Code 13, Left Heated Oxygen Sensor Circuit Open: Notes

NOTE: The 5.7L (VIN P) engine is equipped with 2 oxygen sensors. On this model, code will set if the left sensor circuit is open. Code 63 will set if the right sensor circuit is open. Oxygen sensors use a heating element. Heating element is not controlled by PCM.

Code will set if Codes 21 and 22 are not set, engine is at normal operating temperature, oxygen sensor voltage is constant within a specified range (.35-.55 volt), throttle angle is greater than idle, a precalibrated amount of time has elapsed since start-up and all conditions have existed for a precalibrated amount of time. Most likely causes of code are: open sensor signal (high) circuit, faulty PCM connection, faulty PCM, faulty oxygen sensor connection or faulty oxygen sensor.

NOTE: Test numbers refer to numbers on diagnostic chart.

This tests if problem still exists. Vehicle cannot enter "closed loop" mode if oxygen sensor circuit is open. Code indicates an open in O2 sensor circuit (steady .35-.55 volt).
Determines if oxygen sensor, wiring or control module is at fault. If wiring is good, grounding oxygen sensor wire will cause .45 volt reference supplied by control module to pull low.
This tests oxygen sensor circuit wiring. Use only a high impedance (10-megohm minimum) digital voltmeter.