Heated Oxygen Sensor Heater Inspection
HEATED OXYGEN SENSOR (HO2S) HEATER INSPECTIONNOTE: Perform the following inspection only when directed.
Resistance Inspection
1. Disconnect the negative battery cable.
2. Disconnect the HO2S connector.
3. Measure the resistance between the HO2S terminals C and D using an ohmmeter.
- If the HO2S heater is okay, but the PID value is out of specification, perform the "Circuit Open/Short Inspection".
- If not as specified, replace the HO2S. (See EXHAUST SYSTEM REMOVAL/INSTALLATION.)
Specification
HO2S (RF, LF): 3.0 - 3.6 ohms
HO2S (RR, LR): 5.0 - 7.0 ohms
Circuit Open/Short Inspection
1. Disconnect the PCM connector.
2. Inspect the following harness for open or short circuit. (Continuity check)
Open circuit
- HO2S (RF) terminal C (harness-side) and ignition switch
- HO2S (RF) terminal D (harness-side) and PCM terminal 93 (harness-side)
- HO2S (LF) terminal C (harness-side) and ignition switch
- HO2S (LF) terminal D (harness-side) and PCM terminal 94 (harness-side)
- HO2S (RR) terminal C (harness-side) and ignition switch
- HO2S (RR) terminal D (harness-side) and PCM terminal 95 (harness-side)
- HO2S (LR) terminal C (harness-side) and ignition switch
- HO2S (LR) terminal D (harness-side) and PCM terminal 96 (harness-side)
Short circuit
- HO2S (RF) terminal C (harness-side) and body GND
- HO2S (RF) terminal D (harness-side) and power supply
- HO2S (RF) terminal D (harness-side) and body GND
- HO2S (LF) terminal C (harness-side) and body GND
- HO2S (LF) terminal D (harness-side) and power supply
- HO2S (LF) terminal D (harness-side) and body GND
- HO2S (RR) terminal C (harness-side) and body GND
- HO2S (RR) terminal D (harness-side) and power supply
- HO2S (RR) terminal D (harness-side) and body GND
- HO2S (LR) terminal C (harness-side) and body GND
- HO2S (LR) terminal D (harness-side) and power supply
- HO2S (LR) terminal D (harness-side) and body GND