Invalid Data Received From Suspension Control Module A

Where it lives

For U0421, start at the module the description names.

Check these first

• An interrupted ground to the Suspension Control Module A
• An open or short in the Suspension Control Module A wiring
• Corroded or damaged pins at the Suspension Control Module A connector

What to do next

1. Read the stored codes on a scan tool
2. Check the Suspension Control Module A connector for water, corrosion, or loose pins
3. Replace the Suspension Control Module A if the circuit and grounds test good
4. Clear the code and retest

Look up another code