P01F5 code meaning
O2 Sensor Circuit No Activity Detected Bank 1 Sensor 4
Powertrain system Generic code P01xx codes Check engine light
What P01F5 means
Sensor 4 on bank 1 is a fourth oxygen sensor, downstream of a further converter. No manufacturer or vehicle using sensor 4 codes could be identified (GM and Ford documents stop at sensor 3); the description follows CARB's requirements for downstream sensors and GM's checks on sensor 2. P01F5 means that with a warm engine and heated sensor the signal does not switch between rich and lean but stays in the middle or at the bias voltage the module applies. For sensor 2, GM detects this when the signal stays above 1.7 V of a 1.9 V bias, a two-trip fault. Usual causes are an open signal or ground wire or a dead sensor.
P01F5 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modeNot expected
- Repair difficultyEasy, DIY possible
- Typical labor0.5 to 1.5 hours
- Clears after repairAfter a drive cycle
Symptoms of P01F5
- Check engine light on (usually after two drive cycles)
- Catalyst monitor readiness possibly not set
- Usually no change in driving
Common causes of P01F5
- Most likelySignal or ground wire open, connector corroded
- PossibleSensor aged or poisoned, produces no voltage
- PossibleSensor heater faulty, sensor does not reach operating temperature
- Less likelyExhaust leak upstream of the sensor
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Oxygen sensor bank1 sensor4Oxygen sensor wiringCatalytic converter
What each part of P01F5 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 1 | Area: fuel and air metering. |
| F5 | The exact fault in that area. |
What to do next
- Note P01F5 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P01F5
What does P01F5 mean?
P01F5 means "O2 Sensor Circuit No Activity Detected Bank 1 Sensor 4". Sensor 4 on bank 1 is a fourth oxygen sensor, downstream of a further converter. It is a generic code, so it means the same on every make.
Is it safe to drive with P01F5?
Usually yes, for a short time, if the check engine light is steady and the car drives normally. If the light flashes or the car runs badly, stop and have it checked.
Will P01F5 fail an emissions test?
Yes, it can. P01F5 is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P01F5 to fix?
Difficulty: easy. A typical repair takes 0.5 to 1.5 hours of work. A careful DIY repair is possible with basic tools and a scanner.
Will P01F5 clear itself after the repair?
After the repair the car has to complete a drive cycle (a mix of city and highway driving) before the test runs again. Until then the readiness monitor shows "not ready", which can fail an inspection.