331

If Main relay is not operated normally, possible causes are abnormal IG "ON" signal, ECM power, ECM ground and faulty ECM. If Main relay does not work normally, ECM is not operated. Therefore trouble shooting by using the scantool is impossible.

Inspect IGN#1 fusible link (40A) and ECU fuse (10A) on the U/H junction box.

Case 1 : In case that fuse and battery power is normal.

Go to "Next procedure" as below.

Case 2 :

In case that IGN#1 fusible link (40A) is blown.

- Repair short to ground in IGN#1 power supply circuit between U/H junction box connector (U/H-B) terminal "35" and ignition switch connector (M18) terminal "6".

- Repair short to ground in IGN#1 power supply circuit between ignition switch connector (M18) terminal "6" and U/H junction box connector (U/H-B) terminal "36".

In case that fuse 33 (10A) is blown.

- Repair short to ground in IGN#1 power supply circuit between U/H junction box connector (U/H-C) terminal "20" and ECM connector (C230-K) terminal "28".

- Repair short to ground in IGN#1 power supply circuit related with mass air flow sensor and vehicle speed sensor.

Inspect "IGN" power at terminal "28" after disconnecting ECM connector (C230-K).

caution

"ECM Connector Inspection" of "Details Inspection(Equipment Setting)" reference

IG "ON" : 11.5V~13.0V

IG "OFF" : Below 0.2V

Case 1 : In case that IG "ON" power at ECM connector (C230-K) terminal "28" is normal, When IG KEY is switched "ON" ↔ "OFF".

Go to "Main relay circuit inspection" procedure.

Case 2 : In case that IG "ON" power at ECM connector (C230-K) terminal "28" is abnormal, When IG KEY is switched "ON" ↔ "OFF".

Repair open in IGN#1 power supply circuit between U/H junction box connector (U/H-C) terminal "20" and ECM conector (C230-K) terminal "28".