P0154
3UZ-FE ENGINE CONTROL SYSTEM: SFI SYSTEM: P0134,P0154: Oxygen Sensor Circuit No Activity Detected (Bank 1 Sensor 1)
P0154 - Oxygen Sensor Circuit No Activity Detected (Bank 2 Sensor 1)
DESCRIPTION
The heated oxygen sensor is used to monitor oxygen concentration in the exhaust gas. For optimum catalytic converter operation, the air-fuel mixture must be maintained near the ideal stoichiometric air-fuel ratio. The heated oxygen sensor output voltage changes suddenly in the vicinity of the stoichiometric air-fuel ratio. The ECM adjusts the fuel injection time so that the air-fuel ratio is nearly stoichiometric. The heated oxygen sensor generates a voltage between 0.1 and 0.9 V in response to the oxygen concentration in the exhaust gas.
If the oxygen concentration in the exhaust gas increases, the air-fuel ratio is called lean. The heated oxygen sensor voltage drops below 0.45 V, which informs the ECM of the lean condition.
If oxygen is not in the exhaust gas, the air-fuel ratio is called rich. The heated oxygen sensor voltage increases above 0.45 V, which informs the ECM of the rich condition.
HINT
The ECM provides a pulse width modulated control circuit to adjust current through the heater. The heated oxygen sensor heater circuit uses a relay on the +B side of the circuit.
HINT
Confirm the heated oxygen sensor (sensor 1) voltage. Enter the following menus: Powertrain / Engine / Data List / O2S B1S1 or O2S B2S1.
If the voltage is less than 0.1 V, the sensor circuit may be open or short.
MONITOR DESCRIPTION
The ECM uses the heated oxygen sensor to optimize the air-fuel mixture with closed loop fuel control. This control helps decrease exhaust emissions by providing the catalyst with a nearly stoichiometric mixture. The sensor detects the oxygen level in the exhaust gas and the ECM uses this data to control the air-fuel ratio. The sensor output voltage range is from 0.1 V to 0.9 V. If the signal voltage is less than 0.45 V, the air-fuel ratio is lean. If the signal voltage is more than 0.45 V, the air-fuel ratio is rich. If the sensor does not indicate rich at least once despite the conditions for the closed loop fuel control being met and the specified time period has passed, the ECM will conclude that the closed loop fuel control is malfunctioning. The ECM will illuminate the MIL and a DTC is set.
MONITOR STRATEGY
TYPICAL ENABLING CONDITIONS
TYPICAL MALFUNCTION THRESHOLDS
MONITOR RESULT
Refer to CHECKING MONITOR STATUS Mode 6 Data.
CONFIRMATION DRIVING PATTERN
- Connect the Techstream to the DLC3.
- Turn the ignition switch to ON.
- Turn the Techstream on.
- Clear DTCs (even if no DTCs are stored, perform the clear DTC operation).
- Turn the ignition switch off and wait for at least 30 seconds.
- Turn the ignition switch to ON and turn the Techstream on [A].
- Start the engine and warm it up until the engine coolant temperature reaches 70°C (158°F) or higher [B].
- Drive the vehicle at 60 km/h (38 mph) or more for 3 minutes or more.
CAUTION:
When performing the confirmation driving pattern, obey all speed limits and traffic laws.
- Enter the following menus: Powertrain / Engine / Trouble Codes [D].
- Read the pending DTCs.
HINT
- If a pending DTC is output, the system is malfunctioning.
- If a pending DTC is not output, perform the following procedure.
- Enter the following menus: Powertrain / Engine / Utility / All Readiness.
- Input the DTC: P0134 or P0154.
- Check the DTC judgment result.
HINT
If the judgment result shows INCOMPLETE or UNKNOWN, perform steps [C] through [D] again.
- If no pending DTC is output, perform a universal trip and check for permanent DTCs Reading and Clearing Diagnostic Trouble Codes.
HINT
- If a permanent DTC is output, the system is malfunctioning.
- If no permanent DTC is output, the system is normal.
WIRING DIAGRAM
INSEPCTION PROCEDURE
HINT
It is possible the malfunctioning area can be found using the Active Test Control the Injection Volume for A/F Sensor operation. The Active Test can determine if the heated oxygen sensor or other potential trouble areas are malfunctioning or not.
The injection volume can be switched to -12.5% (decrease) or +25% (increase) by the Active Test.
The Active Test procedure enables a technician to check and graph the output voltage of the heated oxygen sensors.
- Procedure:
- Connect the Techstream to the DLC3.
- Turn the ignition switch to ON.
- Warm up the engine by running the engine at 2,500 rpm for approximately 90 seconds.
- Enter the following menus: Powertrain / Engine / Active Test / Control the Injection Volume for A/F Sensor.
- Perform the Active Test while the engine is idling.
Standard:
The heated oxygen sensor reacts in accordance with the increase and decrease of injection volume:
+25% -> Rich output: More than 0.55 V
-12.5% -> Lean output: Less than 0.4 V
NOTICE:
The heated oxygen sensor (sensor 1) output has a few seconds of delay and the heated oxygen sensor (sensor 2) output has a maximum of 20 seconds of delay.
