A vacuum leak; An air restriction in the intake air path or exhuast; A faulty positive crankcase ventilation (PCV) valve; Damaged/failed/dirty throttle body; Internal engine problem; Failed PCM

Read the code and freeze-frame data with an OBD-II scanner; Check the connector and wiring of the part named in the code; Test the part with scanner live data or a multimeter, using the values in the repair manual; Fix the cause, clear the code and test-drive

P0506 on Honda Civic FC: Idle Control System RPM Lower Than Expected

Short answer: P0506 means “Idle Control System RPM Lower Than Expected”. The car’s computer has found a fault in the Engine system and turns on the Check engine light (MIL). First check: read the code and freeze-frame data with an OBD-II scanner.

Standard OBD-II code Same meaning on all cars (SAE J2012). Not checked against this car’s factory manual.

Code: P0506
System: Engine
Dashboard light: Check engine light (MIL)
Applies to: Generic OBD-II meaning. Not every code is used by this car.
Confidence: medium (generic OBD-II definition, not checked against the factory manual for this car)
Source: obd-codes.com

Symptoms and when it is set

Check engine light on

Likely causes

A vacuum leak
An air restriction in the intake air path or exhuast
A faulty positive crankcase ventilation (PCV) valve
Damaged/failed/dirty throttle body
Internal engine problem
Failed PCM

What to check, in order

Read the code and freeze-frame data with an OBD-II scanner
Check the connector and wiring of the part named in the code
Test the part with scanner live data or a multimeter, using the values in the repair manual
Fix the cause, clear the code and test-drive

Related on this car

Same code on other cars

← P0505 P0507 →

Clearing the code does not fix the fault. If it comes back, the problem is still there. For brakes, airbags and steering, see a trained mechanic.