MAP/MAF - Throttle Position Correlation
The ECU knows how much air should go in for each throttle opening and compares it with what the air flow meter or the manifold pressure sensor measures.
What the car has detected
More or less air goes in than the throttle position should allow: there is usually an air leak or a dirty sensor.
The car may idle roughly, jerk or go into limp mode. Have it checked soon.
Symptoms
- Engine or EPC warning light on
- Rough idle
- Loss of power or limp mode
Possible causes
- Air leak in a hose, the manifold or the crankcase breather
- Dirty or faulty throttle body
- Faulty air flow meter or manifold pressure sensor
- Oil filler cap not shut properly or a worn seal
Checks for the garage
- Check the oil filler cap is shut properly
- Look for leaks in the hoses and the intake manifold
- Clean the throttle body and run its adaptation
Next step
Ask for air leaks to be found, the throttle body cleaned and the air flow meter or pressure sensor checked.
Go to a garage in the next few days. Reading the live data needs a diagnostic tool.