COMPONENT LOCATION
GENERAL DESCRIPTION

The normal operating temperature of the HO2S(Heated Oxygen Sensor) ranges from 350 to 850℃(662 to 1562℉). The HO2S heater greatly decreases the amount of time required for fuel control to become active. The ECM provides a pulse width modulated control circuit to adjust current through the heater. When the HO2S is cold, the value of the resistance is low and the current in the circuit is high. On the contrary, if the temperature in the resistor of the sensor rises, the current drops gradually.

DTC DESCRIPTION

The ECM determines when a rear HO2S heater fault occurs and sets DTC P0036 if measured rear HO2S resistance is lower than the predetermined threshold.

DTC DETECTING CONDITION

Item

Detecting Condition

Possible Cause

DTC Strategy

●

Evaluate O2 sensor element temperature via measuring element resistance

●

Related fuse blown or missing

●

Heater control circuit open or short

●

Power supply circuit open or short

●

Contact resistance in connectors

●

Faulty HO2S

Enable Conditions

●

1% ＜ Heater power ＜ 99%

●

Time after start elapsed:240 sec.

●

11V ＜ Battery voltage ＜16V

●

Exhaust gas temp.model ＜ 650℃(1, 202℉)

●

Dewpoint exceeded

●

No relevant failure

Threshold Value

●

HO2S Element Resistance ＞ 1100 Ohm (Catalyst Temperature ＜ 500°C(932℉))

Diagnostic Time

●

5 min.

Mil On Condition

●

2 Driving Cycles

SIGNAL WAVEFORM AND DATA
SPECIFICATION

Temp.(℃)

Temp.(℉)

Heater Resistance (Ω)

18~20

64~82

Approx. 9

SCHEMATIC DIAGRAM
MONITOR DTC STATUS
1.

Connect scan tool and select "Diagnostic Trouble Codes(DTCs)" mode.

2.

Press F4(DTAL) to select DTC information from the DTCs menu.

3.

Confirm that "DTC Readiness Flag" indicates "Complete". If not, drive the vehicle within conditions noted in the freeze frame data or enable conditions.

4.

Read "DTC Status" parameter.

5.

Is parameter displayed "History(Not Present) fault"?

note
-

History (Not Present) fault : DTC occurred but has been cleared.

-

Present fault : DTC is occurring at present time.

▶ Fault is intermittent caused by poor contact in the sensor's and/or ECM's connector or was repaired and ECM memory was not cleared. Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage. Repair or replace as necessary and then go to "Verification of Vehicle Repair" procedure.

▶ Go to next step as below.

POWER CIRCUIT INSPECTION
1.

Ignition "OFF"

2.

Disconnect HO2S connector.

3.

Ignition "ON" ＆ Engine "OFF"

4.

Measure voltage between terminal 3 of the HO2S heater harness connector and chassis ground.

Specification : B+

5.

Is voltage within the specification?

▶ Go to "Control Circuit Inspection" procedure

▶ Check for an open in the power supply circuit between the main relay and the HO2S.

▶ Especially check for "SENSOR1 FUSE 10A" is installed and not blown.

▶ Repair or replace as necessary and go to "Verification of Vehicle Repair" procedure.

note

HO2S must have a clean air reference to function properly. The air is obtained by way of the sensor wire(s). Do not attempt to repair the wire(s), connector, or the terminals.

CONTROL CIRCUIT INSPECTION
1.

Measure voltage between terminal 4 of the HO2S heater harness connector and chassis ground.

Specification : Approx. 4~5V

2.

Is voltage within the specification?

▶ Go to next step as below.

▶ Repair or replace as necessary and go to "Verification of Vehicle Repair" procedure

note

HO2S must have a clean air reference to function properly. The air is obtained by way of the sensor wire(s). Do not attempt to repair the wire(s), connector, or the terminals.

TERMINAL AND CONNECTOR INSPECTION
1.

Many malfunctions in the electrical system are caused by poor harness(es) and terminals. Faults can also be caused by interference from other electrical systems, and mechanical or chemical damage.

2.

Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage.

3.

Has a problem been found?

▶ Repair as necessary and go to "Verification of Vehicle Repair" procedure.

▶ Go to next step as below

COMPONENT INSPECTION
1.

Ignition "OFF"

2.

Measure resistance between terminals 3 and 4 of the sensor connector (Component side).

Specification

Temp.(℃)

Temp.(℉)

Heater Resistance (Ω)

18~20

64~82

Approx. 9

3.

Is resistance within the specification?

▶ Check for poor connection between ECM and component: backed out terminal, improper mating, broken locks or poor terminal to wire connection. Repair as necessary and go to "Verification of Vehicle Repair" procedure.

▶ Check HO2S for contamination, deterioration, or damage. Substitute with a known-good HO2S and check for proper operation. If the problem is corrected, replace HO2S and then go to "Verification of Vehicle Repair" procedure.

VERIFICATION OF VEHICLE REPAIR

After a repair, it is essential to verify that the fault has been corrected.

1.

Connect scan tool and select "Diagnostic Trouble Codes(DTCs)" mode.

2.

Press F4(DTAL) and confirm that "DTC Readiness Flag" indicates "Complete". If not, drive the vehicle within conditions noted in the freeze frame data or enable conditions.

3.

Read "DTC Status" parameter.

4.

Is parameter displayed "History(Not Present) fault"?

▶ System performing to specification at this time. Clear the DTC

▶ Go to the applicable troubleshooting procedure.

Яндекс.Метрика