How much does it cost to fix P2104?

DIY repair typically costs $50–$400 for parts. Professional repair runs $200–$1200 including parts and labor.

P2104

Powertrain

High

Throttle Actuator Control System — Forced Idle

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The P2104 code indicates that the powertrain control module (PCM) has forced the engine into an idle-only state as a safety measure. This is not a fault code in the traditional sense — it's a protective response code. The PCM sets P2104 when it detects another problem in the throttle control system that could be dangerous if the engine were allowed to accelerate normally.

When P2104 is active, your engine will only idle — pressing the gas pedal will have no effect. This 'forced idle' mode is designed to prevent unintended acceleration and protect both the driver and the engine. The vehicle is essentially undrivable in this state, though the engine will continue to run at idle.

The critical step in diagnosing P2104 is to look for other stored trouble codes. P2104 is always triggered by another underlying problem — commonly a faulty throttle position sensor, electronic throttle body issue, or accelerator pedal position sensor failure. Fix the root cause code first, then clear P2104. Do not attempt to drive the vehicle in this condition; have it towed to a repair facility for proper diagnosis.

Severity

High — Immediate AttentionWithin 24 Hours

Symptoms

•Check engine light on
•Engine stuck at idle speed and will not accelerate
•No throttle response when pressing the gas pedal
•Vehicle may display additional warning lights (ABS, traction control)
•Engine may run rough at forced idle

Likely Causes

Underlying throttle system fault triggering forced idle as a safety response40%

P2104 is a 'companion' code that indicates the PCM has forced the engine to idle as a protective measure. The root cause is almost always another code — such as a throttle body, TPS, or APP sensor fault — that triggered this safety mode.

Faulty throttle position sensor (TPS)25%

Erratic or incorrect voltage readings from the throttle position sensor can cause the PCM to distrust throttle position data and force the engine into a safe idle state until the issue is resolved.

Failed electronic throttle body20%

A malfunctioning throttle body motor or stuck throttle plate can cause the PCM to detect unsafe throttle behavior and force the system into idle mode to prevent unintended acceleration.

Accelerator pedal position sensor failure15%

If the APP sensor sends conflicting or out-of-range signals, the PCM cannot determine the driver's intended throttle input and forces the engine to idle as a safety precaution.