P0133
DTC P0133 Oxygen Sensor Circuit Slow Response (Bank 1 Sensor 1)DTC P0153 Oxygen Sensor Circuit Slow Response (Bank 2 Sensor 1)
DESCRIPTION
DTC Detection Condition:
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
Monitor Strategy (Part 1):
Monitor Strategy (Part 2):
Typical Enabling Conditions:
Typical Malfunctions Thresholds:
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 RESULT
Refer to CHECKING MONITOR STATUS. Mode 6 Data
CONFIRMATION DRIVING PATTERN
a. Connect the intelligent tester to the CAN VIM. Then connect the CAN VIM to the DLC3.
b. Switch the intelligent tester from normal mode to check mode.
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.
f. Perform steps (d) and (e) at least 3 times.
HINT: If a malfunction exists, the MIL will be illuminated on the multi-information display.
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 intelligent tester, turn the ignition switch OFF after performing steps (c) to (f), then perform steps (c) to (f) again.
Wiring Diagram:
Step 1:
Step 1(Continued)-3:
Step 4-6:
Step 6(Continued)-10:
INSPECTION PROCEDURE
HINT: It is possible that the malfunctioning area can be found using the ACTIVE TEST A/F CONTROL 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:
a. Connect the intelligent tester to the CAN VIM. Then connect the CAN VIM to the DLC3.
b. Turn the ignition switch ON.
c. Warm up the engine by running the engine at 2,500 rpm for approximately 90 seconds.
d. Enter the following menus: DIAGNOSIS / ENHANCED OBD II / ACTIVE TEST / A/F CONTROL.
e. 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 intelligent tester. 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.