltage OK?
YES Go to Step 2.
• Loose or poor contacts on the ECM coupler
(terminal L or N).
NO
• Open or short circuit in the B/Bl wire or B/Br wire.
B/BI
B/Br
CAUTION
(+ B/Bl – - Ground)
(+ B/Bl – - B/Br)
POSSIBLE CAUSE
• ECT sensor circuit open or short.
• ECT sensor malfunction.
• ECM malfunction.
1
1
ECM
ECT
E2
V