Heated Oxygen Sensor (HO2S) Heater

HEATED OXYGEN SENSOR (HO2S) HEATER INSPECTION

Inspection of Resistance

NOTE: Perform the following test only when directed.

1. Disconnect the HO2S connector.




2. Measure the resistance between HO2S terminals C and D using an ohmmeter.
- If not as specified, replace the HO2S.
- If HO2S heater is okay, but PID value is out of specification, perform the "Circuit Open/Short Inspection".

Specification
Approx. 5.6 Ohms (Front)
Approx. 15.7 Ohms (Rear)

3. Reconnect the HO2S connector.

Circuit Open/Short Inspection




Open circuit
- If there is no continuity, the circuit is open. Repair or replace the harness.
- GND circuit (HO2S connector D and PCM connector terminal 3J through common connector (Front).)
- Power circuit (HO2S connector terminal C and ignition switch (IG1) circuit through common connector (Front).)
- GND circuit (HO2S connector terminal D and PCM connector terminal 3P (Rear).)
- Power circuit (HO2S connector terminal C and ignition switch (IG1) circuit through common connector (Rear).)

Short circuit
- If there is continuity, the circuit is shorted. Repair or replace the harness.
- HO2S connector terminal C and ignition switch (IG1) through common connector to GND (Front).
- HO2S connector terminal D and PCM connector terminal 3J through common connector to GND (Front).
- HO2S connector terminal D and PCM connector terminal 3P to GND (Rear).