Code 13
Code 13 is a diagnostic trouble code related to the oxygen sensor circuit on the Pontiac Fiero.
Code 13 indicates that the ECM has detected a problem with the oxygen sensor signal or circuit.
Overview
The oxygen sensor sends a changing voltage signal to the ECM during normal operation. The ECM uses this signal to monitor exhaust oxygen content and adjust fuel mixture during closed-loop operation.
Code 13 is set when the ECM detects no normal variation in the oxygen sensor voltage signal during normal operation.
This usually means the oxygen sensor is disconnected, the sensor circuit has a wiring or connector problem, or the oxygen sensor needs to be replaced. A sticking or misadjusted Throttle position sensor may also contribute to this condition.
Flash pattern
Code 13 is displayed as:
- One flash
- Pause
- Three flashes
This represents code 13.
Animated flash pattern:
Meaning
Code 13 usually indicates an oxygen sensor circuit problem.
Possible causes include:
- Faulty oxygen sensor
- Oxygen sensor wiring problem
- Poor connector contact
- Exhaust leak near the sensor
- Sensor not reaching operating temperature
- ECM input problem
- Poor ground or related electrical fault
Symptoms
Possible symptoms may include:
- Check engine light
- Poor fuel economy
- Rich or lean running
- Rough idle
- Hesitation
- Failed emissions test
- Little or no obvious drivability problem
Diagnosis
Basic diagnostic checks include:
- Confirm that Code 13 is present.
- Inspect the oxygen sensor wiring and connector.
- Check for exhaust leaks near the oxygen sensor.
- Check engine grounds and related wiring.
- Verify that the engine reaches normal operating temperature.
- Check for other stored trouble codes.
- Test the oxygen sensor signal if equipment is available.
- Replace the oxygen sensor only after wiring and related causes have been considered.
Related codes
Related fuel-control and oxygen-sensor codes include:
Notes
The oxygen sensor must be hot enough to operate correctly. A cooling-system or thermostat problem that prevents normal operating temperature may affect closed-loop operation.
A Code 13 should be diagnosed as a circuit or signal problem, not simply as an automatic oxygen sensor replacement.