Protege DX L4-1.6L DOHC (2000)
Oxygen Sensor: Testing and Inspection
Resistance Inspection
HO2S Heater (Front and Rear) Resistance inspection
1. Disconnect the HO2S (Front or Rear) connector.
2. Measure the resistance between HO2S terminals C and D using an ohmmeter.
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If not as specified, replace the HO2S.
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If the HO2S heater is okay, but PID value or PCM terminal 94 (Front), 93 (Rear) voltage are out of specification, carry out the "Circuit
Open/Short Inspection".
Specification
Front: Approx. 5.6 Ohms (California)
Approx. 15.7 Ohms (Except California)
Rear: Approx. 15.7 Ohms
Circuit Open/Short Inspection
1. Remove the PCM.
2. Connect the SST (104 Pin Breakout Box) to the PCM as shown.
3. Tighten the connector attaching screw.
Tightening torque
7.9 - 10.7 N.m {80 - 110 kgf.cm, 69.5 - 95.4 in.lbf}
4. Inspect for an open or short circuit in the following wiring harnesses by probing the applicable sensor and SST (104 Pin Breakout Box) terminals
with ohmmeter leads.
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If there is an open or short circuit, repair or replace wiring harnesses.
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If there is no open or short circuit, replace the HO2S.
Open circuit
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Power circuit (HO2S connector terminal C and ignition switch (IG1) circuit through common connector)
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GND circuit (HO2S connector terminal D and PCM connector terminal 94 (Front), 93 (Rear))
Short circuit
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Power circuit (HO2S connector terminal C and ignition switch (IG1) circuit through common connector to GND)
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GND circuit (HO2S connector terminal D and PCM connector terminal 94 (Front), 93 (Rear) to GND)
5. Reconnect the HO2S connector.