What does U1300 mean on a Chevy?

U1300. Class 2 Short to Ground. Applies to Silverado, Sierra, Tahoe, Yukon, Suburban.

What causes U1300 on a Chevy?

Chafed Class 2 serial data wire shorted to chassis ground Pinched harness under seats, console, or door sills Failed module internally shorting the bus to ground Water intrusion in a data line connector Aftermarket device tapped into the Class 2 data line

How do I fix U1300 on a Chevy?

Measure bus voltage; near zero volts confirms a short to ground Disconnect modules one at a time until bus voltage returns Inspect harness routing at known chafe points Remove aftermarket taps from the data line Repair the wiring before replacing any module

Code

U1300

Class 2 Short to Ground

Category: Network Communications
Severity: Check Engine Light
Applies to: Silverado, Sierra, Tahoe, Yukon, Suburban
Related: No single generic twin. See OBD Codes List

What it means

U1300. Class 2 Short to Ground. This Chevy-enhanced code applies to Silverado, Sierra, Tahoe, Yukon, Suburban.

Findings, check these first

Chafed Class 2 serial data wire shorted to chassis ground
Pinched harness under seats, console, or door sills
Failed module internally shorting the bus to ground
Water intrusion in a data line connector
Aftermarket device tapped into the Class 2 data line

Standard procedure

Measure bus voltage; near zero volts confirms a short to ground
Disconnect modules one at a time until bus voltage returns
Inspect harness routing at known chafe points
Remove aftermarket taps from the data line
Repair the wiring before replacing any module

Look up another code

Press / to jump to the box. Chevy-enhanced powertrain, body, chassis and network codes.

Sources and review

Review: no source links are recorded for this entry.

Last updated 2026-09-13.

Report a correction for U1300. Include your vehicle, the issue and a source if you have one.