U0408 — Invalid Data Received From Throttle Actuator Control Module

vehicle network

Is it safe to drive?

Drive with caution Drive with caution. Many throttle faults put the car into limp mode with limited power — enough to reach a shop, not for highway trips. If the engine stalls or the pedal stops responding, do not drive.

How to diagnose with an OBD scanner

Read the code and freeze frame Connect an OBD2 scanner, confirm U0408 is stored, and save the freeze frame data — it shows engine conditions when the fault was detected.
Check for companion codes and TSBs Related codes often reveal the real root cause. Also check manufacturer technical service bulletins (TSB) for your make and model — many U0xxx issues have factory fixes or software updates. Search by VIN on the manufacturer site or nhtsa.gov.
Inspect wiring and connectors Visually inspect the wiring harness and connectors related to the throttle and intake air metering for damage, corrosion, chafing or poor contact.
Subsystem check Inspect and clean the throttle body; check that the plate moves freely.
Subsystem check Watch throttle position and MAF/MAP readings in live data while pressing the pedal — values should change smoothly.
Verify the repair Clear the code, complete a full drive cycle including the conditions from the freeze frame, and confirm U0408 does not return.

Approximate repair cost

Repair cost depends on which component actually failed. Typical scenarios for U0408 (parts and labor, USD, independent shop rates): Replace the MAF or MAP sensor: $150–$400; Clean the throttle body: $80–$200; Replace the throttle body assembly: $250–$700. Overall, fixing U0408 usually costs between $80 and $700. An accurate diagnosis before buying parts saves money — the most expensive scenario is rarely the first one to check.

Common questions

What are the symptoms of U0408?

Drivers most often notice: limp-home mode with reduced power, stalling when coming to a stop, Check Engine Light on, poor throttle response.

How do I diagnose U0408 myself?

Start with a scan: confirm U0408, save the freeze frame and note any companion codes. Then inspect the wiring and connectors related to the throttle and intake air metering, and verify the suspect component against live data before buying parts.

What is the most common cause of U0408?

The most common causes are: dirty throttle body or stuck throttle plate, intake air leaks after the MAF sensor, faulty throttle position sensor or pedal sensor.

Will U0408 clear itself?

Sometimes U0408 clears after a few drive cycles if the fault was intermittent — for example a loose connector or a tank of bad fuel. The underlying cause usually remains, so the code tends to return. Clear it once; if it comes back, diagnose rather than erase it repeatedly.

Is it safe to drive with U0408?

Drive with caution. Many throttle faults put the car into limp mode with limited power — enough to reach a shop, not for highway trips. If the engine stalls or the pedal stops responding, do not drive.

What does U0408 mean?

Seeing U0408 on your scanner? The control unit has caught the throttle and intake air metering operating outside its calibrated window. The formal description is “Invalid Data Received From Throttle Actuator Control Module”, and the code is grouped under vehicle network faults.

To set U0408, the control module compares live readings of the throttle and intake air metering against calibrated limits, usually over several drive cycles. Alongside the code it stores a freeze frame — a snapshot of rpm, load, coolant temperature and vehicle speed at the moment of failure. Reading that snapshot first saves diagnostic time.

What causes U0408?

dirty throttle body or stuck throttle plate
wiring or connector faults in the throttle circuit
failed electronic throttle motor
contaminated or failed MAF/MAP sensor
faulty throttle position sensor or pedal sensor
intake air leaks after the MAF sensor

Common symptoms of U0408

limp-home mode with reduced power
stalling when coming to a stop
Check Engine Light on
poor throttle response
unstable or high idle

How to diagnose U0408

Connect an OBD2 scanner, confirm U0408 is stored, and save the freeze frame data — it shows engine conditions when the fault was detected.
Related codes often reveal the real root cause. Also check manufacturer technical service bulletins (TSB) for your make and model — many U0xxx issues have factory fixes or software updates. Search by VIN on the manufacturer site or nhtsa.gov.
Visually inspect the wiring harness and connectors related to the throttle and intake air metering for damage, corrosion, chafing or poor contact.
Inspect and clean the throttle body; check that the plate moves freely.
Watch throttle position and MAF/MAP readings in live data while pressing the pedal — values should change smoothly.
Clear the code, complete a full drive cycle including the conditions from the freeze frame, and confirm U0408 does not return.

How to fix U0408

Start with the cheapest and most common causes before replacing expensive parts:

Replace the MAF or MAP sensor — $150–$400
Clean the throttle body — $80–$200
Replace the throttle body assembly — $250–$700

How much does it cost to fix U0408?

Repair cost depends on which component actually failed. Typical scenarios for U0408 (parts and labor, USD, independent shop rates):

Replace the MAF or MAP sensor: $150–$400
Clean the throttle body: $80–$200
Replace the throttle body assembly: $250–$700

Overall, fixing U0408 usually costs between $80 and $700. An accurate diagnosis before buying parts saves money — the most expensive scenario is rarely the first one to check.