Loss of class 2 communication with powertrain control module
What it means
U1016. Loss of class 2 communication with powertrain control module. PCM stopped talking on bus. This Chevy-enhanced code applies to Silverado, Sierra, Tahoe, Suburban 1999 to 2006. Corvette, Camaro of same era..
Findings, check these first
- Faulty PCM power or ground
- Open class 2 wire to PCM
- Corroded PCM connectors
- Faulty PCM
- Shorted data bus
Standard procedure
- Check PCM fuses and grounds
- Inspect PCM connectors
- Test class 2 wire continuity
- Try communication with enhanced scan tool
- Replace PCM only after circuit tests pass
Look up another code
Press / to jump to the box. Chevy-enhanced powertrain, body, chassis and network codes.
Sources and review
Review: checked against the recorded source material.
- U1016 GMC: Code Meaning, Causes, Symptoms, & Tech Notes
archived reference page (engine-codes.com via Wayback Machine)
Supports: code identity and GM (GMC) application
Fetched directly. The GMC page names lost communications with powertrain/engine control module over the class 2 bus, matching the catalog PCM bus loss.
- U1016 CHEVROLET SCP Invalid or Missing Data for Primary Id
archived reference page (autocodes.com via Wayback Machine)
Supports: code identity and Chevrolet application, with SCP wording
Fetched directly. The Chevrolet page uses SCP invalid or missing data wording for the same bus communication code.
Last updated 2026-09-25.
Report a correction for U1016. Include your vehicle, the issue and a source if you have one.