P1247

What it means

P1247 is a manufacturer-specific code that, in this guide, means Turbo Boost Pressure Low. The engine control unit compares actual boost pressure from the boost or manifold pressure sensor with the target boost for the current load and speed. It set the code because actual boost stayed below target for longer than the allowed time. The exact test conditions vary by manufacturer and engine, so check the model-specific data.

Symptoms

• Noticeable loss of power, especially under load or when overtaking
• Engine warning light on, and possibly limp mode
• Poor or slow throttle response
• Whistling, hissing or fluttering noises from the intake side during acceleration
• Black or grey smoke from the exhaust on diesels
• Higher fuel consumption

Possible causes

• Boost leak from a split, loose or disconnected charge air hose, intercooler or connectionlikely
• Boost control actuator, wastegate or variable geometry mechanism sticking, or its vacuum or electrical control faultylikely
• Boost control solenoid, or its vacuum or pressure lines, cracked, blocked or leakingpossible
• Faulty or contaminated boost or manifold pressure sensor giving a false low readingpossible
• Worn or damaged turbocharger (shaft play, damaged blades, oil leakage into the compressor)possible
• Restricted air intake or exhaust (blocked air filter, clogged particulate filter or catalyst, collapsed duct)possible
• Wiring or connector fault in the sensor or actuator circuits, or a fault in the control unitrare

How to diagnose

1. Read all stored and pending codes and the freeze frame data to see engine speed, load and temperature when the fault set. Fix any related codes first.
2. Visually inspect the air filter, intake ducting, charge air hoses, clamps and intercooler for splits, oil residue, looseness or damage.
3. Inspect the wiring and connectors to the boost pressure sensor, boost control solenoid and actuator for damage, corrosion or chafing.
4. Compare actual and requested boost in live data during a road test or loaded run, noting where the shortfall occurs.
5. Pressure or smoke test the charge air system to find leaks, following the model-specific test pressure.
6. Check that the actuator or wastegate rod moves freely and responds to commanded changes, using vacuum or electrical tests suited to the system. Also check the solenoid and its lines.
7. Check the boost sensor reading against a known reference with the engine off and at load. Check for restriction in the exhaust or particulate filter, for example by measuring back pressure.
8. Check the turbocharger for excessive shaft play, damaged blades and oil in the intake, following the manufacturer's limits.

How to fix

• Repair or replace leaking, split or loose charge air hoses, clamps or intercooler.
• Free, repair or replace a sticking actuator, wastegate or variable geometry mechanism, and fix its control lines or solenoid.
• Replace a faulty boost pressure sensor or repair the wiring and connectors.
• Replace a blocked air filter and clear or repair intake or exhaust restrictions, including a blocked particulate filter or catalyst.
• Repair or replace a worn or damaged turbocharger, and find out why it failed, such as oil supply or contamination problems.
• Apply a manufacturer calibration update only if one is published for this fault.

Can I keep driving?

This code for other makes

• P1247AcuraAccelerator Position Sensor 2 Circuit Malfunction
• P1247FordTurbo Boost Pressure Low
• P1247HondaAccelerator Position Sensor 2 Circuit Malfunction
• P1247InfinitiAccelerator Position Sensor 2 Circuit Malfunction
• P1247LincolnTurbo Boost Pressure Low
• P1247MercuryTurbo Boost Pressure Low
• P1247VolkswagenNeedle Lift Sensor Circuit Open/Short To B+

Nearby codes

• P1246OtherAlternator Load Input Failed
• P1248OtherTurbo Boost Pressure Not Detected