P2D24: Turbocharger Interstage Pressure Sensor A Circuit High

What it means

The ECM detects a circuit high 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 for the ECM's boost calculations. P2D24 sets when the Sensor A circuit signal is higher than the ECM expects; a signal shorted to battery voltage, an open sensor, or a poor connection can cause this high reading.

Common causes

Most likely first.

1. Signal wire shorted to B+
2. Open sensor
3. 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

1. Check freeze-frame data and Sensor A live data for a reading stuck high, and note whether it changes with engine load.
2. Inspect Sensor A's harness for damaged insulation, contact with a power source, or chafing near hot or moving components.
3. Check the Sensor A connector for backed-out, corroded, or loose pins that could interrupt the circuit.
4. Using the wiring diagram, test the signal circuit for a short to battery voltage and check sensor supply, ground, and continuity against the manufacturer's specification.
5. If the wiring checks pass, test Sensor A for an internal open or failed output before replacing it.

Common fixes

• Repair a Sensor A signal wire shorted to battery voltage.
• Restore a loose or corroded Sensor A connector connection.
• Replace Sensor A if testing confirms an internal open or failed output.
• Clear the code and verify Sensor A tracks pressure changes.

Can I keep driving?

Avoid heavy acceleration and towing if the vehicle has reduced power, as the ECM may limit boost or use unreliable pressure data. Arrange diagnosis promptly, and stop if severe power loss or heavy smoke occurs.