Code No.09 Water Thermosensor; Code No.10 Intake Air Theamosensor (In Airflow Meter) - Mazda MX-5 1990 Workshop Manual

SELF-DIAGNOSIS FUNCTION
F
CODE NO.09 WATER THERMOSENSOR
STEP INSPECTION
ACTION
1 Are there any poor connections in water thermosensor
Yes Repair or replace connector
circuit?
No Go to next step
2
Is there continuity between water thermosensor and Yes Go to next step
ECU?
No
Check for open circuit in wiring from water ther-
Water thermosensor
ECU
mosensor to ECU
A (LlW) 20
B (B/LG) 20
3 Is resistance of water thermosensor OK? Yes Go to next step
No Replace water thermosensor
Coolant temp.
Resistance
-20°C ( -4°F)
14.6-17.8 kO
(Refer to page F-139)
20°C ( 68°F) 2.2-2.7 kO
80°C (176°F)
290-3500
4
Is same Code No. present after performing after-repair Yes Go to next step
procedure? (Refer to page F-88)
No Water thermosensor and circuit OK
5 Are ECU terminals 20 and 2D voltages OK? Yes Replace ECU (Refer to page F-127)
(Refer to page F-129)
No Check for short circuit in wiring from water ther-
mosensor to ECU
05UOFX-083
CODE NO.10 INTAKE AIR THEAMOSENSOR (IN AIRFLOW METER)
STEP
INSPECTION
ACTION
1 Are there any poor connections in intake air thermosen-
Yes Repair or replace connector
sor circuit?
No Go to next step
2
Is there continuity between intake air thermosensor (in
Yes Go to next step
airflow meter) and ECU?
- -
No
Check for open circuit in wiring from intake air
Intake air thermosensor
ECU
thermosensor (in airflow meter) to ECU
C (B/LG) 20
G (RIG)
2P
3 Is resistance of intake air thermosensor (in airflow meter)
Yes Go to next step
OK?
No Replace airflow meter (Refer to page F-135)
Terminal Temperature Resistance
C (S/RG) -20°C ( -4°F) 13.6-18.4 kO
-G (RIG)
20°C ( 68°F) 2.21-2.69 kO
60°C (140°F) 493-6670
4
Is same Code No. present after performing after-repair
Yes Go to next step
procedure? (Refer to page F-88)
No
Intake air thermosensor and circuit OK
5 Are engine control unit terminals 2P and 20 voltages Yes Replace ECU (Refer to page F-127)
OK? (Refer to page F-129)
No Check for short circuit in wiring from intake air
thermosensor to ECU
05UOFX-084
CODE NO.14 ATMOSPHERIC PRESSURE SENSOR
Replace ECU (Refer to page F-127)
05UOFX-085
F-85