How To Use OEM Diagnostic Procedures

When checking for an open circuit or short circuit, it is important to check the connector connection and the condition of the terminals.





OPEN CIRCUIT
This could be due to a disconnected wire harness, faulty contact in the connector, a connector terminal pulled out, etc.

1. A wire rarely breaks in the middle of it's length. Most cases occur at the connector. In particular, carefully check the connectors of sensors and actuators.
2. Faulty contact could be due to rusting of the connector terminals, to foreign materials entering the terminals or a drop in the contact pressure between the male and female terminals of the connector. Simply disconnecting and reconnecting the connectors once changes the condition of the connection and may result in a return to normal operation. Therefore, in troubleshooting, if no abnormality is found in the wire harness and connector check, but the problem disappears after the check, them the cause is considered to be in the wire harness or connectors.





SHORT CIRCUIT
This could be due to a short circuit between the wire harness and the body ground or to a short inside the switch, etc.

HINT:When there is a short between the wire harness and body ground, check thoroughly whether the wire harness is caught in the body or is clamped properly.

VISUAL CHECK AND CONTACT PRESSURE CHECK
- Disconnect the connectors at both ends.





- Check for rust or foreign material, etc. on the terminals of the connectors.
- Check crimped portions for looseness or damage and check if the terminals are secured in the lock position.

HINT: The terminals should not come out when pulled lightly.





- Prepare a test male terminal and insert it in the female terminal, then pull it out.

NOTICE: When testing a gold-plated female terminal, always use a gold-plated male terminal.

HINT: When the test terminal is pulled out more easily than others, there may be poor contact in that section.

CONNECTOR HANDLING





When inserting tester probes into a connector, insert them from the rear of the connector. When necessary, use mini test leads. For water resistant connectors which cannot be accessed from behind, take good care not to deform the connector terminals.