U0596: Invalid Data Received From AC To AC Converter Control Module

What it means

A receiving control module has detected invalid data from the AC To AC Converter Control Module. The code does not specify which data is invalid or why.

How it works

The AC to AC Converter Control Module manages an onboard converter that changes one form of alternating-current power to another in vehicles equipped with that system. U0596 sets when a receiving module considers data from this converter controller invalid; the code does not identify the failed value or cause.

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 and converter, charging, or communication codes to identify the reporting module and related symptoms.
2. Check low-voltage battery and charging condition, since the converter controller’s electronics depend on stable vehicle supply.
3. Inspect accessible AC to AC converter controller connectors and low-voltage wiring for damage, moisture, loose pins, or prior repair.
4. Use a scan tool capable of reading converter data to compare controller status and reported operating values with related modules.
5. Check gateway and network faults and test the controller’s low-voltage power, ground, and data circuits to the manufacturer’s specification.
6. If converter or control modules were replaced or programmed, verify the correct software and vehicle configuration before replacing components.

Common fixes

• Repair damaged or poorly seated low-voltage connectors or wiring at the converter controller.
• Correct a weak low-voltage battery or charging fault affecting communications.
• Update or configure a replacement controller if the software or setup is incompatible.
• Repair a gateway or network communication fault identified by testing.
• Replace the AC to AC Converter Control Module only if circuit and software checks confirm an internal failure.

Can I keep driving?

If the vehicle displays a converter, charging, or electrical-system warning, follow its instructions and avoid relying on the affected charging or power-conversion function. Stop driving if power is limited or the vehicle behaves unpredictably, and do not handle high-voltage equipment.