What does B0159 mean on a Chevy?

B0159. Outside air temperature sensor reads out of its valid range. The HVAC module ignores 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 B0159 on a Chevy?

Outside air temperature sensor element drifted out of its valid range Open in the outside air temperature sensor signal circuit Corroded or loose outside air temperature sensor connector Outside air temperature sensor blocked or contaminated by debris Faulty input inside the HVAC control module

How do I fix B0159 on a Chevy?

Confirm the code with a scan tool and watch the outside air temperature reading against a known temperature Inspect and reseat the outside air temperature sensor connector and check for corrosion Test the outside air temperature sensor resistance against the service chart Repair any chafed or open wiring before condemning the sensor Replace the outside air temperature sensor only if it reads out of range at a known temperature, then clear the code and retest

Code

B0159

Outside air temperature sensor reads out of its valid range

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

B0159. Outside air temperature sensor reads out of its valid range. The HVAC module ignores 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 element drifted out of its valid range
Open in the outside air temperature sensor signal circuit
Corroded or loose outside air temperature sensor connector
Outside air temperature sensor blocked or contaminated by debris
Faulty input inside the HVAC control module

Standard procedure

Confirm the code with a scan tool and watch the outside air temperature reading against a known temperature
Inspect and reseat the outside air temperature sensor connector and check for corrosion
Test the outside air temperature sensor resistance against the service chart
Repair any chafed or open wiring before condemning the sensor
Replace the outside air temperature sensor only if it reads out of range at a known temperature, then clear the code and retest

Look up another code

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Sources and review

Review: checked against the recorded source material.

Code B0159 definition | OBDII.pro
live manufacturer definition (obdii.pro)
Supports: GM manufacturer meaning for B0159
Fetched directly. The GM entry is the brand-family meaning used here. This site is independent of engine-codes and autocodes.
B0159 CHEVROLET Ambient Air Temperature Sensor Circuit Range/Performance | 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.
B0159 CHEVROLET Ambient Air Temperature Sensor Circuit Range/Performance | 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).

Last updated 2026-10-10.

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