P1146moderate severityPowertrain
Mass Air Flow Sensor Malfunction
on 2002 Mercedes-Benz SL 3.0L I6 · RWD
What this code means
The ECU detected that the MAF sensor signal is erratic or outside the expected range for current engine operating conditions. The MAF sensor is critical for accurate fuel metering on Mercedes-Benz engines.
Symptoms
- Check Engine Light
- Poor acceleration
- Rough idle
- Black smoke
- Stalling
Common causes
- Dirty or contaminated MAF sensor element
- Air leak in intake tract after MAF
- Faulty MAF sensor
- Damaged wiring or connector
- Intake boot torn
Diagnostic steps
- Clean MAF sensor with approved MAF cleaner
- Inspect intake boot and clamps for air leaks
- Monitor MAF readings vs specifications
- Test sensor wiring and connector
- Compare readings at idle and 2500 RPM
Repair notes
Clean the MAF sensor first; replace if readings remain out of specification.
Other Powertrain codes on this vehicle
P0001
Fuel Volume Regulator Control Circuit/Open
P0002
Fuel Volume Regulator Control Circuit Range/Performance
P0003
Fuel Volume Regulator Control Circuit Low
P0004
Fuel Volume Regulator Control Circuit High
P0010
Intake Camshaft Position Actuator Circuit/Open Bank 1
P0011
Intake Camshaft Position Timing Over-Advanced Bank 1
P0012
Intake Camshaft Position Timing Over-Retarded Bank 1
P0013
Exhaust Camshaft Position Actuator Circuit/Open Bank 1
P0014
Exhaust Camshaft Position Timing Over-Advanced Bank 1
P0015
Exhaust Camshaft Position Timing Over-Retarded Bank 1