A/C Evaporator Air Temperature Circuit Range/Performance
Findings, check these first
- Drifting evaporator sensor
- Iced evaporator skewing readings
- Low refrigerant charge
- Intermittent connector
- Failing sensor
Standard procedure
- Check for evaporator icing and low charge
- Compare sensor to vent temperatures
- Wiggle-test the connector
- Verify charge level
- Replace the sensor if readings stay off
Code lookup
Type a code above, or start from a symptom or a common code.
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Sources and review
Review: checked against the recorded source material.
- OBDII.pro: P1438 Ford definition
live reference page (obdii.pro)
Supports: Ford-family meaning for P1438: A/C Evaporator Air Temperature Circuit Range/Performance
Fetched directly. obdii.pro is a publisher independent of the engine-codes family.
- P1438 FORD Code: Meaning, Causes, and Symptoms | OBD2 Codes
live reference page (obd2-codes.co)
Supports: Ford meaning for P1438: A/C Evaporator Air Temperature Circuit Range/Performance
Fetched directly. obd2-codes.co phrasing matches the engine-codes family, so it counts as one publisher.
Last updated 2026-09-06.
Report a correction for P1438. Include your vehicle, the issue and a source if you have one.