OBD-II Generic Error Code U1016: How to Fix It

Medium 1-2 hours Medium Severity Verified July 2026
Error Code
U1016
Brand
OBD-II Generic
Product Type
automotive
Severity
Medium
DIY Difficulty
Medium
Estimated Fix Time
1-2 hours
Error code U1016 means the PCM (Powertrain Control Module) is not communicating properly with other modules. This can cause drivability issues and prevent the vehicle from passing emissions tests.
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Tools You'll Need

How to Fix Error Code U1016

  1. Check Battery Voltage and Connections

    Disconnect negative terminal before cleaning terminals.
  2. Inspect OBD-II Diagnostic Link Connector (DLC) Wiring

  3. Test CAN Bus Wiring

    Use proper safety gear when working with electrical systems.
  4. Check for Blown Fuses

    Never use a higher amp fuse than specified.
  5. Inspect PCM Ground and Power Supply

    Disconnect battery before handling PCM connector.
  6. Perform PCM Reset or Reprogram

Parts You May Need

Battery terminals/connectors
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CAN bus wiring harness
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Battery terminals/connectors
Check Price on Amazon
CAN bus wiring harness
Check Price on Amazon
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When to Call a Professional

If you've checked wiring, fuses, and connections but the code persists, a professional may need to diagnose deeper electrical issues or replace the PCM.

Frequently Asked Questions

What does error code U1016 mean?
It indicates a loss of communication with the Powertrain Control Module (PCM) on GM vehicles.
Can a bad battery cause code U1016?
Yes, low battery voltage can disrupt communication between modules.
Is it safe to drive with code U1016?
It may affect drivability and emissions. Get it diagnosed as soon as possible.
Will clearing the code fix U1016?
Clearing the code may temporarily turn off the check engine light, but the underlying issue will likely return.
How much does it cost to fix U1016?
Depends on the cause. Simple fixes like a loose ground cable are cheap; PCM replacement can cost $500-$1000.