P0050
DTC P0050 HO2S HEATER CONTROL CIRCUIT (BANK 2 / SENSOR 1)Component Location:
GENERAL DESCRIPTION
The normal operating temperature of the HO2S (Heated Oxygen Sensor) ranges from 350 to 850 degrees C (662 to 1562 degrees F). The HO2S heater greatly decreases the amount of time required for fuel control to become active. The ECM provides a pulse width modulated control circuit to adjust current through the heater. When the HO2S is cold, the value of the resistance is low and the current in the circuit is high. On the contrary, if the temperature in the resistor of the sensor rises, the current drops gradually.
DTC DESCRIPTION
Checking current from HO2S under detecting condition,if the heater current is below a certain threshold for more than predetermination, PCM sets P0050. MIL (malfunction Indication Lamp) turns on when the malfunction lasts till consecutive 2 driving cycle.
DTC Detecting Condition:
SPECIFICATION
(REFERENCE ONLY)
Condition Current
Heater Current at 13.5 V. 450 degrees C (842 degrees F) Exhaust 0.25 ± 0.1
Schematic Diagram:
Signal Waveform And Data:
SIGNAL WAVEFORM AND DATA
The HO2S requires a minimum temperature to provide a closed loop fuel control system. So the HO2S contains a heater element to reduce its warm-up time and ensure its performance during all driving conditions. The PCM controls this heater element by duty cycle. The main relay supplies voltage to the heater and the PCM provides a ground circuit for activating the heater.
MONITOR DTC STATUS
1. Check DTC Status
1. Connect scantool to Data Link Connector (DLC).
2. IG "ON".
3. Select "Diagnostic Trouble Codes (DTCs)" mode, and then Press F4 (DTAL) to check DTC's information from the DTCs menu
4. Read "DTC Status" parameter.
5. Is parameter displayed "Present fault"?
YES - Go to "Terminal and connector inspection" procedure.
NO - 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, ending, corrosion, contamination, deterioration, or damage. Repair or replace 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 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 - Go to "Component Inspection" procedure.
COMPONENT INSPECTION
1. Check HO2S (B2/S1) Heater resistance
1. IG "OFF" and disconnect HO2S (B2/S1) connector
2. Measure resistance between terminal 1 and 2 of HO2S (B2/S1) (Component Side)
Specification : 3.0 - 4.09 [21 degrees C (69.8 degrees F)]
3. Is the measured resistance within specification?
YES
- Substitute with a known - good PCM and check for proper operation.
- If the problem is corrected, 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. Before or after testing PCM on the vehicle, use this function to reuse the PCM on the others
NO
- Substitute with a known - good HO2S (B2/S1) and check for proper operation.
- If the problem is corrected, 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.