General <Electrical> - Except Evolution: Diagnosis Mitsubishi Lancer IX

CONNECTOR CONTINUITY AND VOLTAGE TEST

Required Special Tools

1. MB991219: Test Harness Set
2. MD998459: Test Harness

Follow the steps below to avoid causing poor connector contact and/or reduced waterproof performance of connectors when checking continuity and/or voltage at terminals of waterproof connectors.

Scheme 76

Scheme 77

1. If the circuit is to be checked in the closed state, use a special tool such as MD998459. CAUTION: Forcing the probe into the terminal may open the terminal, causing intermittent or poor contact and creating an open circuit.
2. If the connector is disconnected for checking and the facing part is the female pin side, use an appropriate male terminal for checking the contact pressure of connector pins (such as MB991219). CAUTION: Do not contact more than one terminal with the probe at the same time. Contacting two or more terminals at the same time may damage a circuit, possibly to the point of starting an electrical fire.
3. If the facing part is the male pin side, either carefully touch the probe to the pin so it does not accidently contact other pins, or use an appropriate female terminal.

HOW TO DIAGNOSE

The most important point in troubleshooting is to determine "Probable Cause." Once the probable causes are determined, parts to be checked can be limited to those associated with such probable causes. The determination of the probable causes must be based on a theory and be supported by facts and must not be based on intuition only.

TROUBLESHOOTING STEPS

If an attempt is made to solve a problem without going through correct steps for troubleshooting, the symptoms could become more complicated, resulting in failure to determine the causes correctly and making incorrect repairs. The four steps below should be followed in troubleshooting.

Observe the symptom carefully. Check if there are also other problems.

In determining the probable causes, it is necessary to study the wiring diagram to understand the circuit as a system. Knowledge of switches, relays and other parts is necessary for accurate analysis. The causes of similar problems in the past must be taken into account.

Troubleshooting is carried out by making step-by-step checks until the cause is found.

After the problems are corrected, be sure to check that the system operates correctly. Also check that new problems have not been caused by the repair.

Scheme 78

INFORMATION FOR DIAGNOSIS

This manual contains the harness diagrams as well as the individual circuit drawings, operational explanations, and troubleshooting hints for each component. The information is presented in the following manner

1. Connector diagrams show the connector positions, etc., on the actual vehicle as well as the harness path.
2. Circuit diagrams show the configuration of the circuit with all switches in their normal positions.
3. Operational explanations include circuit drawings of voltage flow when the switch is operated and how the component reacts.
4. Troubleshooting hints include numerous examples of problems which might occur. Most of the problems can be traced backward in a common-sense manner to the origin of the trouble. Problems whose origins may not be found in this manner are pursued through the various system circuits.

Note. Components of MFI, ETACS, etc. with ECU do not include 3 and 4 above. For this information, refer to a relevant section that includes details of these components.

Scheme 79

Scheme 80

Scheme 81

1. Sight and sound checks Check relay operation, blower motor rotation, light illumination, etc. Listen for a "click" when relay covers are pushed down.
2. Simple checks For example, if a headlight does not come on, a faulty fuse or poor grounding is suspected. Replace the fuse with a new one. Or use a jumper wire to ground the light to the body. Determine which part(s) is/are responsible for the problem.
3. Checking with instruments Use an appropriate instrument in an adequate range and read the indication correctly.

INSPECTION INSTRUMENTS

For inspection, use the following instruments

Scheme 82

Scheme 83

Scheme 84

Scheme 85

Scheme 86

1. Test lights A test light consists of a 12V bulb and lead wires. It is used to check voltages or short circuits. CAUTION: Never use a test light for checking ECU-related circuits or ECUs.
2. Self-powered test light A self-powered test light consists of a bulb, battery and lead wires connected in series. It is used to check continuity or grounding.
3. Jumper wire A jumper wire is used to close an open circuit. CAUTION: Never use a jumper wire to connect a power supply directly to a load.
4. Voltmeter A voltmeter is used to measure the circuit voltage. Normally, the positive (red lead) probe is applied to the point of voltage measurement and the negative (black lead) probe to the body ground. Use a digital voltmeter to check for voltage drop upstream and downstream of a component.
5. Ohmmeter An ohmmeter is used to check continuity or measure resistance of a switch or a coil. If the measuring range has been changed, the zero point must be adjusted before measurement.