If the vehicle is short on fuel, the air-fuel ratio becomes lean and the DTCs will be recorded.
NOTICE:
Inspect the fuses for circuits related to this system before performing the following inspection procedure.
HINT
- Read freeze frame data using the Techstream. Freeze frame data records the engine conditions when a malfunction is detected. When troubleshooting, freeze frame data can help determine if the vehicle was running or stopped, if the engine was warmed up or not, if the air-fuel ratio was lean or rich, and other data from the time the malfunction occurred.
- Bank 1 refers to the bank that includes No. 1 cylinder.
- Bank 2 refers to the bank that does not include No. 1 cylinder.
- No. 1 cylinder is located in the front part of the engine, opposite the transmission.
- Sensor 1 refers to the sensor closest to the engine body.
PROCEDURE
1. CHECK OTHER DTC OUTPUT
(a) Connect the Techstream to the DLC3.
(b) Turn the ignition switch to ON.
(c) Turn the Techstream on.
(d) Enter the following menus: Powertrain / Engine / Trouble Codes.
(e) Read the DTCs.
Result:
B -- GO TO DTC CHART Diagnostic Trouble Code Descriptions
A -- Continue to next step.
2. READ VALUE USING TECHSTREAM (HEATED OXYGEN SENSOR (SENSOR 1) VOLTAGE)
(a) Connect the Techstream to the DLC3.
(b) Turn the ignition switch to ON.
(c) Turn the Techstream on.
(d) Enter the following menus: Powertrain / Engine / O2S B1S1 or O2S B2S1.
(e) Allow the engine to idle until the ECT reaches 40°C (104°F).
(f) Quickly depress the accelerator pedal 3 times until the engine RPM reaches 4,000 rpm. Then, read the heated oxygen sensor voltage.
Standard Voltage:
The heated oxygen sensor voltage is 0.45 V or more at least once.
OK -- PERFORM CONFIRMATION DRIVING PATTERN
NG -- Continue to next step.
3. CHECK CONNECTION PCV HOSE
OK:
PCV hose is connected correctly and is not damaged.
NG -- REPAIR OR REPLACE PCV HOSE
OK -- Continue to next step.
4. INSPECT HEATED OXYGEN SENSOR
(a) Disconnect the H9 and H10 sensor connectors.
(b) Measure the resistance of the sensor.
Standard Resistance:
NG -- REPLACE HEATED OXYGEN SENSOR
OK -- Continue to next step.
5. INSPECT EFI RELAY
(a) Remove the EFI relay from the engine room No. 2 relay block.
(b) Measure the resistance of the EFI relay.
Standard Resistance:
NG -- REPLACE EFI RELAY
OK -- Continue to next step.
6. CHECK HARNESS AND CONNECTOR (HEATED OXYGEN SENSOR (SENSOR 1) - ECM)
(a) Disconnect the H9 and H10 sensor connectors.
(b) Disconnect the E2 and E4 ECM connectors.
(c) Measure the resistance of the wire harness side connectors.
Standard Resistance:
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
7. CHECK AIR INDUCTION SYSTEM
(a) Check the air induction system for vacuum leaks.
OK:
There are no vacuum leaks in air induction system.
NG -- REPAIR OR REPLACE AIR INDUCTION SYSTEM
OK -- Continue to next step.
8. CHECK FUEL PRESSURE
(a) Check the fuel pressure Testing and Inspection.
NG -- REPAIR OR REPLACE FUEL SYSTEM
OK -- Continue to next step.
9. INSPECT FUEL INJECTOR
(a) Check the injector injection (whether fuel volume is high or low, and whether injection pattern is poor).
NG -- REPLACE FUEL INJECTOR Service and Repair
OK -- Continue to next step.
10. CHECK FOR EXHAUST GAS LEAKAGE
NG -- REPAIR OR REPLACE EXHAUST SYSTEM
OK -- REPLACE HEATED OXYGEN SENSOR
11. PERFORM CONFIRMATION DRIVING PATTERN
Refer to the confirmation driving pattern for P0134 and P0154.
NEXT -- Continue to next step.
12. READ OUTPUT DTC (DTC P0134 OR P0154 IS OUTPUT AGAIN)
(a) Connect the Techstream to the DLC3.
(b) Turn the ignition switch to ON.
(c) Turn the Techstream on.
(d) Enter the following menus: Powertrain / Engine / Trouble Codes.
(e) Read the DTCs.
Result:
B -- REPLACE ECM Service and Repair
A -- Continue to next step.
13. CONFIRM IF VEHICLE HAS RUN OUT OF FUEL
(a) If the vehicle has run out of fuel, proceed to A.
(b) If the vehicle has not run out of fuel, proceed to B.
B -- CHECK FOR INTERMITTENT PROBLEMS
A -- DTC IS CAUSED BY RUNNING OUT OF FUEL