P0487 – Exhaust Gas Recirculation Throttle Position Control Circuit

P0487 is an OBD-II trouble code that points to a problem with your engine’s EGR (Exhaust Gas Recirculation) system, specifically the throttle or control circuit. When this code sets, your ECU has detected that the EGR throttle isn’t responding the way it should. You might notice poor performance, more smoke on diesels, or just a check engine light with no obvious drivability issues. Left alone, P0487 can lead to carbon buildup and higher emissions. The good news: with a methodical approach, you can diagnose and fix it without guessing.

What Does P0487 Mean?

P0487 stands for “Exhaust Gas Recirculation (EGR) Throttle Position Control Circuit A.” In plain language, your ECU commanded the EGR throttle or control valve to move, but the feedback signal (position or voltage) didn’t match what the ECU expected.

This code is especially common on modern diesel engines that use an EGR throttle plate to help pull exhaust gases into the intake. It can be an electrical issue (wiring, connector, sensor) or a mechanical issue (sticking valve, carbon buildup). The ECU detects the mismatch and stores P0487, often along with other EGR-related codes.

Quick Reference

• Code: P0487 – EGR Throttle Position Control Circuit “A”
• System: Exhaust Gas Recirculation (EGR)
• Severity: Low to moderate, but should not be ignored
• Common Causes: Sticking EGR throttle, carbon buildup, wiring faults, bad EGR valve
• Typical Symptoms: Check engine light, rough idle, reduced power, increased smoke (diesels)

Real-World Example / Field Notes

In the shop, I see P0487 most often on diesel pickups and small European diesels. A common scenario: the owner complains of sluggish acceleration and more black smoke when towing. Scan shows P0487 plus maybe another EGR code. Pulling the intake hose reveals a heavy layer of carbon around the EGR throttle plate. Once cleaned and the connector corrosion removed, the code stays gone. On other vehicles, the wiring right at the EGR throttle plug is brittle and broken inside the insulation, causing intermittent P0487 that only shows up when the engine bay gets hot.

Symptoms of P0487

• Check engine light on: The MIL/SES lamp is usually the first and sometimes only sign.
• Rough idle: Unstable or “hunting” idle, especially when the engine is warm.
• Reduced power: Noticeable lack of acceleration, particularly at low RPM or under load.
• Increased smoke (diesels): Excess black or gray exhaust smoke during acceleration.
• Poor fuel economy: More frequent fuel stops due to inefficient combustion.
• Hesitation or surging: Engine may stumble or surge when you tip into the throttle.
• Regeneration issues (DPF vehicles): On diesel vehicles with DPF, regens may be less effective or more frequent.

Common Causes of P0487

Most Common Causes

• Carbon buildup in the EGR throttle: Soot and oil residue can cause the EGR throttle plate to stick, preventing it from reaching the commanded position.
• Faulty EGR throttle/valve assembly: The internal motor or position sensor can fail, sending incorrect feedback to the ECU.
• Damaged wiring or loose connector: Broken wires, poor pin fit, or corrosion at the EGR throttle connector can interrupt the control or feedback signal.
• Incorrect EGR flow due to sticking main EGR valve: If the main EGR valve is stuck open or closed, the ECU may see unexpected readings and set P0487.
• Vacuum-related issues (on vacuum-operated systems): Leaking vacuum lines or a weak vacuum solenoid can prevent proper EGR throttle movement.

Less Common Causes

• ECU software issues: In rare cases, outdated ECU calibration or software glitches can trigger false P0487 codes.
• Intake air leaks: Significant leaks after the MAF sensor can confuse EGR flow calculations and position feedback.
• Low system voltage or poor grounds: Weak battery, bad grounds, or charging system problems can affect EGR actuator performance.
• Aftermarket tuning or EGR modifications: EGR delete kits or poorly written tunes can cause the ECU to set P0487 because expected signals are missing.

Diagnosis: Step-by-Step Guide

You’ll want a basic tool set, a good scan tool with live data (and preferably Mode $06), a digital multimeter (DMM), and access to a wiring diagram. Carb/throttle body cleaner and a borescope are also helpful for inspecting carbon buildup.

