P0487
EGR Throttle Control Circuit A /Open
EGR (emissions)
Generic OBD-II
Medium
What it means
P0487 means the engine computer has detected an open in the control circuit for the EGR throttle valve. This throttle works with the EGR system (mostly on diesels) to help draw exhaust into the intake, so an open circuit can cause rough idle, hesitation, and higher emissions, though the car will usually still drive.
Medium
Can I keep driving? Usually yes, but idle may be rough and the engine could hesitate; have it repaired soon to avoid stalling and emissions problems.
Common symptoms
What you'll notice
- Check-engine light on
- Rough idle or hesitation
- Occasional stalling, mainly on diesels
- Reduced fuel economy and higher emissions
Common causes
Most likely first
- Open in the EGR throttle control circuit wiringLikely
- Faulty EGR throttle valve actuator or motorCommon
- Corroded or disconnected connector at the actuatorCommon
- Failed EGR control solenoid/driverLess often
- ECM output fault (least common)Less often
How to diagnose & fix
Work through it in order
- Read freeze-frame data and confirm whether the open is present now or intermittent.
- Inspect the EGR throttle actuator connector and wiring for an open circuit, corrosion, or a loose pin.
- Measure the actuator's circuit for continuity and check its resistance against spec.
- Replace the EGR throttle valve/actuator if its control circuit is open internally; repair harness faults found.
- Clear the code and confirm the circuit no longer reads open.
FAQ
Quick answers
Is it safe to drive with P0487?+
Short trips are usually fine, but a rough idle or hesitation can worsen. Have the EGR throttle circuit repaired promptly, particularly on a diesel where it can cause stalling.
Can I just clear P0487?+
It clears, but an open control circuit will set it again. Repair the wiring or actuator first.
Related codes
Often seen with P0487
Read & clear P0487 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.
✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX