Windscreen temperature sensor circuit fault
What it means
B018A. Windscreen temperature sensor circuit fault. The HVAC module cannot read the glass temperature and sets a body warning light. This Chevy-enhanced code applies to Chevrolet, GMC, Buick, Cadillac, Pontiac, Oldsmobile and Saturn models that use this code.
Findings, check these first
- Failed windscreen temperature sensor with an out of range element
- Open or short in the sensor signal circuit
- Corroded or loose sensor connector
- Sensor contaminated or blocked by debris
- Faulty input inside the HVAC control module
Standard procedure
- Confirm the code with a scan tool and compare the reading to a known temperature
- Inspect and reseat the sensor connector and check for corrosion
- Test the sensor and its signal circuit against the service chart
- Repair any chafed or open wiring before condemning the sensor
- Replace the sensor only if its reading does not match actual temperature
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.
- B018A CHEVROLET Windscreen Temperature Sensor Circuit | 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.
- B018A CHEVROLET Windscreen Temperature Sensor Circuit | 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: No live obdii.pro GM entry and both archive pages are one publisher, so the windscreen temperature sensor meaning rests on one source
Last updated 2026-09-26.
Report a correction for B018A. Include your vehicle, the issue and a source if you have one.