U043D: Invalid Data Received From Accelerator Pedal Module

What it means

A receiving module detected invalid data from the accelerator pedal module. This code alone does not establish that the pedal position channels disagree or that the engine uses a particular fail-safe strategy.

At a glance

• Usually lights the warning light of the system that lost communication
• Affects emissions; the car can fail an emissions test
• The engine or gearbox may go into limp mode

How it works

The accelerator pedal module reports pedal-related data to other control modules over the vehicle network. U043D means a receiving module has rejected that data as invalid; the code alone does not show whether the pedal channels disagree or what fail-safe response the vehicle uses.

Common causes

Most likely first.

1. Module internal fault or sensor input drift
2. Software version mismatch after replacement
3. Gateway module routing CAN messages incorrectly

Symptoms

• Multiple warning lights may illuminate
• Affected modules may go into limp mode or shut down
• Specific functions inoperative depending on module
• Diagnostic tools may show communication faults

How to diagnose it

1. Scan all modules and save freeze-frame data, pedal-related codes, and communication faults before clearing anything.
2. With the vehicle safely stationary, compare accelerator pedal position reported by the pedal module and engine controller as the pedal is moved gradually.
3. Inspect the pedal module connector and harness for damage, loose terminals, corrosion, or interference from floor mats or other objects.
4. Check for network or gateway faults that could corrupt or misroute the pedal module's messages.
5. If the pedal module or a control module was replaced, verify software compatibility and required configuration before testing the system according to the vehicle's service information.

Common fixes

• Remove any floor mat or obstruction that interferes with pedal movement.
• Repair loose, corroded, or damaged pedal-module wiring and connectors.
• Correct a network or gateway wiring fault identified during diagnosis.
• Update or configure a replacement pedal or control module as specified for the vehicle.
• Replace the pedal module or repair the receiving module only when testing confirms the fault.

Can I keep driving?

Because invalid pedal data can lead to reduced or unpredictable acceleration, avoid driving if response is abnormal, warning lights indicate reduced power, or the engine does not respond consistently. If the vehicle behaves normally and only a warning is present, drive cautiously to a safe place for diagnosis and avoid overtaking or fast traffic.