What it means
The control module detected a high electrical signal in the diesel intake air flow control circuit.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
The diesel intake air flow control actuator circuit carries electrical signals between the control module and the airflow valve actuator. This code sets when the module detects a signal above the expected range, which can result from a short to battery voltage or a supply wire contacting a powered source.
Common causes
Most likely first.
- Short to B+
- Connector pins corroded - high contact resistance
- Supply wire pinched against B+ source
Symptoms
- Check-engine light on
- Reduced engine power or sluggish acceleration
- Rough idle or stalling
- Increased fuel consumption
How to diagnose it
- Save freeze-frame data and check available actuator command and position data to determine whether the high signal is constant or occurs under particular conditions.
- Inspect the intake air flow control connector and harness for damaged insulation, pinched wires, corrosion, or a signal wire touching a power source.
- Check connector terminals for corrosion or poor contact, and look for repairs or splices that may have joined the circuit to a supply wire.
- Using the manufacturer’s wiring diagram, test the signal circuit for a short to battery voltage and verify its connections.
- If the wiring checks out, test the actuator and control-module circuit as directed by the manufacturer.
Common fixes
- Repair a signal wire shorted to a power source.
- Replace damaged or pinched harness sections and secure them away from powered wiring.
- Clean or replace corroded or damaged connector terminals.
- Replace the actuator only if circuit testing confirms it is faulty.
Can I keep driving?
If the engine runs steadily, limit driving and avoid heavy loads because incorrect airflow control can cause sluggish response or stalling. Stop if it stalls repeatedly or loses enough power to make traffic unsafe.
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.