Explanation and Precaution Related to Harness Checking

- The connector symbol shown is as viewed from the terminal end of the connector inside the vehicle.
- "B+" used as the standard value in voltage check stands for system voltage.





- When checking a waterproof connector for circuit continuity, be sure to use the special tool, Test Harness. Never insert the test probe from the harness side as this causes loss of waterproof characteristics and corrosion may result. There are various test harnesses and the appropriate one for the connector being tested should be used.





- If the appropriate test harness for the particular connector is not available, the use of the Test Harness Set (MB991348) which can be connected directly between the terminals is recommended.
- When checking the terminal voltage with the connector disconnected, do not insert the test probe if the check terminal is female.
If the test probe is forced into the terminal, poor contact may be caused.





- When checking an open circuit of a wire with its ends physically separated, ground one end using a jumper wire and check the continuity between the other end and ground. Repair the wire if there is no continuity.





- When checking short-circuit to ground of a wire, open one end of the wire and check continuity between the other end and ground. If there is continuity, the wire is short-circuited to ground and requires repair.
- For checking continuity, use an analog ohmmeter (or circuit tester) as a rule.





- If the sensor impressed voltage is abnormal, check the wire for an open circuit or short-circuit to ground and repair as necessary. If the wire is normal, replace the engine control module and check again.
- To check the voltage, use a digital voltmeter (or circuit tester) as a rule.
[However, use an analog voltmeter for checking the power transistor drive voltage.]