P1409
Manufacturer-specific Basic entry
IAT - B Circuit Malfunction/ Exhaust Gas Recirculation Closed Position Performance
Severity
Medium
Typical repair cost
60 – 500 EUR
System
Powertrain
This is a manufacturer-specific code. Its exact meaning can differ between makes; the definition below follows the most common usage.
What it means
P1409 is stored when the IAT - B / Exhaust Gas Recirculation Closed Position signal is electrically valid but does not make sense compared with other sensors or the expected operating range. The circuit is usually fine; the component or what it measures is out of specification.
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Symptoms
- Check engine light on
- Rough or unstable idle
- Hesitation or poor acceleration
- Increased fuel consumption
- Possible limp mode with reduced power
Common causes
- IAT - B / Exhaust Gas Recirculation Closed Position worn, contaminated or out of calibration
- Mechanical problem in the system the sensor measures
- Air, vacuum or exhaust leak influencing the reading
- Wrong or low-quality replacement part
- Wiring resistance causing a small voltage offset
How to diagnose
- Compare the live IAT - B / Exhaust Gas Recirculation Closed Position reading with a known-good value or a second sensor at idle and at 2500 rpm
- Check for air, vacuum or exhaust leaks that could skew the reading
- Inspect the component for contamination and clean it if the design allows
- Verify the part number is correct for the engine
- Replace the IAT - B / Exhaust Gas Recirculation Closed Position if the reading remains out of specification
Frequently asked questions
Can I keep driving with P1409?
Usually yes for a short time, but expect reduced performance or higher fuel use. Have it diagnosed within a few days.
Will clearing P1409 fix it?
No. Clearing only erases the stored code; it returns as soon as the monitor runs again unless the cause is repaired.