4.
Read "DTC Status" parameter
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 PCM 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.
The PCM determines when a rear HO2S heater fault occurs and sets DTC P0036 if measured rear HO2S resistance is lower than the predetermined threshold.
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 | ● Sensor preheating and full heating phases finished ● Time after start elapsed:240 sec. ● 11V＜Battery voltage＜16V ● 1%＜Heater power＜99% ● Exhaust gas temp. model＜650°C (1,202°F) | |
Threshold Value | ● O2 sensor Element Resistance ＞1100 Ohm | |
Diagnostic Time | ● 5 min. | |
Fail-Safe | ● EVAP. emission control function is controlled in minimum operation mode |
Temp.(℃) | Temp.(℉) | Rear HO2S Heater Resistance(Ω) | Temp.(℃) | Temp.(℉) | Rear HO2S Heater Resistance(Ω) |
20 | 68 | 9.2 | 500 | 932 | 19.2 |
100 | 212 | 10.7 | 600 | 1,112 | 20.7 |
200 | 392 | 13.1 | 700 | 1,292 | 22.5 |
300 | 572 | 14.6 | 800 | 1,472 | 25.1 |
400 | 752 | 17.7 | 900 | 1,652 | 26.5 |
Connect scan tool and select "Diagnostic Trouble Codes(DTCs)" mode
Press F4(DTAL) to select DTC information from the DTCs menu
Confirm that "DTC Readiness Flag" indicates "Complete". If not, drive the vehicle within conditions noted in the freeze frame data or enable conditions
Read "DTC Status" parameter
Is parameter displayed "History(Not Present) fault"?
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 PCM's connector or was repaired and PCM memory was not cleared. Thoroughly check connectors for loose or poor connection, bending, corrosion, contamination, deterioration, or damage. Repair or replace as necessary and go to "Verification of Vehicle Repair" procedure.
▶ Go to next step as below.
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.
Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage.
Has a problem been found?
▶ Repair as necessary and go to "Verification of Vehicle Repair" procedure
▶ Go to "Power Supply Circuit Inspection" procedure.
Ignition "OFF".
Disconnect HO2S sensor connecto.
Ignition "ON" & Engine "OFF"
Measure voltage between terminal 3 of the HO2S heater harness connector and chassis ground.
Specification : Approx. B+
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 "10A Sensor fuse" is installed and not blown.
Repair as necessary and go to "Verification of Vehicle Repair" procedure.
Check for open in control harness.
Ignition "OFF".
Disconnect PCM connector
Measure resistance between terminals 4 of the HO2S heater harness connector and 9 of the PCM harness connector.
Specification : Approx 0Ω
Is resistance within the specification?
▶ Go to next step as below
▶ Repair as necessary and go to "Verification of Vehicle Repair" procedure.
Check for short to ground in control circuit.
Measure resistance between terminal 4 of the HO2S heater harness connector and chassis ground.
Specification : infinite
Is resistance within the specification?
▶ Go to next step as below
▶ Repair as necessary and go to "Verification of Vehicle Repair" procedure.
Check for short to power in control circuit.
Reconnect the PCM connector.
Ignition "ON" & Engine "OFF"
Measure voltage between terminal 4 of the HO2S heater harness connector and chassis ground
Specification : Approx 0V
Is voltage within the specification?
▶ Go to "Component Inspection" procedure.
▶ Repair open or short to ground in control circuit and go to "Verification of Vehicle Repair" procedure
Ignition "OFF".
Measure resistance between terminals 3 and 4 of the sensor connector (Component side)
Temp.(℃) | Temp.(℉) | Rear HO2S Heater Resistance(Ω) | Temp.(℃) | Temp.(℉) | Rear HO2S Heater Resistance(Ω) |
20 | 68 | 9.2 | 500 | 932 | 19.2 |
100 | 212 | 10.7 | 600 | 1,112 | 20.7 |
200 | 392 | 13.1 | 700 | 1,292 | 22.5 |
300 | 572 | 14.6 | 800 | 1,472 | 25.1 |
400 | 752 | 17.7 | 900 | 1,652 | 26.5 |
Is resistance within the specification?
▶ Check for poor connection between PCM 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.
After a repair, it is essential to verify that the fault has been corrected.
Connect scan tool and select "Diagnostic Trouble Codes(DTCs)" mode
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.
Read "DTC Status" parameter
Is parameter displayed "History(Not Present) fault"?
▶ System performing to specification at this time. Clear the DTC
▶ Go to the applicable troubleshooting procedure.
