What it means
The module detects that intake air heater A is not operating or responding within its expected range. It sets the code when the heater circuit or its monitored performance fails the calibrated checks.
At a glance
- Usually lights the check-engine light
How it works
Intake air heater A warms incoming air to support cold starting and operation. The control module checks heater A's circuit and response, and sets this range/performance code when the heater does not behave within its expected operating range.
Common causes
Most likely first.
- Faulty intake air heater
- Blown fuse or faulty relay
- Damaged wiring or connector
- Poor electrical ground
- Control module fault
Symptoms
- Check engine light
- Hard starting when cold
- Longer warm-up
- Reduced cold-weather performance
How to diagnose it
- Review freeze-frame data and ambient or intake-air temperature to see whether the fault occurred during conditions when heater A should operate.
- Inspect heater A's connector, wiring, and ground for corrosion, loose terminals, or heat damage.
- Check the heater A fuse and relay, if fitted, using the vehicle's wiring information.
- Measure heater A's supply, ground, and circuit continuity, comparing results with the manufacturer's specification.
- Use a scan-tool command or specified functional test, if available, to confirm heater A responds correctly before investigating the control module.
Common fixes
- Clean and secure a loose or corroded heater A connector or ground.
- Replace a failed fuse or relay after checking for the reason it failed.
- Repair damaged heater A wiring.
- Replace intake air heater A if it fails the manufacturer's electrical or functional checks.
- Repair a confirmed control-module fault after verifying the heater circuit.
Can I keep driving?
The main concern is hard starting and weaker cold-weather performance, so allow extra time for starting and avoid relying on the vehicle in severe cold until checked. If the engine starts and runs normally, this code alone does not indicate an immediate overheating risk.
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.