What it means
The drive circuit of EGR throttle A is open. EGR throttles partially close intake to increase exhaust gas recirculation flow at low loads.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
The EGR throttle actuator drive circuit moves throttle A to help increase exhaust-gas recirculation flow under the conditions the system requires. P0487 sets when the control module detects an open in that drive circuit, so the actuator may not move and EGR flow may be insufficient.
Common causes
Most likely first.
- Open or damaged wiring to the EGR throttle actuator
- Faulty EGR throttle actuator
- Loose or corroded connector
- Fault in the control module or its output circuit
Symptoms
- Check engine light on
- Pinging or knocking under load
- Power loss and hesitation
- Possible rough idle
- Failed emissions inspection (NOx)
How to diagnose it
- Review freeze-frame data and live EGR throttle A command or position, if available, to determine when the open-circuit fault occurs.
- Identify EGR throttle A from vehicle service information and inspect its connector and harness for disconnection, corrosion, heat damage, or a broken wire.
- Check the actuator supply, ground, and control wires for continuity and shorts, following the manufacturer’s wiring information.
- Test the EGR throttle A actuator circuit and actuator for an open condition using the manufacturer’s procedure.
- If the actuator and harness pass, verify the control module output circuit before considering a module fault.
Common fixes
- Reconnect and secure a loose EGR throttle A connector.
- Clean corroded terminals or replace a damaged connector.
- Repair an open or broken wire in the actuator drive circuit.
- Replace the EGR throttle A actuator if it fails the specified electrical test.
Can I keep driving?
You may be able to drive if the engine runs normally, but avoid heavy loads if it hesitates or knocks. The EGR fault can affect drivability and emissions, so address it before an emissions inspection.
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.