Code No. 09 (Water Thermo Sensor) - Mazda 626 1989 Workshop Manual

4B
TROUBLESHOOTING WITH SST
Is there continuity between air flow sensor and
engine control unit?
Air flow sensor
D (RB wire)
E (RW wire)
Is there 12V at terminal B of air flow sensor
connector? (Refer to page 4B—85)
Is there continuity between terminal F of air flow
sensor and ground? (Refer to page 4B—85)

Code No. 09 (Water thermo sensor)

Are there poor connections in water thermo
sensor circuit?
Is there continuity between water thermo sensor and
engine control unit?
Water thermo sensor
A (YB wire)
B (LgY wire)
Is resistance of the water thermo sensor OK?
Resistance:
Coolant temp
-2 0 ° C ( -4 ° F )
^ 2 0 °C ( 68°F)
40 °C (104°F)
60 °C (140°F)
8 0 °C (176°F)
Is same Code No. present after performing after­
repair procedure? (Refer to page 4B— 12)
Are engine control unit 21 and 2C terminal voltages
OK? (Refer to page 4B—80)
4B—18
Engine control unit
2E
2B
YES
YES
YES
YES
NO
Engine control unit
2!
2C
YES
Resistance
1 4 .5 -1 7 .8 kJ2
2 . 2 - 2.7 kfl
1.0— 1.3 kfi
500—640 0
280—350 Q
YES
YES
NO
NO
PC: Open circuit in wiring harness
NO
PC: Open or short circuit in wiring harness from
terminal B to control relay
NO
PC: Open circuit in wiring harness
PC: • Engine control unit malfunction
• Short circuit in wiring from terminal D of air
flow sensor to engine control unit
Repair or replace connector
NO
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
PC: Short circuit in wiring harness
76F04B-013
PC: Possible Cause
- -