P2104
Throttle Actuator Control System - Forced Idle
- Severity
- Critical
- Driving
- Drive only to a garage
The module has forced the engine to idle. It found a fault it considers serious enough that it will not let the throttle open beyond idle, so the car will move barely or not at all. This is the protection working, not the fault itself.
Possible causes
- CommonAnother throttle or pedal fault already stored - this code is the module's response to it
- CommonThrottle or pedal position sensor disagreement
- CommonCarbon making the throttle plate stiff
- CommonWiring or connector fault on a throttle or pedal circuit
- PossibleLow or unstable supply voltage
- PossibleFailed throttle actuator control module
What you might notice
- Sudden loss of power - reduced-power mode
- Engine will not rev beyond a low limit
- Rough or unstable idle
- Warning light for reduced engine power
- Engine may not start
What to check, in order
- The car may be unable to move under its own power. Arrange recovery rather than trying to coax it along in traffic.
- Read all codes. This one records what the module did, not what went wrong - the fault that triggered it is stored alongside, and that is the one to diagnose.
- Check battery voltage and the earth connections. An unstable supply produces sensor disagreements that look like component failures.
- Inspect the throttle body for carbon and the connectors for corrosion.
- Compare commanded against actual throttle position on the live data screen.
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