Powertrain, generic (extended)

P2171 Exhaust Pressure Regulator Vent Solenoid Control Circuit High

Check engine lightOn

EmissionsRelevant

Drive cycleNot required

Limp modeNo

P2171 means the module sees too much voltage on the control line of the exhaust pressure regulator vent solenoid, usually because the line touches battery voltage or the solenoid shorts internally. No manufacturer documents this exact code publicly. The closest evidence comes from its sibling: Jaguar Land Rover assigns P2170 to the solenoid of the active exhaust valve on its petrol models, so on those cars P2171 belongs to the same part with the opposite electrical fault. CARB requires output components like this to be checked for circuit faults whenever they can affect emissions or other monitors. Checking means measuring the control wire with the solenoid unplugged for foreign voltage and the coil for a too low resistance. The driver mostly notices a MIL and an exhaust sound that no longer switches.

Likely causes

Control wire shorted to a battery-fed circuit

Solenoid coil shorted internally

Output stage in the engine control module faulty

Symptoms

Check engine lamp on
Exhaust flap stays in one position

Repair estimate

DifficultyMediumWorkshop job

Parts and labour€50–700

Time0.5–2.5 h

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

Parts involved

exhaust pressure regulatorwiring harnessengine control module

Related codes

P2169 P2170

References: law.cornell.edu, static.nhtsa.gov, static.nhtsa.gov.