U0308 — Software Incompatibility with Throttle Actuator Control Module

OBD2 code U0308 flags a problem with the throttle and intake air metering (software incompatibility with throttle actuator control module). Short, gentle driving to a shop is usually possible. Common culprits: failed electronic throttle motor, intake air leaks after the MAF sensor, contaminated or failed MAF/MAP sensor.

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 U0308 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 U0308 does not return.

Approximate repair cost

Repair cost depends on which component actually failed. Typical scenarios for U0308 (parts and labor, USD, independent shop rates): Clean the throttle body: $80–$200; Replace the throttle body assembly: $250–$700; Replace the MAF or MAP sensor: $150–$400. Overall, fixing U0308 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 is the most common cause of U0308?

The most common causes are: failed electronic throttle motor, intake air leaks after the MAF sensor, contaminated or failed MAF/MAP sensor.

What are the symptoms of U0308?

Drivers most often notice: limp-home mode with reduced power, unstable or high idle, poor throttle response, Check Engine Light on.

How do I diagnose U0308 myself?

Start with a scan: confirm U0308, 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.

Will U0308 clear itself?

Sometimes U0308 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 U0308?

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 U0308 mean?

U0308 is logged by the onboard diagnostics when the throttle and intake air metering does not behave as expected. The official definition is “Software Incompatibility with Throttle Actuator Control Module”. This is a vehicle network category code.

The module monitors this system continuously while driving. When readings fall outside the expected range for a defined number of drive cycles, it stores U0308 and switches on the warning light. Freeze frame data saved with the code shows the exact conditions — rpm, load, temperature, speed — at the moment the fault was detected, which is the best starting point for diagnosis.

What causes U0308?

failed electronic throttle motor
intake air leaks after the MAF sensor
contaminated or failed MAF/MAP sensor
wiring or connector faults in the throttle circuit

Common symptoms of U0308

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

How to diagnose U0308

Connect an OBD2 scanner, confirm U0308 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 U0308 does not return.

How to fix U0308

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

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

How much does it cost to fix U0308?

Repair cost depends on which component actually failed. Typical scenarios for U0308 (parts and labor, USD, independent shop rates):

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

Overall, fixing U0308 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.