P0138
P0138 means "O2 Sensor Circuit High Voltage (Bank 1 Sensor 2)". Severity: 🟢 Low. Usually safe to drive in the short term, but get it checked soon.
What the P0138 code means
| Code | P0138 |
| Definition | O2 Sensor Circuit High Voltage (Bank 1 Sensor 2) |
| System | Powertrain (engine & transmission) |
| Type | Generic (SAE standard) |
| Subsystem | Fuel & Air Metering |
| Severity | 🟢 Low |
Common causes of P0138
- Failed downstream O2 sensor
- Wiring short
- Contamination
How to fix P0138
- Replace downstream O2 sensor
- Inspect wiring
Always confirm the diagnosis with a scan tool and live data before replacing parts.
Is it safe to drive with P0138?
Usually safe to drive in the short term, but get it checked soon.
P0138, answered.
What does P0138 mean?
P0138 stands for "O2 Sensor Circuit High Voltage (Bank 1 Sensor 2)". It is a generic (sae standard) OBD-II powertrain trouble code.
Is it safe to drive with a P0138 code?
Usually safe to drive in the short term, but get it checked soon.
What causes P0138?
Common causes include: Failed downstream O2 sensor; Wiring short; Contamination.
How do you fix P0138?
Typical fixes: Replace downstream O2 sensor; Inspect wiring. Always confirm the diagnosis before replacing parts.