P0070
Ambient Air Temperature Sensor Circuit A
Generic electrical fault in the ambient air temperature sensor A circuit. Used by the ECU for cold-start corrections, climate logic, and intake-air calculations.
- Check engine light: Yes
- Emissions related: No
- Repair difficulty: easy
Common causes
Ordered by how often each turns out to be the cause.
- Sensor element failedCommon
- Wiring open or connector loosePossible
Parts involved
- Ambient Air Temp Sensor
- Sensor Wiring
P0070 is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.