HEATED OXYGEN SENSOR (HO2S) INSPECTION [AJ] (VIN: JM0 LW10J300 301406-, JMZ LW69J7*# 307683-, JM8 LW28J**# 301514-, JM8 LW28A**# 301514- (Assumed))

Note

• Perform the following test only when directed.

HO2S Voltage Inspection

1. Turn the ignition switch to LOCK.

2. Connect the WDS or equivalent to the DLC-2.

3. Warm up the engine to normal operating temperature.

4. Using the WDS or equivalent, monitor the following:

- Vehicle speed (PID: VSS)

- Engine speed (PID: RPM)

- HO2S voltage (PID: O2S11)

5. Drive the vehicle and decelerate the engine speed by releasing the accelerator pedal fully when the engine speed is 3,000 rpm or more.

6. Verify that the HO2S outputs a voltage of 0.6 V or more, one time or more, then verify that the HO2S voltage (PID: O2S11) is 0.3 V or less while decelerating as shown in the figure.

• If not within the specification, inspect the HO2S for an open or short circuit. (See HO2S Circuit Open/Short Inspection.) Then if there is no malfunction in the wiring harness, replace the HO2S.

HO2S Circuit Open/Short Inspection

1. Disconnect the PCM connector. (SeePCM REMOVAL/INSTALLATION [AJ] .)

2. Inspect the following wiring harness for open or short circuit (Continuity check).

Open circuit

• If there is no continuity, the circuit is open. Repair or replace the harness.

- HO2S (Front, RH) terminal A and 104 pin PCM terminal 18

- HO2S (Front, RH) terminal B and 104 pin PCM terminal 20

- HO2S (Rear, RH) terminal A and 104 pin PCM terminal 44

- HO2S (Rear, RH) terminal B and 104 pin PCM terminal 20

- HO2S (Front, LH) terminal A and 104 pin PCM terminal 19

- HO2S (Front, LH) terminal B and 104 pin PCM terminal 20

- HO2S (Rear, LH) terminal A and 104 pin PCM terminal 45

- HO2S (Rear, LH) terminal B and 104 pin PCM terminal 20

Short circuit

• If there is continuity, the circuit is shorted. Repair or replace the harness.

- HO2S (Front, RH) terminal A and body ground

- HO2S (Front, RH) terminal A and power supply

- HO2S (Front, RH) terminal B and power supply

- HO2S (Rear, RH) terminal A and body ground

- HO2S (Rear, RH) terminal A and power supply

- HO2S (Rear, RH) terminal B and power supply

- HO2S (Front, LH) terminal A and body ground

- HO2S (Front, LH) terminal A and power supply

- HO2S (Front, LH) terminal B and power supply

- HO2S (Rear, LH) terminal A and body ground

- HO2S (Rear, LH) terminal A and power supply

- HO2S (Rear, LH) terminal B and power supply

HO2S Heater Resistance Inspection

1. Disconnect the HO2S (front or rear) connector.

2. Measure the resistance between the following HO2S terminals.

• HO2S (Front, RH) and HO2S (Rear, RH)

- Terminal C and D

• HO2S (Front, LH) and HO2S (Rear, LH)

- Terminal C and D

• If not as specified, replace the HO2S.

• If the HO2S heater is okay, but PID value is out of specification, perform the "Circuit Open/Short Inspection".

Front (RH, LH): 2-20 ohms

Rear (RH, LH): 2-50 ohms

HO2S heater Circuit Open/Short Inspection

1. Disconnect the PCM connector. (See PCM REMOVAL/INSTALLATION [AJ].)

2. Inspect the following wiring harness for open or short circuit (Continuity check).

Open circuit

• If there is no continuity, the circuit is open. Repair or replace the harness.

- HO2S (Front, RH) terminal C and power supply

- HO2S (Front, RH) terminal D and 104 pin PCM terminal 83

- HO2S (Rear, RH) terminal C and power supply

- HO2S (Rear, RH) terminal D and 104 pin PCM terminal 57

- HO2S (Front, LH) terminal C and power supply

- HO2S (Front, LH) terminal D and 104 pin PCM terminal 84

- HO2S (Rear, LH) terminal C and power supply

- HO2S (Rear, LH) terminal D and 104 pin PCM terminal 58

Short circuit

• If there is continuity, the circuit is shorted. Repair or replace the harness.

- HO2S (Front, RH) terminal C and body ground

- HO2S (Front, RH) terminal D and body ground

- HO2S (Front, RH) terminal D and power supply

- HO2S (Rear, RH) terminal C and body ground

- HO2S (Rear, RH) terminal D and body ground

- HO2S (Rear, RH) terminal D and power supply

- HO2S (Front, LH) terminal C and body ground

- HO2S (Front, LH) terminal D and body ground

- HO2S (Front, LH) terminal D and power supply

- HO2S (Rear, LH) terminal C and body ground

- HO2S (Rear, LH) terminal D and body ground

- HO2S (Rear, LH) terminal D and power supply