P2104: Throttle control system: forced idle
The ECU has held the engine at idle because it has found a fault in the electronic throttle system. The real fault is usually in another stored code.
| Code | P2104 |
|---|---|
| System | Engine and transmission |
| Group | P21xx, Throttle, injection and emissions |
| Type | Generic: it means the same on every make |
| Can you keep driving? | Better not |
What P2104 means
When the ECU detects a serious fault in the electronic accelerator (pedal, throttle or its control), it protects itself by putting the engine into a safety mode. This code is not the fault itself: it tells you the ECU has held the engine at idle and is ignoring the pedal. The real cause usually shows up as another code stored at the same time.
Most common causes
- Another code stored at the same time, which is the real explanation (pedal or throttle sensors, throttle motor)
- Loose or corroded throttle body or pedal connector
- Carbon on the throttle plate slowing it down
- Low battery voltage or loose battery terminals
- A faulty pedal sensor or throttle body
- A fault in the engine ECU, which is uncommon
Symptoms
- Engine or throttle warning light on
- The engine stays at idle even when you press the pedal
- The car barely moves
Can you drive with P2104?
Better not With the engine stuck at idle there is not enough power to drive safely in traffic. Pull over somewhere safe and call for assistance or move it to a garage carefully.
Open the bonnetthe in-depth explanation
How to check it
Read every stored code, not just this one, and note them down before clearing anything: the other code tells you which part is at fault. If only this one appears, check the battery and the pedal and throttle connectors.
How to read and clear P2104 with Final OBD
Plug an OBD2 scanner in under the steering wheel, switch the ignition on and open Final OBD. Under Faults you’ll see P2104 with its description and whether it’s confirmed, pending or permanent.
If the engine stores it over standard OBD, with FREE you read this code with its explanation for nothing and clear it. With PRO you also read the faults of every control unit and clear them in all of them.
Clearing the code only turns the light off: if the cause is still there, it comes back. Clear it once it’s fixed, and not right before an inspection. It’s all in how to read and clear fault codes and in inspections and OBD.
Similar codes
- P2100 Throttle actuator A control motor circuit open
- P2101 Throttle actuator A control motor circuit range or performance
- P2102 Throttle actuator A control motor circuit low
- P2103 The throttle actuator A control motor gives a higher signal than normal
- P2105 Throttle control system: forced engine shutdown
- P2106 Throttle control system: forced limited power
- P2107 Throttle actuator control module processor fault
- P2108 Throttle actuator control module performance
- P2110 Throttle control system: forced limited RPM
- P2111 Throttle control system stuck open
- P2112 Throttle control system stuck closed
- P2118 Throttle actuator control motor current range or performance
What does code P2104 mean?
When the ECU detects a serious fault in the electronic accelerator (pedal, throttle or its control), it protects itself by putting the engine into a safety mode. This code is not the fault itself: it tells you the ECU has held the engine at idle and is ignoring the pedal. The real cause usually shows up as another code stored at the same time.
Can you drive with P2104?
With the engine stuck at idle there is not enough power to drive safely in traffic. Pull over somewhere safe and call for assistance or move it to a garage carefully.
How do you clear P2104?
With an OBD2 scanner and an app like Final OBD, which clears it for free if it’s stored by the engine control unit. But clearing it only turns the light off: if the cause isn’t fixed, P2104 comes back.
Read it on your car
Final OBD reads and clears engine faults through standard OBD for free, each one explained in plain English. With PRO it also reads the faults of every control unit, each make’s own codes included, and clears them in all of them.
