DTC P0030

Front HO2S heater control circuit problem

DETECTION CONDITION

• The PCM monitors the front HO2S impedance when under the front HO2S heater control for 200 s. If the impedance is more than 44 ohms, the PCM determines that there is a front HO2S heater control circuit problem.

Diagnostic support note

• This is an intermittent monitor (HO2S heater).

• The MIL 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 the first drive cycle.

• FREEZE FRAME DATA is available.

• The DTC is stored in the PCM memory.

POSSIBLE CAUSE

• Front HO2S heater malfunction

• Connector or terminal malfunction

• PCM malfunction

STEP

INSPECTION

ACTION

1

• Have FREEZE FRAME DATA and DIAGNOSTIC MONITORING TEST RESULTS (HO2S heater related) been recorded?

Yes

Go to the next step.

No

Record the FREEZE FRAME DATA and DIAGNOSTIC MONITORING TEST RESULTS on the repair order, then 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

• Turn the ignition switch off, then to the ON position (Engine off).

• Verify the related PENDING CODE or stored DTCs.

• Are other DTCs present?

Yes

Go to the appropriate DTC inspection.

(See DTC TABLE [LF].)

No

Go to the next step.

4

• Turn the ignition switch off.

• Disconnect the front HO2S connector.

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

• Is there any malfunction?

Yes

Repair or replace the terminal, then go to Step 7.

No

Go to the next step.

5

• Inspect the front HO2S heater.

  (See FRONT HEATED OXYGEN SENSOR (HO2S) INSPECTION [LF].)

• Is there any malfunction?

Yes

Replace the front HO2S, then go to Step 7.

(See FRONT HEATED OXYGEN SENSOR (HO2S) REMOVAL/INSTALLATION [LF].)

No

Go to the next step.

6

• Turn the ignition switch off.

• Disconnect the PCM connector.

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

• Is there any malfunction?

Yes

Repair or replace the terminal, then go to the next step.

No

Go to the next step.

7

• Make sure to reconnect all disconnected connectors.

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

• Perform the KOEO self-test (using M-MDS) or the HO2S heater, HO2S, and TWC Repair Verification Drive Mode (not using M-MDS).

  (See KOEO/KOER SELF TEST [LF].)

  (See OBD-II DRIVE MODE [LF].)

• Is the PENDING CODE for this DTC present?

Yes

Replace the PCM, then go to the next step.

(See PCM REMOVAL/INSTALLATION [LF].)

No

Go to the next step.

8

• Perform the “AFTER REPAIR PROCEDURE”.

  (See AFTER REPAIR PROCEDURE [LF].)

• Are any DTCs present?

Yes

Go to the applicable DTC inspection.

(See DTC TABLE [LF].)

No

DTC troubleshooting completed.