U0440: Invalid Data Received From Drive Motor Control Module A

What it means

The Drive Motor Control Module is present on the data bus but the values it reports are implausible — out of range, frozen, or failing the checksum or rolling-count check. The receiving modules reject the data. Electric-drive torque control becomes unreliable. Causes include a faulty sensor feeding the module, internal computation errors, a software or calibration mismatch after a repair, or bus interference corrupting the frames.

At a glance

• Usually lights the warning light of the system that lost communication
• The engine or gearbox may go into limp mode

How it works

Drive Motor Control Module A reports electric-drive information to other modules over the vehicle network. U0440 sets when a receiving module rejects data from module A as implausible, which can make torque information unreliable; the code does not alone identify a failed motor sensor or module.

Common causes

Most likely first.

1. Drive motor resolver/sensor drift
2. Drive motor module internal fault
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 and communication codes, noting which module rejected Drive Motor Control Module A data.
2. Review available live data from module A for implausible or changing drive-motor readings and compare it with related modules' data.
3. Inspect the module A connectors, harness, and accessible network wiring for damage, loose connections, corrosion, or signs of recent work.
4. Check for gateway or bus communication faults that could corrupt or misroute module A messages.
5. If the drive motor or a control module was replaced or serviced, verify software and calibration compatibility, then follow the vehicle's high-voltage service procedure to test the system.

Common fixes

• Repair damaged or loose network wiring or connectors serving Drive Motor Control Module A.
• Correct a gateway routing or communication fault confirmed by diagnosis.
• Update or configure replacement drive motor or control modules to the vehicle's required software and calibration.
• Repair a confirmed faulty motor sensor or resolver input to module A.
• Replace Drive Motor Control Module A only after testing rules out wiring, software, and sensor causes.

Can I keep driving?

If the vehicle shows reduced power, an electric-drive warning, or abnormal acceleration, stop safely and follow the vehicle's guidance; do not rely on normal torque response. If it remains drivable without those symptoms, avoid hard acceleration and have the fault diagnosed promptly.