P2626
DTC P2626 HO2S PUMPING CURRENT TRIM CIRCUIT/OPEN (BANK 1 / SENSOR 1)Component Location:
GENERAL DESCRIPTION
The linear O2 sensor is mounted on the front side of the Catalytic Converter (warm-up catalytic converter) or in the front exhaust pipe. It detects a wide range of air/fuel ratios in the exhaust gas from the rich to lean regions. This linear O2 sensor produces a current that corresponds to a specific air/fuel ratio. The PCM monitors this signal and determines whether the air/fuel mixture is rich or lean. The PCM constantly monitors the linear O2 sensor and increases or decreases the fuel injection duration using this signal. This is called closed-loop fuel control operation.
DTC DESCRIPTION
The ECM monitors front O2 sensor control circuit (VN) and sets DTC P2243 if front O2 sensor signal stuck is detected.
DTC Detecting Condition:
Schematic Diagram:
SIGNAL WAVEFORM AND DATA
1. Voltage in HO2S
Test Condition : Ignition ON, Engine OFF / HO2S disconnected
2. Scan Tool Data
MONITOR DTC STATUS
NOTE: If any codes relating to Rear HO2S or TWC (Three way Catalyst Converter) are stored, do ALL REPAIRS associated with those codes before proceeding with this troubleshooting tree.
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: OTC occurred but has been cleared.
- Present fault: OTC is occurring at present time.
YES - 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.
NO - Go to next step as below.
CONTROL CIRCUIT INSPECTION
1. Ignition "OFF"
2. Disconnect front HO2S harness connector.
3. Measure voltage between terminal 1 of the HO2S harness connector and chassis ground
Specification : Approx. 2 - 3 V
4. Measure resistance between terminals 1 and 1,2,3,5,6 of the HO2S harness connector
Specification : Infinite
5. Is the measured data within specification?
YES - Check for open or short circuit in HO2S harness connector. Refer to "Signal Waveform & Data" procedure in "General Information". Repair as necessary and go to "Verification of Vehicle Repair" procedure.
NO - Repair as necessary and go to "Verification of Vehicle Repair" procedure.
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?
YES - Repair as necessary and go to "Verification of Vehicle Repair" procedure.
NO - 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.
COMPONENT INSPECTION
HO2S INSPECTION
1. Visually/physically inspect the HO2S for the following conditions:
- Ensure that the HO2S is securely installed. (Pigtail and wiring harness not making contact with the exhaust pipe)
- Check for corrosion on terminals and terminal tension (at the HO2S and at the ECM)
- Front HO2S for silicon contamination. This contamination will be indicated by a white powdery coating on the portion of the sensor exposed to the exhaust stream and this will result in a but false (high) voltage signal
- Fuel, engine coolant or oil contamination
- Use of improper sealant
- If contamination is evident on the HO2S, Fix the source of the sensor contamination before replacing the sensor to prevent future contamination. Go to "Verification of Vehicle Repair" procedure.
2. Warm up the engine to normal operating temperature and let it idle.
3. Connect Scantool and monitor the "O2 SNSR VOL.-B1/S1" and "O2 SNSR VOL.-B1/S2" parameters on the Scantool data list.
Specification : Refer to "Signal Waveform & Data" in the "General Information" procedure
- Front HO2S (O2 SNSR VOL.-B1/S1) : Approx. 1.5 - 2.0 V with idle after warm up
Sensor voltage decrease during engine acceleration and increase during engine deceleration Approx. 3.0 - 4.0 V when fuel cut
- Rear HO2S (O2 SNSR VOL.-B1/S2) : Above 0.7 V at idle
4. Was a problem found in any of the above areas?
YES - Repair or replace as necessary and go to "Verification of Vehicle Repair" procedure.
NO - Thoroughly 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.
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"?
YES - System performing to specification at this time. Clear the DTC
NO - Go to the applicable troubleshooting procedure.