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 PCM monitors front HO2S tip temperature and signal at the same time to check open circuit of Pumping Current Trim Circuit (PCM PIN No. 41). The PCM sets DTC P2626 if front O2 tip temperature is lower than the predetermined threshold and if front HO2S signal after oscillator off is lower than the predetermined threshold. If the same error code is set in the next driving cycle, the PCM illuminates the MIL.
DTC Detecting Condition
MONITOR DTC STATUS
NOTE: If any DTCs relating to HO2S are present, DO ALL REPAIRS associated with those codes before proceeding with this troubleshooting tree.
Connect scan tool and select "Diagnostic Trouble Codes(DTCs)" mode
Press F5(INFO) 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.
YES - 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 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.
PUMPING CURRENT CIRCUIT INSPECTION
Ignition "OFF"
Disconnect HO2S and PCM connectors.
Measure resistance between terminals 1 of the sensor harness connector and 41 of the PCM harness connector
Specification : Approx. 0 Ohm
Is resistance within the specification?
YES - Go to "Terminal and Connector Inspection" procedure
NO - Repair as necessary and go to "Verification of Vehicle Repair" procedure
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?
YES - Repair as necessary and go to "Verification of Vehicle Repair" procedure
NO - 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
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 F5(INFO) 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"?
YES - System performing to specification at this time. Clear the DTC
NO - Go to the applicable troubleshooting procedure
Schematic Diagram
this is the chart for 2626
171 is a lean code most likley from a vacuum leak
Roy
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Tuesday, November 6th, 2012 AT 2:00 AM