Troubleshooting

DTC P0130 Oxygen Sensor Circuit (Bank 1 Sensor 1)

CIRCUIT DESCRIPTION

DTC Detecting Condition:

HINT: The ECM provides a pulse width modulated control circuit to adjust current through the heater. The A/F ratio sensor heater circuit uses a relay on the B+ side of the circuit.

To obtain a high purification rate for the CO, HC and NOx components of the exhaust gas, a three-way catalytic converter is used, but for the most efficient use of the three-way catalytic converter, the air-fuel ratio must be precisely controlled so that it is always close to the stoichiometric air-fuel ratio.

The oxygen sensor has the characteristic whereby its output voltage changes suddenly in the vicinity of the stoichiometric air-fuel ratio. This is used to detect the oxygen concentration in the exhaust gas and provide feedback to the computer for control of the air-fuel ratio.

When the air-fuel ratio becomes LEAN, the oxygen concentration in the exhaust increases and the oxygen sensor informs the ECM of the LEAN condition (small electromotive force: < 0.45 V).

When the air-fuel ratio is RICHER than the stoichiometric air-fuel ratio the oxygen concentration in the exhaust gas in reduced and the oxygen sensor informs the ECM of the RICH condition (large electromotive force: > 0.45 V).

The ECM judges by the electromotive force from the oxygen sensor whether the air-fuel ratio is RICH or LEAN and controls the injection time accordingly. However, if malfunction of the oxygen sensor causes output of abnormal electromotive force, the ECM is unable to perform accurate air-fuel ratio control. The oxygen sensors include a heater which heats the zirconia element. The heater is controlled by the ECM. When the intake air volume is low (the temp. of the exhaust gas is low) current flows to the heater to heat the sensor for accurate oxygen concentration detection.

HINT: Sensor 1 refers to the sensor closer to the engine body.
The oxygen sensor's output voltage and the short-term fuel trim value can be read using the OBD II scan tool or hand-held tester.

Wiring Diagram:

CONFIRMATION DRIVING PATTERN




1. Connect the hand-held tester to the DLC3.
2. Switch the hand-held tester from "normal mode" to "check mode".
3. Start the engine and let the engine idle for 100 sec. or more.
4. Drive the vehicle at 40 km/h (24 mph) or more for 20 sec. or more.
5. Let the engine idle for 20 sec. or more.
6. Let the engine idle for 30 sec.

HINT: If a malfunction exists, the MIL will light up during step (6).

NOTE:
If the conditions in this test are not strictly followed, detection of the malfunction will not be possible.
If you do not have a hand-held tester, turn the ignition switch OFF after performing steps (3) to (6), then perform steps (3) to (6) again.

Step 1 - 2:

Step 3 - 6:

Step 7 - 8:

INSPECTION PROCEDURE

HINT: Read freeze frame data using hand-held tester or OBD II scan tool. Because freeze frame records the engine conditions when the malfunction is detected, when troubleshooting it is useful for determining whether the vehicle was running or stopped, the engine warmed up or not, the air-fuel ratio lean or rich, etc. at the time of the malfunction.