P2195
DTC P2195
GENERAL DESCRIPTION
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. 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.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.The oxygen sensor generates a voltage that indicates the difference between the oxygen content of the exhaust stream and the oxygen content of ambient air. When the exhaust stream is rich, there is more oxygen in the ambient air than in the exhaust stream, so the voltage will be higher.
DTC DESCRIPTION
Checking output signals from HO2S under detecting condition, if an output signal within the detecting condition lasts continuously, PCM sets P2195. MIL(Malfunction Indication Lamp) turns on when the malfunction lasts till consecutive 2 driving cycle.
DTC Detecting Condition:
DTC DETECTING CONDITION
Specification:
SPECIFICATION
Schematic Diagram:
SCHEMATIC DIAGRAM
Signal Wavefrom And Data:
SIGNAL WAVEFORM AND DATA
After warming-up, if accelerator pedal is released suddenly around 4000 rpm, the HO2S signal reading will be lower than 200 mV resulting from Fuel cut-off for the moment. Conversely, if suddenly accelerator pedal is depressed, HO2S signal reading will be around 0.6V - 1.0 V. At idle, HO2S signal will switch from lean to rich normally.
MONITOR SCANTOOL DATA
1. Connect Scantool to DLC (Data Link Connector)
2. Warm up the engine to normal operating temperature.
3. Monitor "HO2S(B1S1)" parameter on Scantool
Specification : 0.1 - 0.9 V
4. Does the "HO2S(B1S1)" parameter operates correctly?
YES - Fault is intermittent caused by poor contact in 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 go to "Verification of Vehicle Repair" procedure
NO - Go to "Component Inspection" procedure.
COMPONENT INSPECTION
1. Visual Inspection
a. Visually check HO2S as follow.
- Contamination, deformation or age of HO2S(B1/S1)
b. Is the HO2S(B1/S1) normal?
YES - Go to "Check performance of HO2S" as follows.
NO - Substitute with a known-good HO2S(B1S1) and check for proper operation. If the problem is corrected,replace HO2S(B1S1) and then go to "Verification of Vehicle Repair" procedure.
2. Check performance of HO2S
a. Connect Scantool to DLC (Data Link Connector)
b. Warm up the engine to normal operating temperature.
c. Monitor signal waveform of HO2S with Scantool.
Specification : 0.1 - 0.9 V.
d. Is the HO2S(B1S1) working properly?
YES - Substitute with a known-good PCM and check for proper operation. If the problem is corrected,replace PCM and then go to "Verification of Vehicle Repair" procedure.
NOTE: There is a memory reset function on Scantool that can erase optional parts automatically detected and memorized by PCM.
NO - Substitute with a known-good HO2S(B1S1) and check for proper operation. If the problem is corrected,replace HO2S(B1S1) 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.
1. Monitor and record the Freeze Frame Data for the Diagnostic Trouble Code(DTC) which has been diagnosed.
2. Using a Scantool, Clear the DTCs
3. Operate the vehicle within conditions noted in the freeze frame data or enable conditions
4. Monitor that all readiness test have been verified as "Complete".
5. Are any DTCs present?
YES - Go to the applicable troubleshooting procedure.
NO - System is performing to specification at this time.