What it means
The control module detects an intermittent or erratic signal in the hybrid battery pack air temperature sensor A circuit.
At a glance
- Usually lights the check-engine light
- The engine or gearbox may go into limp mode
How it works
Battery-pack air temperature sensor A reports the temperature of air around the hybrid or EV battery, and the control module uses the signal to manage battery operation. This code sets when the signal from sensor A becomes intermittent or erratic instead of remaining stable and changing plausibly with temperature.
Common causes
Most likely first.
- Intermittent wiring or connector fault
- Failed sensor
- Poor ground or connection
Symptoms
- Hybrid system warning light
How to diagnose it
- Review freeze-frame data and graph sensor A’s live reading to look for sudden jumps or dropouts, comparing with sensor B and ambient conditions where possible.
- Inspect sensor A’s connector for loose fit, corrosion, moisture, or damaged terminals, and check accessible wiring for chafing or strain.
- Following manufacturer safety instructions, gently move the accessible sensor A harness while monitoring live data to see whether movement reproduces the dropout.
- Check sensor A’s circuit connections and ground for intermittent contact, using the wiring diagram and manufacturer’s test procedure.
- Test sensor A and its wiring for stable operation against manufacturer’s specifications before replacing parts.
Common fixes
- Reseat and secure sensor A’s connector.
- Repair loose, corroded, or damaged terminals and wiring in sensor A’s circuit.
- Repair a poor ground or connection confirmed by testing.
- Replace sensor A if its signal remains erratic with sound wiring and connections.
Can I keep driving?
An intermittent reading can cause the hybrid system to restrict power or battery cooling without warning. Keep trips short and gentle until repaired, and stop if a warning coincides with overheating or sudden power loss.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.