DESCRIPTION

HO2S circuit no activity detected

DETECTION CONDITION

Determination conditions

• With the estimated temperature of the HO2S element exceeding the specified value, a condition in which the HO2S signal voltage is less than the specified value continues for the specified period.

Preconditions

• Battery voltage: above 11 V^*1

• The following DTCs are not detected:

• HO2S: P0137:00, P0138:00

• ECT sensor No.1: P0117:00, P0118:00

• MAF sensor: P0101:00, P0102:00, P0103:00

• ^*1: Value can be verified by displaying PIDs using M-MDS

Drive cycle

• 2

Self test type

• CMDTC self test

Sensor used

• HO2S

FAIL-SAFE FUNCTION

• Not applicable

VEHICLE STATUS WHEN DTCs ARE OUTPUT

• Illuminates check engine light.

POSSIBLE CAUSE

• HO2S signal line error

• HO2S connector or terminals malfunction

• PCM connector or terminals malfunction

• Short to ground in wiring harness between HO2S terminal A and PCM terminal 2AI

• Open circuit in wiring harness between HO2S terminal A and PCM terminal 2AI

• HO2S loose

• HO2S malfunction

• Exhaust gas leakage from exhaust system (between A/F sensor and HO2S)

• Insufficient engine compression

• HO2S heater malfunction

• PCM malfunction

Item

Definition

Unit

Condition/Specification

HTR12

HO2S heater operation status

Off/On

• Ignition switched ON (engine off): Off

• Idle (after warm up): On

HO2S heater control duty value

%

• Ignition switched ON (engine off): 0%

• Idle (after warm up): 29.41% (ECT is 91 °C {196 °F})

O2S12

HO2S voltage

V

• Idle (after warm up): 0???1.0 V (ECT is 91 °C {196 °F})

• Deceleration fuel cut (accelerator pedal released from engine speed of 4,000 rpm or more): Approx. 0 V (ECT is 92 °C {198 °F})

STEP

INSPECTION

RESULTS

ACTION

1

• 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.

2

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, HO2S related) on the repair order.

???

Go to the next step.

3

• Start the engine.

• Access the following PIDs using the M-MDS:

  (See ON-BOARD DIAGNOSTIC TEST [PCM (SKYACTIV-G 2.0)].)

• HTR12

• O2S12

• When the following parts are shaken, does the PID value include a PID item which has changed?

• HO2S

• PCM

Yes

Repair or replace the applicable connector parts.

Go to the troubleshooting procedure to perform the procedure from Step 10.

No

Go to the next step.

4

• Start the engine and idle it.

• Access the O2S12 PID using the M-MDS.

  (See ON-BOARD DIAGNOSTIC TEST [PCM (SKYACTIV-G 2.0)].)

• Is the O2S12 PID value normal?

  (See PCM INSPECTION [SKYACTIV-G 2.0].)

Yes

Go to the next step.

No

Go to the troubleshooting procedure to perform the procedure from Step 1.

5

• Start the engine and idle it.

• Access the HTR12 PID using the M-MDS.

  (See ON-BOARD DIAGNOSTIC TEST [PCM (SKYACTIV-G 2.0)].)

• Is the HTR12 PID value normal?

  (See PCM INSPECTION [SKYACTIV-G 2.0].)

Yes

Go to the troubleshooting procedure to perform the procedure from Step 1.

No

Go to the troubleshooting procedure to perform the procedure from Step 9.

STEP

INSPECTION

RESULTS

ACTION

1

• Switch the ignition off.

• Disconnect the HO2S connector.

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

• Is there any malfunction?

Yes

Replace the HO2S, then go to Step 10.

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

No

Go to the next step.

2

• Disconnect the PCM connector.

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

• Is there any malfunction?

Yes

Replace the PCM, then go to Step 10.

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

No

Go to the next step.

3

• Verify that the HO2S and PCM connectors are disconnected.

• Inspect for continuity between HO2S terminal A (wiring harness-side) and body ground.

• Is there continuity?

Yes

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

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 ground.

• Repair or replace the malfunctioning part.

If there is no common connector:

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

Go to Step 10.

No

Go to the next step.

4

• Verify that the HO2S and PCM connectors are disconnected.

• Inspect for continuity between HO2S terminal A (wiring harness-side) and PCM terminal 2AI (wiring harness-side).

• Is there continuity?

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 A and PCM terminal 2AI.

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 an open circuit.

• Repair or replace the malfunctioning part.

If there is no common connector:

• Repair or replace the wiring harness which has an open circuit.

Go to Step 10.

5

• Verify the installation condition of the HO2S (installation angle, tightening torque value).

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

• Is the HO2S installed securely?

Yes

Go to the next step.

No

Retighten the HO2S, then go to Step 10.

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

6

• Reconnect all disconnected connectors.

• Inspect the HO2S.

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

• Is there any malfunction?

Yes

Replace the HO2S, then go to Step 10.

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

No

Go to the next step.

7

• Verify the exhaust gas leakage from the exhaust system. (between A/F sensor and HO2S)

• Is there any malfunction?

Yes

Repair or replace the malfunctioning part according to the inspection results, then go to Step 10.

No

Go to the next step.

8

• Inspect the engine compression.

  (See COMPRESSION INSPECTION [SKYACTIV-G 2.0].)

• Are compression pressures within specification?

Yes

Go to the next step.

No

Replace or overhaul the engine, then go to Step 10.

9

• 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.

10

• Always reconnect all disconnected connectors.

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

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

• Implement the repeatability verification procedure.

  (See Repeatability Verification Procedure.)

• Perform the Pending Trouble Code Access Procedure.

  (See ON-BOARD DIAGNOSTIC 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.

11

• Is any other DTC or pending code stored?

Yes

Go to the applicable DTC inspection.

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

No

DTC troubleshooting completed.