Code No. 09 (Water Thermo Sensor) - Mazda 626 MX-6 Workshop Manual

Code No. 09 (Water thermo sensor)

Are there poor connections at water thermo
sensor circuit?
Is there continuity between water thermo sensor and
control unit?
Water thermo sensor
A (YB wire)
B (LgY wire)
YES
Is resistance of the water thermo sensor OK?
Resistance:
Coolant temp
-20°C ( — 4°F)
20°C ( 68°F)
40°C (104°F)
60°C (140°F)
80°C (176°F)
YES
Is same Code No. present after performing after­
repair procedure? (Refer to page 4A—11)
YES
Are engine control unit 2 1 and 2C terminal voltages
OK? (Refer to page 4A—91)
YES
YES
NO
NO
Control unit
21
2C
Resistance
14.5—17.8 kfl
NO
2 .2 - 2.7 kfl
1 .0 - 1.3 kfl
500-640 fl
fl
280-350
NO
NO
TROUBLESHOOTING WITH SST
Repair or replace connector
PC: Open circuit in wiring harness from water thermo
sensor to engine control unit
Replace water thermo sensor
Water thermo sensor and circuit OK
PC: Engine short circuit in wiring harness
PC: Engine control unit malfunction
4 A
PC: Possible Cause
86U04A-023
4 A -1 7