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Monday, August 30, 2010

How to repair engine stalling and poor acceleration specially when the engine getting hot

How to repair engine stalling end poor accelerationspecially when the engine getting hot

 

Model:Hyundai Accent(MC)

Year Model: 2009

Fuel: Gasoline

Displacement: 1400cc

1) Subject:

  • Engine stalling and poor acceleration specially when engine getting hot.

2) Cause

  • Oxygen Sensor

3) Diagnosis

  1. Scan tool check
    =P0031 HO2S Heater Circuit Low (Sensor1)
     

Study Component Location

Study General Description

Study In order to control emissions of the CO, HC and NOx components of the exhaust gas, heated oxygen sensor (HO2S), mounted on the front side and rear side of catalytic converter, detects the oxygen content in the exhaust gas. Study The front HO2S signal is used to control air/fuel ratio (closed loop fuel control) and the rear HO2S signal is used to monitor front HO2S and catalyst for proper operation.

Study The HO2S requires a minimum temperature to operate properly and provide a closed loop fuel control system. The HO2S contains the heater element to reduce its warming-up time and ensure its performance during all driving conditions.

Study The ECM controls this heater element by duty cycle. The main relay supplies voltage to the heater and the ECM provides a ground circuit for activating the heater.

Study DTC Description

Study When ECM detects open or short to ground in the heater control circuit(B1S1), ECM sets DTC P0031.

Study DTC Detecting Condition

Item
Study Detecting Condition
Possible Cause

Study DTC Strategy
● Heater check low
● Poor connection
● Open or short to ground in power circuit
● Open or short to ground in control circuit
● B1S1
● ECM

Study Enable Conditions

Study Threshold Value
● Open or short to ground

Study Diagnostic Time
● Continuous

Study MIL ON Condition
● 2 driving cycle

※ B1S1 : upstream oxygen sensor / B1S2 : downstream oxygen sensor

Study Specification

ITEM
Specification

Heater Resistance(Ω)
Approx. 9.0Ω(20°C)

Study Terminal and Connector Inspection

1.Study Many malfunctions in the electrical system are caused by poor harness and terminals.

Faults can also be caused by interference from other electrical systems, and mechanical or chemical damage.

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

3.Study Has a problem been found?

YES

1)Study Repair as necessary and go to "Verification of Vehicle Repair" procedure.

NO

1)Study Go to " Power Circuit Inspection " procedure.

Power Supply Circuit Inspection

1.IG "OFF".

2.Study Disconnect HO2S(S1) connector.

3.IG "ON" & ENG "OFF"

4.Study Measure voltage between terminal 4 of HO2S(S1) harness connector and chassis ground.

A.Specification : B+

5.Is the measured voltage within specification ?

YES

1)Go to "Control Circuit Inspection" procedure.

 

NO

1)Study Repair or replace as necessary and then, go to "Verification of Vehicle Repair" procedue.

Control Circuit Inspection

1.IG "OFF".

2.Study Disconnect HO2S(S1) connector.

3.IG "ON" & ENG "OFF"

4.Study Measure voltage between terminal 3 of HO2S(S1) harness connector and chassis ground.

A.Specification : Approx. 3.5V

5.Is the measured voltage within specification ?

 

YES

1)Go to "Component Inspection" procedure.

 

NO

1)Study Repair or replace as necessary and then, go to "Verification of Vehicle Repair"procedure.

MORE STUDY AND PLEASE TRY TO LEAVE ME COMMENTS

 

Study,Study,Study,Study,Study,Study,Study,Study,Study,Study,Study,Study,Study

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