Code 13, O2 Sensor CKT/Open CKT (VIN 5)

ECM supplies approximately .45 volt between ECM terminals D6 and D7. If voltage is measured with a 10-megohm DVOM, reading may be as low as .32 volt. The O2 sensor produces a varying voltage as engine reaches normal operating temperature. Voltage varies between .1-1.0 volt.

The O2 sensor will not produce voltage until sensor reaches 600°F (316°C). When sensor is less than this temperature, open loop condition exists.

1. Code 13 sets if the following conditions are present for 60 seconds:
   • Engine temperature is greater than 158°F (70°C).
   • Engine has been running for at least 120 seconds after start.
   • O2 signal voltage is steady between .347-.547 volt.
   • Throttle angle is greater than 5 percent.

   If condition for Code 13 exist, system will not go into closed Loop.

2. This test determines if O2 sensor, ECM and/or wiring is faulty.
3. Use only high-impedance DVOM when performing this test. This checks continuity of terminals D6 and D7. If D6 is open, ECM voltage on D7 will be greater than .6 volt (600 mV).