Diagnostic Procedure

WARNING: This page is about a different variant/trim than selected.

DTC P0030 DIAGNOSTIC PROCEDURE

STEP

INSPECTION

ACTION

VERIFY FREEZE FRAME DATA AND DIAGNOSTIC MONITORING TEST RESULTS HAVE BEEN RECORDED

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

Yes

Go to the next step.

Record the FREEZE FRAME DATA and DIAGNOSTIC MONITORING TEST RESULTS on the repair order, then go to the next step.

VERIFY RELATED REPAIR INFORMATION AVAILABILITY

Verify related Service Information availability.
Is any related Service Information available?

Yes

Perform repair or diagnosis according to the available Service information.
If the vehicle is not repaired, go to the next step.

Go to the next step.

VERIFY RELATED PENDING CODE OR STORED DTC

Turn the ignition switch off, then to the ON position (Engine off).
Verify the related PENDING CODE or stored DTCs using the WDS or equivalent.
Is the DTC P0031 or P0032 also present?

Yes

Go to appropriate DTC troubleshooting procedure.
(See DTC TABLE ).

Go to the next step.

IDENTIFY TRIGGER DTC FOR FREEZE FRAME DATA

Is DTC P0030 on FREEZE FRAME DATA?

Yes

Go to the next step.

Go to troubleshooting for DTC on FREEZE FRAME DATA.
(See DTC TABLE ).

INSPECT FRONT HO2S CONNECTOR FOR POOR CONNECTION

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 11.

Go to the next step.

INSPECT FRONT HO2S HEATER CONTROL CIRCUIT FOR SHORT TO GROUND

Front HO2S connector disconnected.
Inspect for poor connection (such as damaged/pulled-out pins, and corrosion).
Is there continuity?

Yes

Repair or replace for short to ground, then go to Step 11.

Go to the next step.

INSPECT FRONT HO2S HEATER

Inspect the front HO2S heater.
(See HEATED OXYGEN SENSOR (HO2S) INSPECTION ).
Is there any malfunction?

Yes

Replace the front HO2S, then go to Step 11.
(See EXHAUST SYSTEM REMOVAL/INSTALLATION ).
(See EXHAUST SYSTEM REMOVAL/INSTALLATION ).

Go to the next step.

INSPECT PCM CONNECTOR FOR POOR CONNECTION

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 Step 11.

Go to the next step.

INSPECT FRONT HO2S CIRCUIT FOR OPEN

Front HO2S and PCM connectors disconnected.
Measure the continuity following circuit at wiring harness-side terminal.
- Between front HO2S terminal C⁽¹⁾, 2D⁽²⁾ and PCM terminal 2BG
- Between front HO2S terminal 1B⁽²⁾ and PCM terminal 2AC⁽²⁾
Are there continuity?

Yes

Go to the next step.

Repair or replace for open, then go to Step 11.

INSPECT FRONT HO2S HEATER CONTROL CIRCUIT FOR SHORT TO POWER

Front HO2S and PCM connectors disconnected.
Measure the voltage between front HO2S sensor terminal C⁽¹⁾, 2D⁽²⁾ (wiring harness-side) and ground?
Is the voltage greater than 1.5V

Yes

Repair or replace for short to power, then go to the next step.

Go to the next step.

VERIFY TROUBLESHOOTING OF DTC P0030 COMPLETED

Make sure to reconnect all disconnected connectors.
Clear the DTC from the PCM memory using the WDS or equivalent.
Perform the KOEO or KOER self-test.
(See KOEO/KOER SELF TEST ).
Is the PENDING CODE for this DTC present?

Yes

Replace the PCM, then go to the next step.
(See PCM REMOVAL/INSTALLATION ).

Go to the next step.

VERIFY AFTER REPAIR PROCEDURE

Perform the "AFTER REPAIR PROCEDURE".
(See AFTER REPAIR PROCEDURE ).
Are any DTCs present?

Yes

Go to the applicable DTC inspection.
(See DTC TABLE ).

DTC troubleshooting completed.

⁽¹⁾	California Emission Regulation Applicable ATX Model

⁽²⁾	Except for California Emission Regulation Applicable ATX Model