Diagnosis Procedure

WARNING: This page is about a different car, the 2010 Nissan Sentra. However, it is still accessible from the selected car via links, so may be relevant.

CHECK CONNECTOR
1. Turn the ignition switch OFF.
2. Disconnect the battery cable from the negative terminal.
3. Check the following terminals and connectors for damage, bend and loose connection (unit side and connector side).
  - ECM
  - Harness connector E4 (M/T models without ABS)
  - Harness connector M2 (M/T models without ABS)
    Is the inspection result normal?
    
    YES: GO TO 2.
    
    NO: Repair the terminal and connector.

CHECK HARNESS FOR OPEN CIRCUIT

Disconnect the connector of ECM.

Check the resistance between the ECM harness connector terminals.

MR20DE

CONNECTOR TERMINAL RESISTANCE CHART

ECM harness connector			Resistance (Ω)
Connector No.	Terminal No.		Resistance (Ω)
E16	84	83	Approx. 108 - 132

QR25DE

CONNECTOR TERMINAL RESISTANCE CHART

ECM harness connector			Resistance (Ω)
Connector No.	Terminal No.		Resistance (Ω)
E16	98	97	Approx. 108 - 132

Is the measurement value within the specification?

YES: GO TO 3.

NO: Repair the ECM branch line.

CHECK POWER SUPPLY AND GROUND CIRCUIT
Check the power supply and the ground circuit of the ECM. Refer to the following.
- MR20DE (For California): "DIAGNOSIS PROCEDURE "
- MR20DE (Except for California): "DIAGNOSIS PROCEDURE "
- QR25DE: "DIAGNOSIS PROCEDURE "
  Is the inspection result normal?
  
  YES (Present error): Replace the ECM. Refer to the following.
  - MR20DE (For California): "PROCEDURE AFTER REPLACING ECM "
  - MR20DE (Except for California): "PROCEDURE AFTER REPLACING ECM "
  - QR25DE: "PROCEDURE AFTER REPLACING ECM "
  YES (Past error): Error was detected in the ECM branch line.
  
  NO: Repair the power supply and the ground circuit.