U040A

Invalid Data Received From Air Conditioning Control Module

Severity

⚠️ Medium

Can you drive?

Yes, but get it checked soon

Approx. repair cost

$56–278 (est.)

Symptoms

Incorrect operation of the air conditioning system
No cold air from vents
Spontaneous turning on/off of the air conditioner
Error message on the dashboard
Some climate control functions do not work

Causes

Air conditioning control module malfunction
Problems with wiring to the air conditioning module
Corrosion or poor contact in connectors
Problems with power supply to the air conditioner module
Interference on the CAN bus

How to Fix

Check the power and ground of the air conditioner module
Inspect connectors and wiring for damage
Scan the air conditioner module for errors
Check the quality of communication via the CAN bus
If necessary, replace the air conditioning control module

Related codes

U040B U0401 U0402