HEATED OXYGEN SENSOR (HO2S) INSPECTION [AJ]

BME014018860202

HO2S Voltage Inspection

Note
• Perform the following test only when directed.

1. Warm up the engine and run it at idle.

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

3. Connect the voltmeter test leads to the following HO2S terminals:

European (L.H.D.) specs.
• HO2S (Front, RH) and HO2S (Rear, RH)
- (+) lead-terminal A
- (-) lead-terminal B
• HO2S (Front, LH) and HO2S (Rear, LH)
- (+) lead-terminal A
- (-) lead-terminal B
Australian, General (L.H.D. R.H.D.) specs.
• HO2S (Front, RH)
- (+) lead-terminal A
- (-) lead-terminal B
• HO2S (Front, LH)
- (+) lead-terminal A
- (-) lead-terminal B

4. Run the engine at 3,000 rpm until the voltmeter moves between approx. 0 and 1.0 V.

5. Verify that the measurement voltage changes when the engine speed increases and decreases suddenly several times.

• If not as specified, replace the HO2S.
• If the HO2S is normal, but PID value or PCM terminal voltages are out of specification, perform the "Circuit Open/Short Inspection".

Specification

Engine speed

Voltage (V)

Increase
0.5-1.0
Decrease
0-0.5

HO2S Circuit Open/Short Inspection

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

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

Open circuit

• If there is no continuity, the circuit is open. Repair or replace the harness.
European (L.H.D.) specs.
- HO2S (Front, RH) terminal A (harness-side) and PCM terminal 60
- HO2S (Front, RH) terminal B (harness-side) and PCM terminal 91
- HO2S (Rear, RH) terminal A (harness-side) and PCM terminal 35
- HO2S (Rear, RH) terminal B (harness-side) and PCM terminal 91
- HO2S (Front, LH) terminal A (harness-side) and PCM terminal 87
- HO2S (Front, LH) terminal B (harness-side) and PCM terminal 91
- HO2S (Rear, LH) terminal A (harness-side) and PCM terminal 61
- HO2S (Rear, LH) terminal B (harness-side) and PCM terminal 91
Australian, General (L.H.D. R.H.D.) specs.
- HO2S (Front, RH) terminal A (harness-side) and PCM terminal 60
- HO2S (Front, RH) terminal B (harness-side) and PCM terminal 91
- HO2S (Front, LH) terminal A (harness-side) and PCM terminal 87
- HO2S (Front, LH) terminal B (harness-side) and PCM terminal 91

Short circuit

• If there is continuity, the circuit is shorted. Repair or replace the harness.
European (L.H.D.) specs.
- HO2S (Front, RH) terminal A (harness-side) and body ground
- HO2S (Front, RH) terminal A (harness-side) and power supply
- HO2S (Front, RH) terminal B (harness-side) and power supply
- HO2S (Rear, RH) terminal A (harness-side) and body ground
- HO2S (Rear, RH) terminal A (harness-side) and power supply
- HO2S (Rear, RH) terminal B (harness-side) and power supply
- HO2S (Front, LH) terminal A (harness-side) and body ground
- HO2S (Front, LH) terminal A (harness-side) and power supply
- HO2S (Front, LH) terminal B (harness-side) and power supply
- HO2S (Rear, LH) terminal A (harness-side) and body ground
- HO2S (Rear, LH) terminal A (harness-side) and power supply
- HO2S (Rear, LH) terminal B (harness-side) and power supply
Australian, General (L.H.D. R.H.D.) specs.
- HO2S (Front, RH) terminal A (harness-side) and body ground
- HO2S (Front, RH) terminal A (harness-side) and power supply
- HO2S (Front, RH) terminal B (harness-side) and power supply
- HO2S (Front, LH) terminal A (harness-side) and body ground
- HO2S (Front, LH) terminal A (harness-side) and power supply
- HO2S (Front, LH) terminal B (harness-side) and power supply

HO2S Heater Resistance Inspection

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

2. Measure the resistance between the following HO2S terminals.

European (L.H.D.) specs.
• HO2S (Front, RH) and HO2S (Rear, RH)
- Terminal C and D
• HO2S (Front, LH) and HO2S (Rear, LH)
- Terminal C and D
Australian, General (L.H.D. R.H.D.) specs.
• HO2S (Front, RH)
- Terminal C and D
• HO2S (Front, LH)
- Terminal C and D
• If not as specified, replace the HO2S.
• If the HO2S heater is normal, but PID value or any of PCM terminal 94, 93, 95, 96 voltage are out of specification, perform the "Circuit Open/Short Inspection".
Specification
Front (RH, LH): 5.0-6.8 ohms
Rear (RH, LH): 14.1-18.9 ohms

Circuit Open/Short Inspection

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

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

Open circuit

• If there is no continuity, the circuit is open. Repair or replace the harness.
European (L.H.D.) specs.
- HO2S (Front, RH) terminal C (harness-side) and power supply
- HO2S (Front, RH) terminal D (harness-side) and PCM terminal 93
- HO2S (Rear, RH) terminal C (harness-side) and power supply
- HO2S (Rear, RH) terminal D (harness-side) and PCM terminal 95
- HO2S (Front, LH) terminal C (harness-side) and power supply
- HO2S (Front, LH) terminal D (harness-side) and PCM terminal 94
- HO2S (Rear, LH) terminal C (harness-side) and power supply
- HO2S (Rear, LH) terminal D (harness-side) and PCM terminal 96
Australian, General (L.H.D. R.H.D.) specs.
- HO2S (Front, RH) terminal C (harness-side) and power supply
- HO2S (Front, RH) terminal D (harness-side) and PCM terminal 93
- HO2S (Front, LH) terminal C (harness-side) and power supply
- HO2S (Front, LH) terminal D (harness-side) and PCM terminal 94

Short circuit

• If there is continuity, the circuit is shorted. Repair or replace the harness.
- HO2S (Front, RH) terminal C (harness-side) and body ground
- HO2S (Front, RH) terminal D (harness-side) and body ground
- HO2S (Front, RH) terminal D (harness-side) and power supply
- HO2S (Rear, RH) terminal C (harness-side) and body ground
- HO2S (Rear, RH) terminal D (harness-side) and body ground
- HO2S (Rear, RH) terminal D (harness-side) and power supply
- HO2S (Front, LH) terminal C (harness-side) and body ground
- HO2S (Front, LH) terminal D (harness-side) and body ground
- HO2S (Front, LH) terminal D (harness-side) and power supply
- HO2S (Rear, LH) terminal C (harness-side) and body ground
- HO2S (Rear, LH) terminal D (harness-side) and body ground
- HO2S (Rear, LH) terminal D (harness-side) and power supply
Australian, General (L.H.D. R.H.D.) specs.
- HO2S (Front, RH) terminal C (harness-side) and body ground
- HO2S (Front, RH) terminal D (harness-side) and body ground
- HO2S (Front, RH) terminal D (harness-side) and power supply
- HO2S (Front, LH) terminal C (harness-side) and body ground
- HO2S (Front, LH) terminal D (harness-side) and body ground
- HO2S (Front, LH) terminal D (harness-side) and power supply