P0133
3UZ-FE ENGINE CONTROL SYSTEM: SFI SYSTEM: P0133: Oxygen Sensor Circuit Slow Response (Bank 1 Sensor 1)
DTC P0133 - Oxygen Sensor Circuit Slow Response (Bank 1 Sensor 1)
DTC P0153 - Oxygen Sensor Circuit Slow Response (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 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.
MONITOR DESCRIPTION
The ECM uses the heated oxygen sensor information to regulate the air-fuel ratio close to the stoichiometric air-fuel ratio. This maximizes the catalytic converter's ability to purify the exhaust gases. The sensor detects oxygen levels in the exhaust gas and sends a signal to the ECM.
The inner surface of the sensor element is exposed to outside air. The outer surface of the sensor element is exposed to the exhaust gases. The sensor element is made of platinum coated zirconia and includes an integrated heating element. The heated oxygen sensor's output voltage changes suddenly in the vicinity of the stoichiometric air-fuel ratio. The heated oxygen sensor generates waveforms of a voltage between 0.1 V and 0.9 V in response to the oxygen concentration in the exhaust gas. When the heated oxygen sensor voltage is 0.45 V or more, the ECM judges that the air-fuel ratio is rich. When it is 0.45 V or less, the ECM judges that the air-fuel ratio is lean. The ECM monitors the response feature of the heated oxygen sensor. If the response time of the heated oxygen sensor status change from rich to lean (or vice versa) becomes longer, the ECM interprets this as a malfunction in the heated oxygen sensor and sets a DTC.
MONITOR STRATEGY
TYPICAL ENABLING CONDITIONS
All:
Heated oxygen sensor (sensor 1) response:
Heated oxygen sensor (sensor 1) frequency:
TYPICAL MALFUNCTION THRESHOLDS
Heated oxygen sensor (sensor 1) response:
Heated oxygen sensor (sensor 1) frequency:
MONITOR RESULT
Refer to CHECKING MONITOR STATUS Mode 6 Data.
WIRING DIAGRAM
CONFIRMATION DRIVING PATTERN
- (a) Connect the Techstream to the DLC3.
- (b) Switch the tester from normal mode to check mode Check Mode Procedure.
- (c) Allow the engine to idle until the ECT reaches 75°C (167°F).
- (d) Allow the vehicle to run at 40 km/h (25 mph) or more for 25 seconds or more.
- (e) Allow the engine to idle for 30 seconds or more.
- (f) Perform steps (d) and (e) at least 3 times.
HINT: If a malfunction exists, the MIL will be illuminated.
- (g) Allow the engine to idle for 30 seconds.
NOTE:
If the conditions in this test are not strictly followed, you should perform steps (d) and (e).
If you do not have the Techstream, turn the ignition switch OFF after performing steps (c) and (f), and then perform steps (c) and (f) again.
INSPECTION PROCEDURE
HINT: It is possible that the malfunctioning area can be found using the Active Test Control the Injection Volume to 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 voltages of the heated oxygen sensors.
- Procedure:
1 Connect the Techstream to the DLC3.
2 Turn the ignition switch ON.
3 Warm up the engine by running the engine at 2,500 rpm for approximately 90 seconds.
4 Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the Injection Volume for A/F Sensor.
5 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
NOTE:
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.
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) Enter the following menus: Powertrain / Engine and ECT / Trouble Codes
(c) Read the DTCs.
Result:
B -- GO TO RELEVANT DTC CHART
A -- Continue to next step.
2. READ VALUE USING TECHSTREAM (HEATED OXYGEN SENSOR (SENSOR 1) VOLTAGE)
(a) Connect the Techstream to the DLC3.
(b) Enter the following menus: Powertrain / Engine and ECT / Data List / O2S B1 S1 or O2S B2 S1.
(c) Allow the engine to run for 90 seconds at 2,500 rpm.
(d) Read the heated oxygen sensor voltage while the engine is idling.
OK:
The heated oxygen sensor voltage alternates between less than 0.4 V and more than 0.55 V, and the period "t" must be less than 0.9 seconds (see the following table).
OK -- PERFORM CONFIRMATION DRIVING PATTERN
NG -- Continue to next step.
3. 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.
4. INSPECT EFI RELAY (Marking: EFI)
(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.
5. CHECK WIRE HARNESS (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 AND CONNECTOR
OK -- Continue to next step.
6. 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.
7. CHECK FUEL PRESSURE
(a) Check the fuel pressure Testing and Inspection.
NG -- REPAIR OR REPLACE FUEL SYSTEM
OK -- Continue to next step.
8. 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
OK -- REPLACE HEATED OXYGEN SENSOR
9. PERFORM CONFIRMATION DRIVING PATTERN
HINT: Clear all DTCs before performing the confirmation driving pattern.
NEXT -- Continue to next step.
10. READ OUTPUT DTC (DTC P0133 OR P0153 IS OUTPUT AGAIN)
(a) Clear the DTC DTC Check / Clear.
(b) Start the engine and allow the engine to idle for 15 seconds or more.
(c) Read the DTC.
Result:
B -- CHECK FOR INTERMITTENT PROBLEMS
A -- REPLACE HEATED OXYGEN SENSOR