| ECU power supply from ignition sw. |
| 18 and ground |
Ignition ON |
Battery volts (about 12 volts DC) |
| ECU power supply from main relay |
| 9 and ground |
Ignition OFF, terminal 21 grounded |
Battery volts (about 12 volts DC) |
| ECU ground connections |
| 5 and ground, 11 and ground, 19 and ground, 11 and 19, 25 and ground |
Ignition OFF |
Continuity |
| Fuel pump power supply from main relay |
| 5 and ground, 11 and ground, 19 and ground, 11 and 19, 25 and ground |
Ignition ON, terminal 17 grounded |
Fuel pumps should operate |
| Fuel injectors |
| 13 (at ECU connector) and 87/2 (at main relay) |
Ignition OFF |
4.0 ohms |
| Coolant temp. sensor |
| 2 and ground |
Ignition OFF |
|
| Throttle switch idle contacts |
| 3 and ground |
Throttle closed |
Continuity |
| 3 and ground |
Throttle open |
No continuity |
| Throttle switch full-throttle contacts |
| 12 and ground |
Throttle fully open |
Continuity |
| 12 and ground |
Throttle less than fully open |
No continuity |
| Air mass meter power supply |
| 5 at air mass meter connector (Orange wire) and ground |
Ignition ON, terminal 21 grounded |
Battery voltage (apx 12 volts DC) |
| Air mass meter ground |
| 1 at air mass meter connector (Black wire) and ground |
Ignition OFF |
Continuity |
| Air mass meter hot wire |
| 6 and 7 |
Ignition OFF |
3.5-4.0 ohms |
| Air mass meter idle mixture potentiometer |
| 6 and 14 |
Basic check |
0-1000 ohms (varies with idle mixture adjustment) |
| Engine RPM signal |
| 1 and ground |
Ignition ON |
Battery voltage (apx 12 volts DC) |
| Oxygen sensor wiring harness |
| 20 and ground |
Oxygen sensor connected |
No continuity |
| 20 and ground |
Separate connector and connect Green wire to ground |
Continuity |
| Lambda-sond test connector |
| 22 and ground |
Ignition OFF |
No continuity |
| Idle speed test connector |
| 12 and ground |
Ignition OFF |
No continuity |
| Air control valve |
| 10 (at ECU connector) 87/2 (at main relay) |
Ignition OFF |
apx 20 ohms |
| 23 (at ECU connector) 87/2 (at main relay) |
Ignition OFF |
apx 20 ohms |
| AC microswitch |
| 16 and ground |
AC switch OFF |
No continuity |
| 16 and ground |
AC switch ON |
Resistance varies as knob turns |