13107527-13107508-13107635-13107654-13107562-13107492-13107543-13107601-13107586-13107616

COMPONENT LOCATION

GENERAL DESCRIPTION

The rear heated oxygen sensor is mounted on the rear side of the Catalytic Converter (warm-up catalytic converter) or in the rear exhaust pipe, which is able to detect catalyst efficiency. The rear heated oxygen sensor (HO2S) produces a voltage between 0V and 1V. This rear heated oxygen sensor is used to estimate the oxygen storage capability. If a catalyst has good conversion properties, the oxygen fluctuations are smoothed by the oxygen storage capacity of the catalyst. If the conversion provided by the catalyst is low due to aging, poisoning or misfiring, then the oxygen fluctuations are similar to signals from the front oxygen sensor.

DTC DESCRIPTION

ECM sets DTC P0137 if the HO2S(B1S2) voltage remains excessively low for a predetermined time

DTC DETECTING CONDITION

Item	Detecting Condition	Possible Cause
DTC Strategy	● Voltage range check	● Short to ground in signal harness ● Contact resistance in connectors ● Faulty Heated O2 Sensor(HO2S)
Enable Conditions	● Catalyst temperature model ＞ 500℃( 932℉) ● Lambda regulation active ● Catalyst purge after fuel cut off is not active ● No relevant failure ● 10V ＜ Battery voltage ＜ 16V
Threshold Value	● Downstream O2 Sensor voltage ＜ 0.02V ＆ sensor element resistance ＜ 30Ω
Diagnostic Time	● 20 sec.
MIL On Condition	● 2 Driving Cycles

SIGNAL WAVEFORM AND DATA

Test Condition		Scan Tool Parameter
Test Condition		O2 SNSR VOL.-B1/S1	O2 SNSR VOL.-B1/S2
Normal Value when circuit is normal	Idle after warm up	Signal is switching from rich(above 0.45V) to lean(below 0.45V) a minimum of 3 times in 10 seconds.	above 0.7V
HO2S(B1S1) signal circuit open		Approx. 0.43~0.45V	-
HO2S(B1S2) signal circuit open		-	Approx. 0.43~0.45V

SCHEMATIC DIAGRAM

MONITOR DTC STATUS

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"?

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.

SIGNAL CIRCUIT INSPECTION

Ignition "OFF"

Disconnect ECM and HO2S connector

Measure resistance between terminal 2 of the sensor harness connector and chassis ground

Specification : Infinite

Is resistance 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

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 next step as below

COMPONENT INSPECTION

With ignition "OFF", reconnect the HO2S connector

Warm up the engine to normal operating temperature and let it idle.

Connect Scantool and monitor the O2 SNSR VOL.-B1/S2 parameter on the Scantool data list.

Specification : Above 0.7V at idle

Is sensor data near the specified value?

▶ 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.

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.