What it means
The diesel intake throttle position sensor does not reach the calibrated minimum or maximum stop value during a self-test sweep — typically sensor wear, mechanical stop misalignment, or a sticky throttle plate.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
The diesel intake throttle plate regulates airflow into the engine, and its position sensor reports how far the plate has moved. During a self-test, the control module checks whether the sensor reaches both calibrated end positions; this code sets when one or both stop readings are outside the expected range.
Common causes
Most likely first.
- Intake air flow position sensor fault
- Throttle plate or actuator not reaching its stop
- Mechanical stop or linkage misadjusted
- Throttle plate sticking from deposits
Symptoms
- Reduced engine power or sluggish acceleration
- Rough or uneven engine response
- Poorer fuel economy
How to diagnose it
- Record freeze-frame data and compare commanded throttle position with the sensor reading during a self-test or commanded sweep to see which end position is missed.
- With the engine off, inspect the throttle plate and linkage for deposits, damage, binding, or anything preventing full travel.
- Check the position sensor connector and wiring for loose, corroded, damaged, or chafed connections that could distort the reported position.
- If the plate moves freely, use a scan tool to compare sensor output throughout its travel and look for a dead spot or inconsistent reading.
- Test the sensor and actuator circuits and verify mechanical stop alignment against the manufacturer's specification before replacing parts.
Common fixes
- Clean deposits that are restricting throttle plate movement, using an appropriate procedure.
- Repair loose, damaged, or corroded sensor or actuator wiring and connectors.
- Replace a faulty intake throttle position sensor.
- Correct a misaligned mechanical stop or linkage according to the manufacturer's procedure.
- Repair or replace a throttle actuator that cannot move the plate through its full range.
Can I keep driving?
If the engine runs smoothly and power remains adequate, drive gently only as needed to reach a repair location. Reduced airflow control can worsen response and fuel economy, so avoid hard acceleration or towing.
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.