LEMON Manuals: Even more car manuals for everyone
Home >> Buick >> 1987 >> Skyhawk Sport, 2.0 1, Standard >> Repair and Diagnosis >> Engine Performance >> System >> 2.0L PFI Tests >> Diagnostic Code Flow Charts >> Code 13, Open Oxygen Sensor Circuit >> Notes

Code 13, Open Oxygen Sensor Circuit: Notes

Code 13 will set 2 minutes after engine start if the ECM receives a steady O2 signal voltage between .35-.55 volts for more than one minute with TPS signal at more than 6.5 percent. Engine must also be at normal operating temperature.

Possible causes of a Code 13 are a faulty O2 sensor, faulty wiring or terminals, or a faulty ECM.

NOTE: Test numbers refer to test numbers on diagnostic chart.
  1. This test allows the ECM to confirm either open or closed loop operation. If the condition for Code 13 exists, the system will not go into closed loop.
  2. This test will determine if the sensor is at fault or the wiring to the ECM is the cause of Code 13.
  3. Use only a high impedance digital volt ohm meter when doing this test. This test checks the continuity of circuits No. 412 and 413. If circuit No. 413 is open the ECM voltage on circuit No. 412 will be over .6 volts (600 mv).
scientia non olet · About LEMON Manuals