Code 45 (DOHC) - O2 Sensor Rich Fuel Mixture (Heated Sensor): Notes

The ECM supplies a voltage of approximately .45 volt between ECM terminals D6 and D7 (if measurement is taken with a 10-megohm DVOM, reading may be as low as .32 volt). The O2 sensor varies voltage from approximately .1 volt (lean exhaust) to 1.0 volt (rich exhaust). When sensor temperature is less than 600°F (316°C), the sensor acts like an open circuit and will not produce voltage. An open sensor circuit or cold sensor will cause an open loop condition.

1. Code 45 will set when sensor voltage signal is greater than .75 volt under following conditions:
   • Coolant temperature is greater than 157°F (69.5°C).
   • Integrator count is not at 128.
   • No Code 21A, 21B, 33A or 33B is set.
   • TPS is greater than 10 percent (A/T) or 8 percent (M/T).
   • System is in closed loop.