What it means
The ECM detects a circuit low fault on the throttle valve intake air pressure sensor 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
The throttle valve intake air pressure sensor measures pressure in the intake passage at the throttle valve, and the ECM uses its signal to help control engine airflow. This code sets when the sensor circuit signal is too low, which can result from a short to ground, a sensor fault, or wiring trouble.
Common causes
Most likely first.
- Signal circuit shorted to ground
- Sensor internal fault
- Wiring or connector fault
Symptoms
- Check-engine light
- Rough idle or hesitation
- Reduced engine power
How to diagnose it
- Save freeze-frame data and check the live sensor signal to confirm it is abnormally low compared with other intake readings.
- Inspect the throttle valve intake air pressure sensor connector and harness for a signal wire shorted against ground, damaged insulation, corrosion, or loose pins.
- Check the sensor port or pressure passage for blockage that might affect the reading, while keeping in mind that this code concerns a low circuit signal.
- Test the reference supply, ground, and signal circuit for shorts to ground or poor connections using the manufacturer's specification.
- If the wiring passes, test the sensor output under changing intake conditions before replacing the sensor.
Common fixes
- Repair a signal wire shorted to ground or damaged harness insulation.
- Clean and secure corroded or loose terminals at the sensor connector.
- Clear a blocked sensor port or restore a damaged pressure passage if inspection identifies one.
- Replace the sensor if its output remains low with a verified circuit.
Can I keep driving?
If the engine runs roughly or power is reduced, limit driving to a short trip and avoid fast traffic or hard acceleration. The ECM may not control airflow reliably, and the vehicle can hesitate or lose power.
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.