Montero V6-3.8L SOHC (2005)
Oxygen Sensor: Testing and Inspection
HEATED OXYGEN SENSOR CHECK
Required Special Tools:
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MB991316: Test Harness Set
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MD998464: Test Harness
<Left bank heated oxygen sensor (front)>
1. Using scan tool MB991958, observe HO2S reading. If values are unsatisfactory, or if a scan tool is not available, use the following procedure:
1. Disconnect the heated oxygen sensor connector and connect special tool MB991316 to the connector on the heated oxygen sensor side.
2. Make sure that there is continuity [4.5 - 8.0 ohms at 20°C (68°F)] between terminal No.1 (red clip of special tool) and terminal No.3 (blue
clip of special tool) on the heated oxygen sensor connector
3. If there is no continuity, replace the heated oxygen sensor.
4. Warm up the engine until engine coolant is 80°C (176°F) or higher.
5. Perform a racing for 5 minutes or more with the engine speed of 4,500 r/min.
6. Connect a digital voltage meter between terminal No.2 (black clip) and terminal No.4 (white clip).
2. While repeatedly revving the engine, measure the heated oxygen sensor output voltage.
CAUTION:
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Be very careful when connecting the jumper wire; incorrect connection can damage the heated oxygen sensor.
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Be careful the heater is broken when voltage of beyond 8 volts is applied to the heated oxygen sensor heater.
NOTE: If the sufficiently high temperature [of approximate 400°C (752°F) or more] is not reached although the heated oxygen sensor is normal,
