What it means
The ECM detects a circuit intermittent/erratic fault on the turbocharger interstage pressure sensor a circuit. 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
- The engine or gearbox may go into limp mode
How it works
Turbocharger interstage pressure Sensor A measures pressure between turbocharger stages, and the ECM uses its signal to regulate boost. P2D25 sets when that signal jumps, drops out, or varies erratically instead of remaining consistent with operating conditions, often because a connection or ground is intermittent.
Common causes
Most likely first.
- Sensor connector not seated
- Noisy ground reference
- Connector with intermittent contact under vibration
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
- Review freeze-frame data and scan-tool history, then watch Sensor A's live reading for sudden dropouts or jumps as conditions change.
- Inspect Sensor A's connector for an incomplete latch, loose terminals, corrosion, or moisture.
- Follow the Sensor A harness and look for chafing, strain, heat damage, or sections that move against nearby parts.
- Check the sensor ground and signal continuity against the manufacturer's specification while gently moving the harness to reveal intermittent contact.
- If the circuit remains stable, monitor Sensor A's output under the conditions that triggered the code and replace it only if its signal is erratic.
Common fixes
- Fully seat and secure Sensor A's connector.
- Clean or repair loose or corroded connector terminals.
- Repair chafed Sensor A wiring or a poor ground connection.
- Replace Sensor A if it continues to produce an erratic signal with a sound circuit.
Can I keep driving?
Power may drop suddenly if the fault returns, so avoid overtaking, hard acceleration, and towing until it is diagnosed. If the engine enters limp mode or loses substantial power, pull over where safe.
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.