What causes GM code 13?

Aged or contaminated oxygen sensor with a lazy signal Open sensor signal wire or corroded connector Exhaust leak near the sensor drawing in air Sensor heater fault on heated sensor models

How do I fix GM code 13?

Retrieve codes with a paperclip across ALDL pins A and B before starting work Watch sensor voltage with a scan tool and confirm it stays fixed near 0.4 volts Inspect wiring and ground connections for opens and corrosion Repair exhaust leaks ahead of the sensor first Replace the sensor only after wiring and leaks test good

13 Oxygen Sensor Circuit Open Or No Activity

Q: What does GM code 13 mean?

GM code 13 — Oxygen Sensor Circuit Open Or No Activity. Applies to 1982-1995 GM cars and C/K trucks, Camaro, Corvette.

Make: GM (1982-1995)
Category: Powertrain - Fuel/Air Metering
Severity: Check Engine Light
Applies to: 1982-1995 GM cars and C/K trucks, Camaro, Corvette

How to read it

Code 13 reads as 1 flash, pause, 3 flashes on the check-engine light. Jump terminals A and B on the ALDL connector with the key off, then turn the key on with the engine off and count the check-engine flashes.

What does GM code 13 mean?

13 — Oxygen Sensor Circuit Open Or No Activity. This code sets when your vehicle computer detects oxygen sensor circuit open or no activity.

Common causes of 13

Aged or contaminated oxygen sensor with a lazy signal
Open sensor signal wire or corroded connector
Exhaust leak near the sensor drawing in air
Sensor heater fault on heated sensor models

How to fix 13

Retrieve codes with a paperclip across ALDL pins A and B before starting work
Watch sensor voltage with a scan tool and confirm it stays fixed near 0.4 volts
Inspect wiring and ground connections for opens and corrosion
Repair exhaust leaks ahead of the sensor first
Replace the sensor only after wiring and leaks test good