ENGINE (DIAGNOSTICS)(H4DOTC) > Diagnostic Procedure with Diagnostic Trouble Code (DTC)

DTC P0418 SECONDARY AIR INJECTION SYSTEM CONTROL “A” CIRCUIT

DTC DETECTING CONDITION:

Immediately at fault recognition

CAUTION:

After repairing or replacing the defective part, perform the Clear Memory Mode and Inspection Mode .

WIRING DIAGRAM:

• LHD model

• RHD model

STEPCHECKYESNO

1.CHECK HARNESS BETWEEN ECM AND SECONDARY AIR PUMP RELAY.

1) Turn the ignition switch to OFF.

2) Disconnect the connectors from the ECM.

3) Remove the secondary air pump relay from the relay box.

4) Measure the resistance of the harness between the ECM and secondary air pump relay terminal.

Connector & terminal

(B136) No. 8 — (F9) No. 6:

Is the resistance less than 1 Ω?

Repair open circuit of the harness between the ECM and secondary air pump relay terminal.

2.CHECK HARNESS BETWEEN ECM AND SECONDARY AIR PUMP RELAY.

Measure the resistance of harness between ECM and chassis ground.

Connector & terminal

(B136) No. 8 — Chassis ground:

Is the resistance 1 MΩ or more?

Temporary poor contact occurs. Check the poor contact of connector.

Repair ground short of the harness between the ECM and secondary air pump relay terminal.