OBD2 Car ScannerWhat does P2174 mean?
P2174 stands for Throttle Actuator Control System - Sudden Low Air Flow Detected. The engine computer has found a problem with how fuel and air are measured or mixed. This affects fuel economy, emissions and sometimes how smoothly the engine runs.
Powertrain codes cover the engine, transmission and emissions. When the car's computer sees a reading outside its normal range, it stores this code and may turn on a warning light on the dashboard.
Common causes
- Vacuum or intake air leaks
- Dirty or faulty mass airflow (MAF) sensor
- Faulty oxygen sensor or its wiring
- Fuel pressure problems (pump, filter or regulator)
- Clogged or leaking fuel injectors
What to do
- Read all stored and pending codes with a scanner. Several codes together often point to one cause.
- Note the freeze frame data (speed, temperature, load) recorded when the code was set.
- Inspect the wiring and connectors of the part named in the code for damage, corrosion or looseness.
- Fix the most likely and cheapest cause first, then clear the code and drive to see if it comes back.
Read this code from your own car
Plug in a cheap ELM327 adapter and the app shows every fault code, what it means and how to fix it.
Frequently asked questions
What does P2174 mean?
P2174 means “Throttle Actuator Control System - Sudden Low Air Flow Detected”. It belongs to the fuel and air metering group: The engine computer has found a problem with how fuel and air are measured or mixed. This affects fuel economy, emissions and sometimes how smoothly the engine runs.
Is it safe to drive with P2174?
You can usually drive carefully for a short time, but fix it soon to avoid further damage or higher fuel use.
How do I clear P2174?
Fix the cause, then clear the code with an OBD2 scanner or app. If the fault is still there, the code will come back.
Related codes
- P216EFuel Injector Group F Supply Voltage Circuit Low
- P216FFuel Injector Group F Supply Voltage Circuit High
- P2172Throttle Actuator Control System - Sudden High Air Flow Detected
- P2173Throttle Actuator Control System - High Air Flow Detected
- P2175Throttle Actuator Control System - Low Air Flow Detected
- P2176Throttle Actuator Control System - Idle Position Not Learned
- P2177System Too Lean Off Idle Bank 1
- P2178System Too Rich Off Idle Bank 1
Code meanings can vary by manufacturer. This page is general guidance, not a repair manual. Always confirm the cause before replacing parts.