Operation CHARM: Car repair manuals for everyone.

Heated Oxygen Sensor (HO2S) Heater

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. 15.7 Ohms

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).