Electric rear defrost circuit range fault
What it means
B0284. Electric rear defrost circuit range fault. The defrost grid current reads outside its expected range and the body warning light comes on. This Chevy-enhanced code applies to Chevrolet, GMC, Buick, Cadillac, Pontiac, Oldsmobile and Saturn models that use this code.
Findings, check these first
- Rear defrost grid current outside its expected range
- Partially broken grid element in the rear glass
- Blown or corroded rear defrost fuse
- Failed rear defrost relay
- Faulty output inside the body control module
Standard procedure
- Confirm the code with a scan tool and command the rear defrost on
- Measure the rear defrost grid current against spec
- Check the rear defrost fuse and relay
- Test the rear defrost grid and its tab for continuity
- Repair the grid or replace the rear defrost relay only after the circuit tests pass, then clear the code and retest
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.
- Code B0284 definition | OBDII.pro
live manufacturer definition (obdii.pro)
Supports: GM manufacturer meaning for B0284
Fetched directly. The GM entry is the brand-family meaning used here. This site is independent of engine-codes and autocodes.
- B0284 CHEVROLET Electric Rear Defrost Circuit Range/Performance | Engine-Codes.com
archived reference page (engine-codes.com via Wayback Machine)
Supports: Chevrolet meaning and possible causes for B0284
Fetched directly. Model and year fitment remain curator claims.
- B0284 CHEVROLET Electric Rear Defrost Circuit Range/Performance | AutoCodes.com
archived reference page (autocodes.com via Wayback Machine)
Supports: corroboration of Chevrolet meaning and causes for B0284
Same Chevrolet text as the engine-codes page (both sites share one publisher).
Last updated 2026-10-10.
Report a correction for B0284. Include your vehicle, the issue and a source if you have one.