Testing & Diagnosis: Testing
- Turn ignition off. Remove harness connectors "A" and "B" from ECU. Make sure to press down on harness connector lock when connecting or disconnecting harness connector. Turn Mitsubishi ECI system checker check switch to "OFF" position.
- Set select switch of checker to A. Connect the adapter to the connectors of ECI checker, and connect adapter to carburetor control unit and harness connectors. Place ECI checker on front passenger's seat. Perform checks listed in check chart.
- If checker shows any departure from specifications, check corresponding sensor and related electrical wiring and repair or replace as necessary. Recheck with ECI checker.
NOTE:
During checks 1 through 12, finish each step quickly and switch off ignition after each step to save current consumption and protect battery.
ECI SYSTEM CHECK PROCEDURE CHART - SELECT SWITCH POSITION A
| Switch Position; Check Item | Test Condition | Normal Volts | ECU Term |
|---|---|---|---|
| 1; Power Supply | Ignition switch OFF - ON | 11 - 13V | A-7 |
| 2; Distributor Advance Vacuum Exchange Solenoid Valve | Idling | 13 - 15V | B-7 |
| " | 2,000 RPM | 0 - 1V | A-7 |
| 3; TP Sensor | Ignition Switch OFF - ON Accelerator closed | 0-0.6V | A-13 |
| " | Ignition Switch OFF - ON Accelerator wide opened | 4 - 4.5V | A-13 |
| 4; Coolant Temp. Sensor | Ignition switch OFF - ON 20°C (68°F) | 2.4-2.6V | A-12 |
| " | Ignition switch OFF - ON 40°C (104°F) | 1.4-1.6V | A-12 |
| " | Ignition switch OFF - ON 80°C (176°F) | .5 - .7V | A-12 |
| 5; Intake Air Temp. Sensor | Ignition switch OFF - ON 20°C (68°F) | 2.4-2.6V | A-4 |
| " | Ignition switch OFF - ON 40°C (104°F) | 1.4-1.6V | A-4 |
| " | Ignition switch OFF - ON 80°C (176°F) | .5 - .7V | A-4 |
| 6; Vacuum Switch | Ignition switch OFF - ON | N/A | A-5 |
| " | Idling | N/A | A-5 |
| 7; dle Up Control Solenoid Valve | Ignition switch OFF - ON | 0 - 0.6V | B-3 |
| 8; Enrichment Solenoid Valve | Ignition switch OFF - ON | 11 - 13V | B-54 |
| 9; A/C Cut Relay | Ignition switch OFF - ON A/C Switch OFF - ON | 0 - 0.6V | B-6 |
| 10; Power Supply for Sensor | Ignition switch OFF - ON | 5V | A-3 |
| 11; N/A | N/A | N/A | N/A |
| 12; Secondary Air Control Solenoid Valve | Ignition switch OFF - ON Coolant temperature 30-40°C (86-104°F) | 0-0.6V | B-4 |
ECI SYSTEM CHECK PROCEDURE CHART - SELECT SWITCH POSITION B
| Switch Position; Check Item | Test Condition | Normal Volts | ECU Term |
|---|---|---|---|
| 1; N/A | N/A | N/A | N/A |
| 2; Jet Mixture Solenoid Valve | Ignition switch OFF - ON | 11 - 13V | B-1 |
| " | Idling | N/A | B-1 |
| 3; Idle Up Control Solenoid Valve | Keep 1,500 RPM | 13 - 15V | B-3 |
| 4; Ignition Pulse | Idling | 12 - 15V | A-10 |
| " | 3,000 RPM | 11 - 13V | A-10 |
| 5; N/A | N/A | N/A | N/A |
| 6; Power Supply for Back Up | Idling | 13 - 15V | A-9 |
| 7; Deceleration Solenoid Valve | Idling | 0-0.6V | B-2 |
| 8; Oxygen Sensor | Keep 1,300 RPM after warming up | 0.4-1V Flashing 2.7V | A-1 |
| 9; Enrichment Solenoid Valve | N/A | N/A | B-5 |
| 10; N/A | N/A | N/A | N/A |
| 11; A/C Cut Relay | Ignition switch OFF - ON A/C switch OFF - ON at accel. wide opened | 11 - 13V | B-6 |
| 12; Secondary Air Control Solenoid Valve | Keep idling after warming up | 11 - 13V | B-4 |