Code 13 (MFI CALIF. & New YORK) -: Notes

Heated Oxygen (O2) sensor produces a voltage that varies within a range of about 0.1 volt (lean exhaust) to 1.0 volt (rich exhaust). ECM monitors voltage and determines if exhaust is lean or rich. O2 sensor has a built-in heater that keeps O2 sensor at operating temperature while engine is running. Code 13 will set if the following conditions are met for at least 30 seconds and the A/D conversion value of heated O2 output voltage does not exceed .45 volt.

• Engine operating temperature is greater than 158°F (70°C).
• Engine speed is greater than 2100 RPM.
• Has not achieved fuel cut mode.
  NOTE: Test numbers refer to test numbers on diagnostic chart.

1. Checks for heated O2 voltage activity.
2. Checks for open in Gray/Yellow wire between ECM and heated O2 sensor, or a faulty ECM.
3. Checks for short to voltage in Yellow/Blue wire between ECM and heated O2 sensor, or a faulty ECM or heated O2 sensor.
4. Checks for open or short to ground in Yellow/Blue wire between ECM and heated O2 sensor, a faulty ECM or heated O2 sensor.