CHECK HARNESS BETWEEN MAIN FAN RELAY 1 AND ECM.

1) Disconnect the connector from ECM.

2) Measure the resistance between the main fan relay 1 terminal and ECM connector.

Connector & terminal

Euro 4 model

(B135) No. 27 — (B143) No. 7:

Euro 5 model

(B134) No. 32 — (B143) No. 7:

QUESTION

Is the resistance less than 1 Ω?

Yes No

Repair the open circuit of the harness between main fan relay 1 terminal and ECM.