ENGINE (DIAGNOSTICS)(H4SO) > Diagnostic Procedure with Diagnostic Trouble Code (DTC)

DTC P0038 HO2S HEATER CONTROL CIRCUIT HIGH (BANK 1 SENSOR 2)

DTC DETECTING CONDITION:

Detected when two consecutive driving cycles with fault occur.

CAUTION:

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

WIRING DIAGRAM:

STEPCHECKYESNO

1.CHECK HARNESS BETWEEN ECM AND REAR OXYGEN SENSOR.

1) Turn the ignition switch to OFF.

2) Measure the voltage between ECM and chassis ground.

Connector & terminal

(B136) No. 4 (+) — Chassis ground (−):

Is the voltage 10 V or more?

Repair the short circuit to power in the harness between ECM and rear oxygen sensor connector.

2.CHECK GROUND CIRCUIT FOR ECM.

1) Disconnect the connectors from the ECM.

2) Measure the resistance between ECM and chassis ground.

Connector & terminal

(B134) No. 5 — Chassis ground:

(B137) No. 1 — Chassis ground:

(B137) No. 2 — Chassis ground:

(B137) No. 3 — Chassis ground:

(B137) No. 7 — Chassis ground:

MT model

(B136) No. 15 — Chassis ground:

RHD model

(B136) No. 14 — Chassis ground:

Is the resistance less than 5 Ω?

Repair the poor contact of the ECM connector.

Repair the harness and connector.

NOTE:

In this case, repair the following item:

• Open circuit of harness between ECM and engine ground

• Poor contact of coupling connector