Resistance Inspection
HO2S Heater Resistance Inspection1. Disconnect the HO2S (front, middle, or rear) connector.
2. Measure the resistance between the following HO2S terminals.
- HO2S (Front, RH) and HO2S (Rear, RH)
- Terminal C and D
- HO2S (Front, LH), HO2S (Rear, LH), HO2S (Middle) and HO2S (Rear)
- Terminal A and B
- If not as specified, replace the HO2S
- If the HO2S heater is okay, 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
Middle: Approx. 15.7 Ohms (Federal emission regulation applicable models)
Rear (RH, LH): 14.2 - 18.8 Ohms (California emission regulation applicable models), Approx. 15.7 Ohms (Federal emission regulation applicable models)
Circuit Open/Short Inspection
1. Disconnect the PCM connector.
2. Connect the SST (104 Pin Breakout Box) with the PCM disconnected.
3. Tighten the connector attaching bolt.
Tightening torque
7.9 - 10.7 N.m {80 - 110 kgf.cm, 69.5 - 95.4 in.lbf}
4. 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.
- Front HO2S (RH) terminal C (harness-side) and power supply
- Front HO2S (RH) terminal D (harness-side) and 104 pin breakout box terminal 93
- Rear HO2S (RH) terminal C (harness-side) and power supply
- Rear HO2S (RH) terminal D (harness-side) and 104 pin breakout box terminal 95
- Front HO2S (RH) terminal A (harness-side) and power supply
- Front HO2S (RH) terminal B (harness-side) and 104 pin breakout box terminal 94
- Rear HO2S (LH) terminal A (harness-side) and power supply
- Rear HO2S (LH) terminal B (harness-side) and 104 pin breakout box terminal 96
- Middle HO2S terminal A (harness-side) and power supply
- Middle HO2S terminal B (harness-side) and 104 pin breakout box terminal 95
- Rear HO2S terminal A (harness-side) and power supply
- Rear HO2S terminal B (harness-side) and 104 pin breakout box terminal 96
Short circuit
- If there is continuity, the circuit is shorted. Repair or replace the harness.
- Front HO2S (RH) terminal C (harness-side) and body ground
- Front HO2S (RH) terminal D (harness-side) and body ground
- Front HO2S (RH) terminal D (harness-side) and power supply
- Rear HO2S (RH) terminal C (harness-side) and body ground
- Rear HO2S (RH) terminal D (harness-side) and body ground
- Rear HO2S (RH) terminal D (harness-side) and power supply
- Front HO2S (LH) terminal C (harness-side) and body ground
- Front HO2S (LH) terminal A (harness-side) and body ground
- Front HO2S (LH) terminal A (harness-side) and power supply
- Rear HO2S (LH) terminal A (harness-side) and body ground
- Rear HO2S (LH) terminal B (harness-side) and body ground
- Rear HO2S (LH) terminal B (harness-side) and power supply
- Middle HO2S terminal A (harness-side) and body ground
- Middle HO2S terminal B (harness-side) and body ground
- Middle HO2S terminal B (harness-side) and power supply
- Rear HO2S terminal A (harness-side) and body ground
- Rear HO2S terminal B (harness-side) and body ground
- Rear HO2S terminal B (harness-side) and power supply