DTC P0038:00

HO2S heater control circuit high input

DETECTION CONDITION

• When the PCM controls the HO2S heater, the voltage input to the PCM is too high.

Diagnostic support note

• This is a continuous monitor (A/F sensor heater, HO2S heater).

• The check engine light illuminates if the PCM detects the above malfunction condition in two consecutive drive cycles or in one drive cycle while the DTC for the same malfunction has been stored in the PCM.

• PENDING CODE is available if the PCM detects the above malfunction condition during first drive cycle.

• FREEZE FRAME DATA/Snapshot data is available.

• DTC is stored in the PCM memory.

FAIL-SAFE FUNCTION

• Stops fuel feedback control

POSSIBLE CAUSE

• HO2S connector or terminals malfunction

• PCM connector or terminals malfunction

• Short to power supply in wiring harness between HO2S terminal D and PCM terminal 2C

• HO2S heater malfunction

• PCM malfunction

STEP

INSPECTION

ACTION

1

NOTE:

• Recording can be facilitated using the screen capture function of the PC.

• Record the FREEZE FRAME DATA/snapshot data and DIAGNOSTIC MONITORING TEST RESULTS (A/F sensor heater, HO2S heater related) on the repair order.

—

Go to the next step.

2

• Verify related Service Bulletins and/or on-line repair information availability.

• Is any related repair information available?

Yes

Perform repair or diagnosis according to the available repair information.

• If the vehicle is not repaired, go to the next step.

No

Go to the next step.

3

• Switch the ignition off.

• Disconnect the HO2S connector.

• Inspect for poor connection (such as damaged/pulled-out pins, corrosion).

• Is there any malfunction?

Yes

Repair or replace the connector and/or terminals, then go to Step 7.

No

Go to the next step.

4

• Disconnect the PCM connector.

• Inspect for poor connection (such as damaged/pulled-out pins, corrosion).

• Is there any malfunction?

Yes

Repair or replace the connector and/or terminals, then go to Step 7.

No

Go to the next step.

5

• Verify that the HO2S and PCM connectors are disconnected.

• Switch the ignition ON (engine off).

  NOTE:

  • Another DTC may be stored by the PCM detecting an open circuit.

• Measure the voltage at the HO2S terminal D (wiring harness-side).

• Is the voltage 0 V?

Yes

Go to the next step.

No

Refer to the wiring diagram and verify whether or not there is a common connector between HO2S terminal D and PCM terminal 2C.

If there is a common connector:

• Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for a short to power supply.

• Repair or replace the malfunctioning part.

If there is no common connector:

• Repair or replace the wiring harness which has a short to power supply.

Go to Step 7.

6

• Inspect the HO2S heater.

  (See HEATED OXYGEN SENSOR (HO2S) INSPECTION [SKYACTIV-G 2.0].)

• Is there any malfunction?

Yes

Replace the HO2S, then go to the next step.

(See HEATED OXYGEN SENSOR (HO2S) REMOVAL/INSTALLATION [SKYACTIV-G 2.0].)

No

Go to the next step.

7

• Always reconnect all disconnected connectors.

• Clear the DTC from the PCM memory using the M-MDS.

  (See AFTER REPAIR PROCEDURE [PCM (SKYACTIV-G 2.0)].)

• Perform the KOER self test.

  (See KOEO/KOER SELF TEST [PCM (SKYACTIV-G 2.0)].)

• Is the PENDING CODE for this DTC present?

Yes

Repeat the inspection from Step 1.

• If the malfunction recurs, replace the PCM.

  (See PCM REMOVAL/INSTALLATION [SKYACTIV-G 2.0].)

Go to the next step.

No

Go to the next step.

8

• Perform the “AFTER REPAIR PROCEDURE”.

  (See AFTER REPAIR PROCEDURE [PCM (SKYACTIV-G 2.0)].)

• Are any DTCs present?

Yes

Go to the applicable DTC inspection.

(See DTC TABLE [PCM (SKYACTIV-G 2.0)].)

No

DTC troubleshooting completed.