Mazda MX-5 1990 Workshop Manual page 273

CONTROL SYSTEM
F
Terminal
Input
Output
Connection to
Test condition Voltage Remark
1R
0
Fan switch Fan operating (Engine coolant tempera-
ture over 97°C (207°F) or diagnosis con- Approx. OV
nector terminal TFA grounded)
Fan not operating (Idle) Approx. 12V
--
1S Blower control Blower control switch at mid, high or Ignition switch 0
Approx. OV
switch super high position
ON
Blower control switch OFF or low Approx. 12V
1T
- -
- -
-
1U 0 Headlight switch Headlights ON (Tail, parking, low beam/
Approx. 12V
high beam)
Headlights OFF OV
1V 0 Neutral or clutch Neutral position or clutch pedal
Approx.OV
switch
depressed
Other conditions Approx. 12V
2A
-
-
Ground (Injector) Constant OV
_.
2B
-
-
Ground (Output) Constant OV
- -
2C
- -
Ground (CPU) Constant OV
20
- -
Ground (Input) Constant
OV
1 - - - - - -
0-
Crank angle Ignition switch ON 2E Approx.
sensor (Ne-signal) OV or 5V
Idle Approx.2V
-
2F
- - - - -
-
--
--
- - - - - - - -
2G 0 Crank angle Ignition switch ON Approx.
sensor (G-sgnal) OV or 5V
~-
Approx. 1.5V
2H 0 Ground California spec. OV
Open Federal and Canada spec. Approx. 2V
21
0
Igniter
Ignition switch ON Below O.5V
Idle Approx. 1V
1---
2J 0 Ground Constant OV
2K 0 Airflow meter Constant 4.5-5.5V
2L
0
Throttle sensor Accelerator pedal released
Approx. 5V
(Power terminal)
Accelerator pedal fully depressed Approx. OV
2M
-
- -
-
- -
2N
0
Oxygen sensor Ignition switch ON OV
Idle (Cold engine) OV
--
Idle (After warm-up) 0-1V
Increase engine speed (After warm-up) O.5-1V
-
Deceleration O-OAV
20 0 Airflow meter Ignition switch ON Approx. 3.8V
Idle Approx. 3.3V
2P
0
Airflow sensor
(Intake air
At 20°C (68°F) Approx. 2.SV
thermosensor)
20 0 Water
Engine coolant temperature 20°C (68°F) Approx. 2.5V
thermosensor
After warm up Approx. OAV
2R
- - -
-
-
-
--'-.
F-129