Nissan Sentra Service Manual: Ecm branch line circuit

Diagnosis procedure

1.Check connector

1. Turn the ignition switch OFF.
2. Disconnect the battery cable from the negative terminal.
3. Check the terminals and connectors of the ECM for damage, bend and loose connection (unit side and connector side).

Is the inspection result normal? Yes >> go to 2.

No >> repair the terminal and connector.

2.Check harness for open circuit

1. Disconnect the connector of ecm.
2. Check the resistance between the ecm harness connector terminals.

Is the measurement value within the specification? Yes >> go to 3.

No >> repair the ecm branch line.

3.Check power supply and ground circuit

Check the power supply and the ground circuit of the ecm. Refer to ec-164, "diagnosis procedure".

Is the inspection result normal? Yes (present error)>>replace the ecm. Refer to ec-485, "removal and installation".

Yes (past error)>>error was detected in the ecm branch line.

No >> repair the power supply and the ground circuit.