P2172
Throttle Actuator Control System - Sudden High Airflow Detected
- Severity
- High
- Driving
- Drive only to a garage
The module has measured suddenly more airflow than the throttle position should allow. Air is getting into the engine that the throttle plate is not admitting - most often through a leak downstream of the throttle, or because carbon has changed what a given plate angle means.
Possible causes
- CommonAir leak in the intake system
- CommonCarbon on the throttle plate, so actual airflow does not match the commanded position
- CommonFaulty mass airflow sensor
- CommonThrottle position sensor drift
- PossibleBlocked air filter or restricted intake
- PossibleVacuum hose disconnected or split
What you might notice
- Reduced power mode
- Hesitation or surging
- Rough idle
- Worse fuel economy
- Check engine light on
What to check, in order
- Check for intake leaks and disconnected vacuum hoses. Air the module has not accounted for is the most common reason measured airflow disagrees with throttle position.
- Inspect the throttle body for carbon, which changes how much air a given plate angle admits.
- Compare the mass airflow reading against the throttle position on the live data screen through an acceleration.
- Check the air filter and intake ducting.
- Read all codes - throttle position or MAF codes alongside this one name the component.
Read this code from your own car
Plug an ELM327 adapter into the OBD-II port under the dashboard. Pin16 reads every stored, pending and permanent code, explains each one like this page does — offline, with no account — and shows what the car recorded when the fault was set.
Where this code sits
P00xxP01xxP02xxP03xxP04xxP05xxP06xxP07xxP08xxP09xxP0AxxP0BxxP0CxxP0DxxP0ExxP0FxxP10xxP11xxP12xxP13xxP14xxP15xxP16xxP17xxP18xxP19xxP1AxxP1BxxP1CxxP1DxxP1ExxP1FxxP20xxP21xxP22xxP23xxP24xxP25xxP26xxP27xxP28xxP29xxP2AxxP2BxxP2CxxP2DxxP2ExxP2FxxP30xxP31xxP32xxP33xxP34xxP35xxP36xxP37xxP38xxP39xxP3AxxP3BxxP3CxxP3DxxP3ExxP3Fxx
Fuel and air metering
P2100P2101P2102P2103P2104P2105P2106P2107P2108P2109P2110P2111P2112P2113P2114P2115P2116P2117P2118P2119P2120P2121P2122P2123P2124P2125P2126P2127P2128P2129P2130P2131P2132P2133P2134P2135P2136P2137P2138P2139P2140P2141P2142P2143P2144P2145P2146P2147P2148P2149P2150P2151P2152P2153P2154P2155P2156P2157P2158P2159P2160P2161P2162P2163P2164P2165P2166P2167P2168P2169P2170P2171P2172P2173P2174P2175P2176P2177P2178P2179P2180P2181P2182P2183P2184P2185P2186P2187P2188P2189P2190P2191P2192P2193P2194P2195P2196P2197P2198P2199