Circuit Description

PCM supplies about 450 millivolts (mV) between HO2S high and low signal circuits. HO2S voltage ranges from about 1000 mV when exhaust is rich to about 10 mV when exhaust is lean. PCM monitors and stores sensor voltage information and evaluates voltage samples to determine amount of time sensor voltage is out of range. If PCM detects HO2S voltage is out bias range, DTC P0160 will set.

For duplication of DTC, ensure:

• DTCs P0101, P0102, P0103, P0112, P0113, P0117, P0118, P0121, P0122, P0123, P0125, P0200, P0335, P0336, P0351-P0358, P1120, P1220, P1221 or P1258 are not set.
• Engine has been running for more than 70 seconds.
• Fuel system is operating in closed-loop.
• System voltage is greater than 9 volts.
• AIR, EGR and catalyst diagnostics are not active.