2000 avalon heated oxygen sensor

[yamaha605]

Check engine light came on plugged my obd2 in and got p1135 and p1155. according to manual its bank one sensor one and bank 2 sensor 2 heater circuits. bank one sensor is reading right but i cant read back to ground on my plug that i plug the o2 sensor into where does the ground wire go to please help.

[Brian R.]

My information is that DTC P1155 relates to Bank 2 Sensor 1, not Bank 2 Sensor 2. Please double check your information.

Ground wire for Bank 1 Sensor 1 and Bank 2 Sensor 1 heater circuits go to connector E5 pins 3 and 4 on the ECM.

I don't believe you have a Bank 2 Sensor 2 in your vehicle. Both sensors you have to check are in front of the cat convertor. Your Sensor 1 sensors are both A/F ratio sensors. The sensor behind the cat convertor is Bank 1 Sensor 2 and is an HO2 sensor.

With ignition on, check voltage to ground of terminals HAFL and HAFR on ECM. (Top middle pair in second connector from left) Should be 9-14 V.

Check resistance of A/F sensor heater
(a) Disconnect the A/F sensor connector.
(b) Using an ohmmeter measure the resistance between terminals +B and HT (two connectors furthest from the two ridge side of the connector).
Resistance:
At 20°C (68°F) 0.8 - 1.4 ohms
At 800°C (1,472°F) 1.8 - 3.2 ohms

If the resistance is not as specified, replace the sensor.
Torque: 44 N·m (450 kgf·cm, 32 ft·lbf)
(c) Reconnect the A/F sensor connector.

Check A/F sensor heater relay (Marking: A/F HTR in relay box next to battery).
1. REMOVE RELAY BOX COVER

2. REMOVE A/F SENSOR HEATER RELAY

3. INSPECT A/F SENSOR HEATER RELAY CONTINUITY
(a) Using an ohmmeter, check that there is continuity between terminals 1 and 2 (Two terminals parallel to long side of relay). If there is no continuity, replace the relay.
(b) Check that there is no continuity between terminals 3 and 5 (Two terminals parallel to short side of relay) when no voltage is applied across 1 and 2. If there is continuity, replace the relay.

4. INSPECT A/F SENSOR HEATER RELAY OPERATION
(a) Apply battery voltage across terminals 1 and 2.
(b) Using an ohmmeter, check that there is continuity between terminals 3 and 5 at this time.
If there is no continuity, replace the relay.

I have a Toyota FSM if you need to download one.