For California
DTC P0131 A/F SENSOR 1
Component Description
The air fuel ratio (A/F) sensor 1 is a planar one-cell limit current sensor. The sensor element of the A/F sensor 1 is composed an electrode layer, which transports ions. It has a heater in the element.
The sensor is capable of precise measurement lambda = 1, but also in the lean and rich range. Together with its control electronics, the sensor outputs a clear, continuous signal throughout a wide lambda range.
The exhaust gas components diffuse through the diffusion layer at the sensor cell. An electrode layer is applied voltage, and this current relative oxygen density in lean. Also this current relative hydrocarbon density in rich.
Therefore, the A/F sensor 1 is able to indicate air fuel ratio by this electrode layer of current. In addition, a heater is integrated in the sensor to ensure the required operating temperature of about 800�C (1,472�F).
CONSULT-III Reference Value in Data Monitor Mode
Specification data are reference values.
On Board Diagnosis Logic
To judge the malfunction, the diagnosis checks that the A/F signal computed by ECM from the air fuel ratio (A/F) sensor 1 signal is not inordinately low.
DTC Confirmation Procedure
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at least 10 seconds before conducting the next test.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 10.5 V at idle.
WITH CONSULT-III
1. Start engine and warm it up to normal operating temperature.
2. Select "A/F SEN1 (B1)" in "DATA MONITOR" mode with CONSULT-III.
3. Check "A/F SEN1 (B1)" indication.
If the indication is constantly approx. 0 V, go to For California.
If the indication is not constantly approx. 0 V, go to next step.
4. Turn ignition switch OFF, wait at least 10 seconds and then restart engine.
5. Drive and accelerate vehicle to more than 40 km/h (25 MPH) within 20 seconds after restarting engine.
6. Maintain the following conditions for about 20 consecutive seconds.
NOTE:
- Keep the accelerator pedal as steady as possible during the cruising.
- If this procedure is not completed within 1 minute after restarting engine at step 4, return to step 4.
7. Check 1st trip DTC.
8. If 1st trip DTC is displayed, go to For California.
WITH GST
Follow the procedure "WITH CONSULT-III" above.
Wiring Diagram
EC-A/F-01:
Specification data are reference values and are measured between each terminal and ground.
Pulse signal is measured by CONSULT-III.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in damage to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
Diagnosis Procedure
1.CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten ground screws on the body. For California.
Arrow Indicates Vehicle front
- Body ground (1)
OK or NG
OK - GO TO 2.
NG - Repair or replace ground connections.
2.CHECK AIR FUEL RATIO (A/F) SENSOR 1 POWER SUPPLY CIRCUIT
1. Disconnect A/F sensor 1 harness connector (1).
2. Turn ignition switch ON.
3. Check voltage between A/F sensor 1 terminal 4 and ground with
CONSULT-III or tester.
Voltage: Battery voltage
OK or NG
OK - GO TO 4.
NG - GO TO 3.
3.DETECT MALFUNCTIONING PART
Check the following.
- Harness connectors E3, F2
- 10 A fuse
- Harness for open or short between A/F sensor 1 and fuse
- Repair or replace harness or connectors.
4.CHECK A/F SENSOR 1 INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between the following terminals. Refer to Wiring Diagram.
Continuity should exist.
4. Check harness continuity between ECM terminals 49, 53 or A/F sensor 1 terminals 1, 2 and ground. Refer to Wiring Diagram.
Continuity should not exist.
5. Also check harness for short to power.
OK or NG
OK - GO TO 5.
NG - Repair open circuit or short to ground or short to power in harness or connectors.
5.CHECK INTERMITTENT INCIDENT
Perform For California For California.
OK or NG
OK - GO TO 6.
NG - Repair or replace.
6.REPLACE AIR FUEL RATIO (A/F) SENSOR 1
Replace air fuel ratio (A/F) sensor 1.
CAUTION:
- Discard any A/F sensor which has been dropped from a height of more than 0.5 m (19.7 in) onto a hard surface such as a concrete floor; use a new one.
- Before installing new A/F sensor, clean exhaust system threads using Oxygen Sensor Thread Cleaner tool J-43897-18 or J-43897-12 and approved anti-seize lubricant.
- INSPECTION END
Removal and Installation
AIR FUEL RATIO SENSOR
Component.