What it means
The particulate matter sensor heater control circuit is reading below its expected range.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
The PM sensor heater control circuit supplies or switches power to warm the exhaust sensor. This code sets when the module detects a circuit reading below its expected range, which can result from a short to ground or excessive resistance in a connection.
Common causes
Most likely first.
- Control line shorted to ground
- Connector pins corroded - high contact resistance
- Harness chafing through insulation
Symptoms
- Check-engine light on
- Particulate matter sensor or aftertreatment warning
- Emissions inspection failure
How to diagnose it
- Save freeze-frame data and check for other heater or aftertreatment codes that could indicate a shared circuit problem.
- Inspect the heater connector for corrosion, moisture, loose terminals, or heat damage.
- Check the heater control wire along the exhaust for rubbed-through insulation or contact with ground.
- Compare the commanded heater state with live circuit data, then test the control wire for a short to ground using the manufacturer's wiring information.
- If the wiring checks out, test the PM sensor heater and control circuit according to the manufacturer's procedure.
Common fixes
- Repair insulation rubbed through against ground.
- Clean and secure corroded or loose heater connector terminals.
- Repair a damaged heater control wire or connector.
- Replace the PM sensor if testing confirms an internal heater fault.
Can I keep driving?
If the vehicle drives normally, cautious short-distance driving is generally possible, but address the fault promptly. The heater may not warm the PM sensor correctly, compromising emissions monitoring.
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.