Mazda 626 MX-6 Workshop Manual page 242

4 B TROUBLESHOOTING WITH SST
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)
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)
Is same Code No. present after performing after­
repair procedure? (Refer to page 4B—11)
Are engine control unit 2 1 and 2C terminal voltages
OK? (Refer to page 4B—106)
4B-22
YES
NO
NO
Control unit
2 1
2C
YES
Resistance
14.5-17.8 kfl
2 .2 - 2.7 kfl
1 .0 - 1.3 kfl
fl
500-640
fl
280-350
YES
YES
YES
Repair or replace connector
PC: Open circuit in wiring harness from water thermo
sensor to engine control unit
NO
Replace water thermo sensor
NO
Water thermo sensor and circuit OK
NO
PC: Engine short circuit in wiring harness
PC: Engine control unit malfunction
PC: Possible Cause
86U04B-013