P0241
Turbo/Supercharger Boost Sensor B Circuit Low
When a vehicle powertrain module registers the fault code P0241, it points directly to an internal system malfunction identified as "Turbo/Supercharger Boost Sensor B Circuit Low". Operating your engine under this condition may degrade long-term fuel maps.
Driver's Summary
When your OBD2 scanner shows P0241, the engine control module has flagged an issue specifically related to turbo/supercharger boost sensor b circuit low. On the road, this usually shows up as significant power loss, whistling noise, limp mode. Stop driving as soon as it is safe to do so. This fault can lead to expensive secondary damage if left unaddressed.
Symptoms
Significant power loss, whistling noise, limp mode
Common Causes
- Short to ground in boost sensor circuit
- Failed Boost Sensor B
- Massive boost leak
- Faulty wastegate
How to Fix
- 1 Repair shorted sensor wire
- 2 Replace boost sensor
- 3 Tighten intercooler pipes
- 4 Repair wastegate
Technical Explanation
The PCM triggers P0241 after its internal monitoring routine detects that a specific circuit or sensor has exceeded its acceptable operating range. The PCM monitors crankshaft rotational velocity via the CKP sensor at a resolution of individual tooth gaps on the reluctor ring. A combustion event in each cylinder produces a measurable acceleration spike; its absence or weakness is flagged as a misfire event within a 200-revolution or 1000-revolution test window. Once confirmed, the code is stored as a permanent DTC and the MIL is activated. The freeze frame snapshot — recording RPM, load, coolant temperature, and fuel trim at fault detection — is also saved and is critical for accurate diagnosis.
Is It Safe to Drive?
This fault carries real mechanical risk. The root causes — including short to ground in boost sensor circuit — can trigger a chain reaction of component failures if the vehicle continues to be driven. Have it towed or drive directly to a shop without delay.
Mechanic's Pro Tip
The most common mistake with P0241 is replacing the sensor without verifying the reference voltage and ground integrity first. Use a scan tool to monitor the sensor's live output; a truly failed sensor shows a stuck, flatlined reading — a sensor that fluctuates but reads slightly off usually indicates a wiring or vacuum issue, not a dead sensor. Always spray electrical contact cleaner on the connector pins before condemning the sensor.
Pipe reattachment: 50 - 100; Sensor: 100 - 200