What it means
The ECM detects a circuit low fault on the turbocharger/supercharger a temperature sensor. Reading cannot be used reliably for control.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
Turbocharger or supercharger A’s temperature sensor sends a signal to the engine control module so it can account for heat in the forced-induction system. P2B6F sets when that signal is lower than expected, commonly because the signal wire is shorted to ground, the sensor is internally shorted, or a connector has excessive resistance.
Common causes
Most likely first.
- Signal wire shorted to ground
- Internal sensor short
- Connector pins corroded - high contact resistance
Symptoms
- Check engine light on
- Significant power loss / limp mode
- Possible blue or black smoke from exhaust
- Whistling or hissing sound from intake
How to diagnose it
- Record freeze-frame data and check the live sensor A temperature reading for an implausibly low value under the recorded conditions.
- Inspect sensor A’s connector and wiring for a signal wire rubbed through to ground, corrosion, or loose terminals.
- Check the sensor circuit’s signal, reference, and ground using the wiring diagram and manufacturer’s specification.
- With the sensor disconnected, determine whether the low signal remains in the harness; test for a short to ground before condemning the sensor.
- If the harness checks out, test sensor A for an internal short and compare its output with the manufacturer’s specification.
Common fixes
- Clean and secure corroded or loose sensor A connector terminals.
- Repair the signal wire if it is shorted to ground or damaged.
- Repair a poor connector contact that is pulling the reading low.
- Replace turbocharger or supercharger A’s temperature sensor if it is internally shorted.
Can I keep driving?
Avoid hard acceleration and boost while the reading is unreliable, particularly if power is reduced, smoke appears, or the intake hisses. Continued use can leave the engine control module without dependable temperature information for forced-induction protection.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.