1. Confirm the code and check for companions. Connect your scan tool, read all stored and pending codes, and note freeze-frame data. Look for related EGR or airflow codes like P0401 or P0402.
2. Perform a visual inspection. With the engine off, inspect the EGR throttle and EGR valve area. Look for damaged wiring, rubbed-through loom, loose connectors, or obvious vacuum hose issues.
3. Check connector and pins. Unplug the EGR throttle connector. Look for green corrosion, bent pins, moisture, or oil intrusion. Clean with electrical contact cleaner and reconnect securely.
4. Command the EGR throttle with a scan tool. Many scan tools let you activate the EGR throttle or perform an “EGR test.” Listen and feel for the actuator moving. If there’s no movement or it’s noisy/gritty, suspect the actuator or carbon buildup.
5. Monitor live data. Watch EGR throttle position (or EGR command vs. actual) while commanding it through the scan tool or while revving the engine. If commanded and actual don’t track closely, you’ve confirmed a control or feedback problem.
6. Test power, ground, and signal circuits. Using a wiring diagram, check for proper battery voltage and ground at the EGR throttle connector with a DMM. Backprobe the signal/feedback wire to verify it changes smoothly as the valve moves.
7. Inspect for carbon buildup. Remove the intake hose and visually inspect the EGR throttle plate and surrounding area. Heavy soot deposits can physically limit movement. Use a borescope if access is tight.
8. Clean the EGR throttle and passages. If buildup is present, carefully clean the throttle plate and bore with appropriate cleaner and a soft brush. Avoid forcing the plate on some electronically controlled units; follow manufacturer guidance.
9. Re-test and clear codes. After repairs or cleaning, clear the codes, perform a road test, and recheck for P0487. Monitor EGR data again to confirm normal operation.
10. Check Mode $06 (if available). Some scan tools show EGR-related test results under Mode $06. This can help confirm whether the system is passing internal self-tests.

Pro tip: Gently wiggle the harness and connector while monitoring EGR throttle data. If the readings jump or the engine stumbles, you likely have an intermittent wiring or connector fault that won’t show up on a static resistance test.

Possible Fixes & Repair Costs

Repairs for P0487 range from simple cleaning to replacing the EGR throttle assembly. Labor and parts cost vary by vehicle, engine type, and how buried the EGR components are. On many diesels, these parts are not cheap, and access can be tight.

• Clean EGR throttle and intake passages: Often the first step. DIY cost is mainly cleaner and time. Shop cost: about $100–$250 depending on labor hours.
• Repair or replace wiring/connectors: Splicing in new wire sections or replacing a connector can run $80–$250 depending on complexity and shop rates.
• Replace EGR throttle / EGR valve assembly: Parts can range from $150–$600+, plus 1–3 hours of labor. Typical total is $300–$900.
• Update ECU software (reflash): If a TSB applies, dealer reprogramming usually costs $100–$200.

Overall, you’re usually looking at a repair range of roughly $150–$900. Factors that affect cost include vehicle make, diesel vs. gas, part availability (OE vs. aftermarket), and whether additional components like the main EGR valve or DPF sensors are also failing.

Can I Still Drive With P0487?

In most cases, you can still drive with P0487 without immediate engine damage. The car will usually go into a mild “limp” mode or just run less efficiently. However, you may notice reduced power, more smoke on a diesel, and worse fuel economy. Long trips, towing, or high-load driving are not ideal until you fix the issue. If the engine feels like it’s severely down on power, misfiring, or smoking heavily, it’s best to limit driving and get it checked as soon as possible.

What Happens If You Ignore P0487?

Ignoring P0487 can lead to heavy carbon buildup in the intake, EGR passages, and possibly on valves, which can cause more drivability problems and additional codes. On diesel engines with a DPF, poor EGR function can increase soot loading and shorten the life of the DPF. Over time, you may face higher repair costs and fail emissions or inspection tests.

Last updated: February 13, 2026

Vehicles Commonly Affected by P0487

P0487 is especially common on modern diesel engines that use an EGR throttle plate. You’ll often see it on:

• Ford: Power Stroke diesels and some EcoBlue/Transit diesel engines.
• Chevrolet/GMC: Duramax-powered trucks and vans with advanced EGR and DPF systems.
• Dodge/Ram: Cummins and VM Motori diesels, particularly those with EGR coolers and DPF.
• Volkswagen/Audi: TDI engines where EGR throttles and intake manifolds are prone to soot buildup.
• BMW, Mercedes-Benz, and other European diesels: Similar EGR throttle designs that can suffer from carbon and actuator issues.
• Some gasoline engines: Certain models with electronic EGR throttles can also set P0487, though it’s less common than on diesels.