Faulty accelerator pedal position sensor assembly, including worn tracks or internal potentiometer failure; Damaged or corroded wiring between the accelerator pedal module and the engine control module, such as chafed harness or water intrusion at connectors; Poor electrical ground or loose battery terminal causing voltage instability that corrupts sensor data; Software or calibration issue in the engine control module or pedal module requiring reflash or relearn; Aftermarket electronic throttle controllers or pedal tuners interfering with the original signal; CAN bus communication fault, such as a shorted or open data line, that corrupts messages from the pedal module; Failed engine control module or pedal interface circuit, though this is the least common cause

DTC codes / U04xx · Invalid data received from a module / U043D

U043DInvalid Data Received From Accelerator Pedal Module

Q: What does code U043D mean?

Invalid Data Received From Accelerator Pedal Module. U043D is a communication fault where one control module receives data from the accelerator pedal module that it considers invalid, meaning the message arrives but the values or checksum fail plausibility checks. The computer has detected that the pedal position signal is corrupted, out of range, or inconsistent with other throttle inputs, so it cannot trust the driver's demand for engine torque.

U043D is a communication fault where one control module receives data from the accelerator pedal module that it considers invalid, meaning the message arrives but the values or checksum fail plausibility checks. The computer has detected that the pedal position signal is corrupted, out of range, or inconsistent with other throttle inputs, so it cannot trust the driver's demand for engine torque.

SystemNetwork

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyIntermediate

AreaInvalid data received from a module

Symptoms you may notice

Illuminated check engine light or electronic throttle control warning light, often with reduced engine power mode
Engine may idle erratically, hesitate, or fail to rev beyond a limited speed
Accelerator pedal feels unresponsive or requires unusual pressure to accelerate
Intermittent loss of power or sudden drop to limp-home mode while driving
Often no symptoms besides the warning light, especially if the fault is stored but not currently active
Transmission may shift harshly or refuse to downshift because torque demand is unknown

Common causes, most likely first

Faulty accelerator pedal position sensor assembly, including worn tracks or internal potentiometer failure
Damaged or corroded wiring between the accelerator pedal module and the engine control module, such as chafed harness or water intrusion at connectors
Poor electrical ground or loose battery terminal causing voltage instability that corrupts sensor data
Software or calibration issue in the engine control module or pedal module requiring reflash or relearn
Aftermarket electronic throttle controllers or pedal tuners interfering with the original signal
CAN bus communication fault, such as a shorted or open data line, that corrupts messages from the pedal module
Failed engine control module or pedal interface circuit, though this is the least common cause

How to diagnose and fix it

Scan all modules for related codes and record freeze-frame data to see when the invalid pedal data occurred
Inspect the accelerator pedal connector and harness for corrosion, loose pins, or chafed wires, and clean or repair as needed
Check battery voltage and ground connections, including the engine control module ground, to rule out supply issues
Use a scan tool to view live accelerator pedal position sensor voltages and compare them to the specified range through the full pedal travel
Perform a throttle pedal relearn or calibration procedure if the manufacturer requires it after any service
If live data shows erratic or out-of-range pedal signals, replace the accelerator pedal assembly with a quality part and relearn it
If the fault persists after pedal replacement, diagnose the CAN bus and engine control module circuits with an oscilloscope before condemning the module

Why the pedal module sends invalid data

Many vehicles use two or more redundant pedal position sensors with opposite voltage sweeps, so a single worn track can set U043D even when the pedal still feels normal to the driver.
A weak or failing battery is a frequent hidden cause because voltage dips during cranking can corrupt the pedal module's startup self-test and store this code without any hard fault.
Aftermarket floor mats or pedal covers that restrict full pedal travel can cause the module to report an implausible range and set U043D intermittently.
This code does not always mean the pedal assembly is bad; a poor connection at the engine control module or a failing ground can produce the same invalid data message.
Clearing the code without checking live pedal data often leads to a comeback, because the fault may be stored only under specific temperature or voltage conditions.

Can I keep driving with U043D?

You can usually drive the vehicle to a repair shop if the engine runs normally and the warning light is steady, but avoid heavy acceleration or highway merging because the vehicle may enter reduced power mode without warning. If the engine idles poorly, stalls, or repeatedly drops to limp-home mode, stop driving and arrange a tow to prevent a dangerous loss of power.

Tools that help

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Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.