P2104: Throttle Actuator Control System - Forced Idle
A generic powertrain (engine and transmission) trouble code, same meaning on every brand.
It will barely drive at all - forced idle is the computer's strongest throttle intervention short of shutdown. Diagnose the companion codes before going anywhere.
Symptoms
- Engine held at idle regardless of pedal
- Reduced power warning
- Always accompanied by at least one other code
- Normal restart sometimes clears it temporarily
Likely causes, most common first
- Severe throttle actuator fault detected (see companion codes)
- Accelerator pedal sensor disagreement
- Throttle position sensor failure
- Wiring faults in the throttle or pedal circuits
Read P2104 yourself before paying for diagnosis
A basic Bluetooth OBD-II scanner ($20-40) plugs into the port under the dashboard and shows this code with live sensor data on your phone - useful both for confirming the fix and for talking to a shop from an informed position.
What is going on and how it gets diagnosed
P2104 is not a fault in itself - it is the computer's incident report. It says: a throttle or pedal problem serious enough was detected that the system locked the engine at idle to keep the car controllable. The actual culprit is named by the codes stored alongside it, and reading only P2104 tells you the punishment without the crime.
So the diagnostic value here is entirely in the companions: a pedal sensor code points at the pedal, a throttle position code at the throttle body, a communication code at wiring. Replacing parts because of P2104 alone is guesswork. One practical note - because forced idle latches for the current drive cycle on many cars, the engine may behave normally after a restart. That does not mean it healed; the underlying fault is still logged.
Repair options and cost
Typical US independent-shop ranges, parts and labor. Dealers run higher; regional labor rates vary.
Owner reports mentioning P2104
“On deceleration the engine stalls after driven for 10-15 minutes. The check engine light comes on. I don't notice the stall until I apply the gas pedal. A couple of times I was turning, I had to slow down severely to give me more time to turn( no power steering). I almost had an accident several times. The code was a throttle body code p2104.I replaced the throttle body. After a few months the stalling occurred again. This is dangerous. At this time the stalling hasn't happen very often but the code is still there, now I have to smog this vehicle. I see on the internet there have been other people with this condition.”2005 Ford F-250 · May 2019 · 116,000 mi
“My car wouldn't pick up speed then I receive a sudden thrust causing it to have a small jerk then takes off. Recently its been showing a ranch light know for throttle body issues code p2111 and p2104. This causes my car to stall in the middle of traffic especially on the highway which is a huge concern.”2005 Ford 500 · Jan 2018 · 144,000 mi
“Throttle control.car throttle will stop working at times.has stoped about 5times. It did stop working @ 55 mph with traffic behind us.had to pull over before getting hit.shut car off-restart ok for about a week.check for codes-had p2104 and p2111 stored.ford dealer sead throttle body needs replacing @ $434.38 plus labor.ford has recalls on other makes-but not mustang yet.I beleave they need to before someone gets hurt.”2010 Ford Mustang · Feb 2016 · 75,000 mi
Show 7 more owner reports
“While driving at low speeds the car has on several occasions surged forward and last week after starting the car the gas pedal was unresponsive and the "wrench" warning light came on. I restarted it and it seemed to be ok but the check engine light was on. I plugged in a code reader and it gave me error codes p2104 and p2112. I can't believe this isn't part of a recall based on the number of people it is affecting.”2008 Ford Fusion · Sep 2015 · 112,500 mi
“The engine died, meaning no acceleration. I restarted the engine after a rest and it started and drove again. It happened again later that day and I noticed that the rpms surged just before the engine died. I took it to autozone to get the codes from the computer, and the codes are p2111 and p2104. The throttle body is the likely defective part.”2006 Ford 500 · Jul 2015 · 187,000 mi
“Vehicle will not operate over 1,000 rpm. It had the throttle body cleaned on 15 aug 2013 under customer satisfaction recall 12n03. For the original complaint, the idling spiked where in this instance the car will not accelerate above 1,000 rpm. The codes associated with this incident are: p060b; p061b; p0122; p0155; p0222; p0316; p0480; p2104; p2110; p2122; p2127; p2132; p2135. *tr”2007 Ford Freestyle · Jan 2014 · 145,000 mi
“I had problems with the throttle sticking and I put my ob11 on and isaid code p2104 and p2111 .so icalled and they say its a well know problem.if you don't know what to do I can see some one get hurt so I think it should be a recall. *tr”2008 Ford F-150 · Dec 2013 · 64,000 mi
“For the past month the check engine light has appeared and stayed on for a brief time. Now it stays on . I have had a diagnostic test done and the results were p2112, p0721 and p2104. There appear to be a bad app sensor, throttle actuator control system-forced idle, stuck closed and failed ecm. If this is included in any recall, please let me know asap. This is the only vehicle I have and my lively-hood depends on it. *tr”2009 Ford Fusion · Oct 2013 · 108,252 mi
“I was driving at 55 mph when the car spuutered and lost all power. At that point the car would only idle which barely allowed me to pull off the road into a driveway. I turned it off and restarted. The car ran fine for a few miles then ,while turning off a main road the car lost all power and almost caused an accident. I turned it off and on again and was able to get it home. When I got home I checked it for codes and it brought up a p212 and p2104 code. I had the car towed to tracy ford where they replaced the throttle body at $690+/- plus labor. *tr”2005 Ford Five Hundred · Sep 2013 · 187,910 mi
“Tl* the contact owns a 2005 ford freestyle. The contact was driving 30 mph when the vehicle accelerated abnormally and independently. In addition, the vehicle would sporadically stall when the failure occurred. The contact was a mechanic and inspected the vehicle. He was able to generate failure codes that indicated throttle body failures. The vehicle had not been repaired. The failure and current mileages were 141,000. Updated 8/31/12 *cn the consumer stated with each failure the check engine light came on and when accessed through the obdii connector, p2104 tac forced to idle and p2111 tac system stuck open trouble codes, were presented. Updated 09/11/2012 *js”2005 Ford Freestyle · Jul 2012 · 141,000 mi
Cars that report P2104 most often
Based on mentions of this code in NHTSA owner complaints.
Frequently asked questions
Can I drive with P2104?
It will barely drive at all - forced idle is the computer's strongest throttle intervention short of shutdown. Diagnose the companion codes before going anywhere.
How much does it cost to fix P2104?
Typical US repair costs range from $100 for the simplest fix (diagnosis of the root-cause code) to $700 in the worst case. The right number depends on which cause your car has - see the causes list.
Related codes
The codes closest to P2104. They often appear together, and telling them apart is usually what narrows the diagnosis.
Definition per SAE J2012 standard nomenclature. Symptoms, causes and costs are editorial guidance - always confirm with a diagnosis of your specific vehicle.