What does B0252 mean on a Chevy?

B0252. Blend defog and floor door circuit is open. That air flow door gets no command and the body warning light comes on. Applies to Chevrolet, GMC, Buick, Cadillac, Pontiac, Oldsmobile and Saturn models that use this code.

What causes B0252 on a Chevy?

Open in the blend defog and floor door actuator circuit Unseated or corroded blend defog and floor door actuator connector Broken blend defog and floor door actuator harness behind the dash Binding or stripped blend defog and floor door actuator gears Faulty output inside the HVAC control module

How do I fix B0252 on a Chevy?

Confirm the code with a scan tool and command the blend defog and floor door Wiggle-test the blend defog and floor door harness while watching the command Inspect and reseat the blend defog and floor door actuator connector Test the blend defog and floor door circuit for an open Replace the blend defog and floor door actuator only after the circuit tests pass, then clear the code and retest

Code

B0252

Blend defog and floor door circuit is open

Category: Body
Severity: Body Warning Light
Applies to: Chevrolet, GMC, Buick, Cadillac, Pontiac, Oldsmobile and Saturn models that use this code
Related: No single generic twin. See OBD Codes List

What it means

B0252. Blend defog and floor door circuit is open. That air flow door gets no command 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

Open in the blend defog and floor door actuator circuit
Unseated or corroded blend defog and floor door actuator connector
Broken blend defog and floor door actuator harness behind the dash
Binding or stripped blend defog and floor door actuator gears
Faulty output inside the HVAC control module

Standard procedure

Confirm the code with a scan tool and command the blend defog and floor door
Wiggle-test the blend defog and floor door harness while watching the command
Inspect and reseat the blend defog and floor door actuator connector
Test the blend defog and floor door circuit for an open
Replace the blend defog and floor door actuator 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: qualified. Read the source limits below.

Code B0252 definition | OBDII.pro
live manufacturer definition (obdii.pro)
Supports: GM manufacturer meaning for B0252
Fetched directly. The GM entry is the brand-family meaning used here. This site is independent of engine-codes and autocodes.
B0252 CHEVROLET Mode Door Inoperative | Engine-Codes.com
archived reference page (engine-codes.com via Wayback Machine)
Supports: Chevrolet meaning and possible causes for B0252
Fetched directly. Model and year fitment remain curator claims.
B0252 CHEVROLET Mode Door Inoperative | AutoCodes.com
archived reference page (autocodes.com via Wayback Machine)
Supports: corroboration of Chevrolet meaning and causes for B0252
Same Chevrolet text as the engine-codes page (both sites share one publisher).

Review note: obdii.pro GM names the blend defog and floor door circuit open; the archived Chevrolet page names the mode door inoperative fault. The circuits differ, so the record uses the GM wording and flags the conflict

Last updated 2026-10-10.

Report a correction for B0252. Include your vehicle, the issue and a source if you have one.