Powertrain, generic · Auxiliary emission controls

P0487 EGR Throttle Control Circuit A/Open

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modePossible

Exhaust gas recirculation (EGR) routes part of the exhaust back into the intake to lower combustion temperature and NOx. The EGR throttle is a regulating flap ahead of the intake manifold on diesels: by closing partly it lowers manifold pressure below exhaust back pressure so that enough exhaust is recirculated, and it also helps filter regeneration and shuts off air at engine stop. It is usually a DC motor with position sensor. GM and Ford report this flap under P02E0 ff; no manufacturer document available to us uses this code. P0487 means its drive circuit is open or has a general circuit fault, detected by the output stage. The flap then stays open, so the EGR rate cannot be raised enough and filter regeneration may be blocked.

Likely causes

Connector at the flap corroded or loose, wire open
Flap actuator motor faulty (winding open)
Pneumatic version: vacuum converter faulty
Driver in the engine module

Symptoms

  • Check engine light on
  • Loss of power or limp mode possible
  • Shaking when the engine is switched off
  • Filter regeneration does not complete

Repair estimate

DifficultyMediumDIY possible
Parts and labour€80–500
Time0.5–2 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

egr throttle valvethrottle actuatoractuator wiringengine control module

Related codes

P0488P02E0P02E1P0403P0401

References: law.cornell.edu, ms-motorservice.com, patents.google.com.