Code 13, Open Oxygen Sensor Circuit: Notes
WARNING: This page is about a different car, the 1990 Chevrolet Corvette. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
Test numbers refer to test numbers on diagnostic chart.
Test Number 1) This tests if problem still exists. Vehicle cannot enter closed loop mode if oxygen sensor circuit is open. Code 13 indicates an open in the O2 sensor circuit. Code will set if:
- Engine is at normal operating temperature.
- Neither Code 21 nor Code 22 are stored.
- O2 sensor voltage is constant within a specified range (.34-.55 volt).
- Throttle angle is greater than idle.
- A precalibrated amount of time has elapsed since start-up.
- All conditions have existed for a precalibrated amount of time.
Test Number 2) Determines if O2 sensor, wiring or control module is at fault. If wiring is good, grounding oxygen sensor wire will cause .45 volt reference supplied by the control module to pull low.
Test Number 3) This tests O2 sensor circuit wiring. Use only a high impedance (10-megohm minimum) digital voltmeter.