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.

Real-world scan data

Seen in

2,266

scans in the past year

Found in

0.4%

of scans

0.6%

of scans that found faults

Appears alongside · share of P0487 scans

C0487in 36.6% of scans

P0406in 35.6% of scans

P0401in 25.5% of scans

Figures reflect only diagnostic scans recorded through our own apps and tools. Cars are typically scanned because a symptom or warning light prompted it, so these counts describe our scan records — not the incidence of faults in any model, and not the quality, reliability, or safety of any vehicle. No comparison between manufacturers or models is implied. All trademarks belong to their respective owners; no affiliation or endorsement is implied.

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.

Read & clear P0487 yourself

Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.

▶ Get it on Google Play

✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX