Mazda MX-5 1990 Workshop Manual page 277

CONTROL SYSTEM
F
Terminal Connection to Abnormal voltage Possible cause
2K
Airflow meter
Always approx. OV • Short circuit in wiring from ECU terminal 2K to air-
flow meter
• Poor connection at ECU connector
• ECU malfunction
Below 4.SV or above S.SV
• ECU malfunction
2L Throttle sensor Always approx. OV • Throttle sensor malfunction (Refer to page F-136)
(Power terminal) • Short circuit in wiring from ECU terminal 2L to throt-
tle sensor
• Poor connection at ECU connector
• ECU malfunction
Always approx. 5V
• Throttle sensor misadjustment (Refer to page F-136)
• Open circuit in wiring from ECU terminal 2L to throt-
tle sensor
• Open circuit in wiring from throttle sensor to ground
2N Oxygen sensor OV after warm-up • Refer to .Code No.1S troubleshooting
(Refer to page F-86)
Always approx. 1 V • Refer to Code NO.1? troubleshooting
after warm-up
(Refer to page F-86)
20 Airflow meter Always approx. OV or • Refer to Code No.OB troubleshooting
approx. 5V (Refer to page F-84)
2P Airflow meter (Intake air Always approx. OV or
• Refer to Code No.10 troubleshooting
thermosensor)
approx. 5V (Refer to page F-85)
• Intake air thermosensor malfunction
(Refer to page F-135)
20 Water thermosensor Always approx. OV or • Refer to Code NO.09 troubleshooting
approx. 5V (Refer to page F-85)
• Water thermosensor malfunction
(Refer to page F-136)
2U Injector Always approx. OV
• Main relay malfunction
2V
(Refer to page F-139)
Open or short circuit in wiring from injector to ECU
terminal 2U or 2V
Always approx. 12V
• ECU malfnction
2W ISC valve Always approx. OV or
• Refer to Code No.34 troubleshooting
approx. 12V
(Refer to page F-87)
• ISC valve malfunction
(Refer to page F-99)
2X Solenoid valve Always approx. OV or • Refer to Code No.26 troubleshooting
(Purge control) approx. 12V (Refer to page F-87)
• Solenoid valve (Purge control) malfunction
(Refer to page F-119)
05UOFX-202
F-133