What does B0161 mean on a Chevy?

B0161. Outside air temperature sensor circuit voltage is high. The HVAC module cannot trust the ambient reading and sets a body warning. Applies to Chevrolet, GMC, Buick, Cadillac, Pontiac, Oldsmobile and Saturn models that use this code.

What causes B0161 on a Chevy?

Outside air temperature sensor signal circuit open Outside air temperature sensor element failed open Corroded or loose outside air temperature sensor connector Outside air temperature sensor harness broken in the front fascia Faulty input inside the HVAC control module

How do I fix B0161 on a Chevy?

Confirm the code with a scan tool and read the outside air temperature sensor voltage Inspect and reseat the outside air temperature sensor connector Test the outside air temperature sensor signal circuit for an open from the sensor to the HVAC control module Repair any broken wiring in the front fascia before condemning the sensor Replace the outside air temperature sensor only if the signal stays high with the circuit intact, then clear the code and retest

Code

B0161

Outside air temperature sensor circuit voltage is high

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

B0161. Outside air temperature sensor circuit voltage is high. The HVAC module cannot trust the ambient reading and sets a body warning. This Chevy-enhanced code applies to Chevrolet, GMC, Buick, Cadillac, Pontiac, Oldsmobile and Saturn models that use this code.

Findings, check these first

Outside air temperature sensor signal circuit open
Outside air temperature sensor element failed open
Corroded or loose outside air temperature sensor connector
Outside air temperature sensor harness broken in the front fascia
Faulty input inside the HVAC control module

Standard procedure

Confirm the code with a scan tool and read the outside air temperature sensor voltage
Inspect and reseat the outside air temperature sensor connector
Test the outside air temperature sensor signal circuit for an open from the sensor to the HVAC control module
Repair any broken wiring in the front fascia before condemning the sensor
Replace the outside air temperature sensor only if the signal stays high with the circuit intact, 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 B0161 definition | OBDII.pro
live manufacturer definition (obdii.pro)
Supports: GM manufacturer meaning for B0161
Fetched directly. The GM entry is the brand-family meaning used here. This site is independent of engine-codes and autocodes.
B0161 CHEVROLET Ambient Air Temperature Sensor Low | Engine-Codes.com
archived reference page (engine-codes.com via Wayback Machine)
Supports: Chevrolet meaning and possible causes
Fetched directly. Model and year fitment remain curator claims.
B0161 CHEVROLET Ambient Air Temperature Sensor Low | AutoCodes.com
archived reference page (autocodes.com via Wayback Machine)
Supports: corroboration of Chevrolet meaning and causes
Same Chevrolet text as the engine-codes page (both sites share one publisher).

Review note: obdii.pro GM says the outside air temperature circuit is high; the archive says the sensor reads low. The sources disagree on direction

Last updated 2026-10-10.

Report a correction for B0161. Include your vehicle, the issue and a source if you have one.