P256A

Engine Idle Speed Selector Sensor/Switch Circuit/Open

Severity

⚠️ Medium

Can you drive?

Yes, but get it checked soon

Approx. repair cost

$17–56 (est.)

Symptoms

Unstable idle speed
Spontaneous change in engine speed
Stalls at idle
Check Engine light comes on
Increased or decreased idle speed

Causes

Broken wires in the sensor circuit
Idle speed sensor/switch malfunction
Poor contact in the sensor connector
Short circuit to ground or power
Malfunction of the engine control unit (rare)

How to Fix

Check the integrity of the sensor wires and connectors
Check sensor resistance (compare with factory specifications)
Check the presence of power and ground at the sensor connector
Replace idle speed sensor if necessary
Reflash or replace the ECU if it malfunctions (extremely rare)

Related codes

P0505 P0506 P0507