P2104 Throttle actuator control system - forced idle
OBD2 Error Codes

P2104 Throttle actuator control system - forced idle

26.05.2022 /

P2104 Throttle actuator control system - forced idle

OBD-II DTC Datasheet

Throttle Actuator Control System - Forced Idle

What does this mean?

This Generic Powertrain Diagnostic Trouble Code (DTC) typically applies to all OBD-II equipped vehicles that use a wired throttle control system, including but not limited to Ford, GM, Toyota, Dodge, Chevy, Subaru, etc. Ironically, this code seems to be much more common on Ford vehicles compared to other brands.

The P2104 OBD-II DTC is one of the possible codes that indicates that the powertrain control module (PCM) has detected a malfunction and is restricting the throttle actuator control system.

This situation is known as activating failsafe or braking mode to prevent the motor from accelerating until the fault is corrected and the associated code is cleared. There are four codes, called force codes, and they are P2104, P2105, P2106 and P2110.

The PCM sets them when other codes are present that indicate a problem that could be safety related or cause damage to the engine or transmission components if not corrected in a timely manner.

P2104 is set by the PCM to force the throttle actuator control system to remain idling.

This code may be related to a malfunction in the throttle actuator control system, but usually setting this code is associated with another problem. DTC P2104 is triggered by the PCM when it receives an abnormal signal from various components. The throttle actuator control system is a duty cycle controlled by the PCM and system function is limited when other DTCs are detected.

Code severity and symptoms

The severity of this code can be medium to severe depending on the specific problem. Symptoms of a P2104 DTC may include:

  • The engine will not start
  • Poor throttle response or no throttle response
  • Check Engine light is on
  • Backlit ABS light
  • Automatic transmission does not shift
  • Additional codes are present

Common Causes of This DTC

The most common situations in which this code is installed and put into failsafe or fallback mode to indicate a problem and act as a red flag:

  • Engine overheating
  • Coolant leaks
  • Exhaust gas recirculation valve defective
  • Malfunction of the MAF sensor
  • Drive axle modifications
  • ABS, traction control or stability system failures
  • Automatic transmission problems
  • Abnormal system voltages

What are the general repairs?

  • Repair the coolant leak
  • Replacing or cleaning the ABS sensor
  • Replacing or cleaning the exhaust gas recirculation valve
  • Replacing or Cleaning the MAF Sensor
  • Cleaning connectors from corrosion
  • Repair or replacement of wiring
  • Flashing or replacing PCM

Diagnostic and repair procedures

The first step in troubleshooting any problem is to review the vehicle-specific Technical Service Bulletins (TSBs) by year, model, and powerplant. In some cases, this can save you a lot of time in the long run by pointing you in the right direction.

The second step for this code is to complete a PCM scan to determine other trouble codes. This code is informational and in most cases the function of this code is to alert the driver that the PCM has initiated a failover due to a fault or failure in a system that is not directly connected to the throttle control actuator.

If other codes are found, you should check the TSB associated with the specific vehicle and that code. If the TSB has not been generated, you must follow the specific troubleshooting steps for this code to pinpoint the exact source of the fault that the PCM detects in order to put the engine into failsafe or fail-safe mode.

Once all other codes have been cleared, or if no other codes are found, if the throttle actuator code still exists, the PCM and the throttle actuator must be evaluated. As a starting point, visually inspect all wiring and connections for obvious defects.

General error

Replacing the throttle control actuator or PCM when other faults set this code.

Rare repair

Replace the throttle actuator control

Hopefully the information in this article has helped point you in the right direction for resolving the force code problem of your throttle actuator control system. This article is for informational purposes only and specific technical data and service bulletins for your vehicle should always take priority.

External links

Here are links to some discussions on Ford cars with code P2104:

  • 05 F150 5.4 error codes P2104 and P2112 throttle valve problems
  • TAC system forced idle 2104 stuck open 2112
  • P2104 Trouble Code ??
  • DTCs P2104 and P2111

Related DTC discussions

  • 2006 Ford Expedition 5.4L P0121, P2104 and P2112So my friend has something that the new 2006L 5.4 Ford Expedition produces three codes. The car has 92,072 miles. These are PO121, P2104 and P2112. So what should I do about it? Anyone who has had these codes before. How did you solve the problem…. 
  • P2104-2005 F250 SD 4X4 5.4 Triton 3 valvesThe truck went into stalemate last week. Replace the throttle body with a new throttle control actuator. I've had this problem every 2 years since 2010. In the past, it appeared to be related to the throttle actuator control valve on the throttle body. This time the problem persisted. Now at a loss. Any ideas? ... 

Need more help with your p2104 code?

If you still need help with DTC P2104, post a question in the comments below this article.

NOTE. This information is provided for informational purposes only. It is not intended to be used as a repair recommendation and we are not responsible for any action you take on any vehicle. All information on this site is protected by copyright.

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