OBD Guide

P256C

Engine Idle Speed Selector Sensor/Switch Circuit Low

P256C is an OBD-II diagnostic trouble code meaning: Engine Idle Speed Selector Sensor/Switch Circuit Low. Common causes: faulty idle speed selection sensor, open or short circuit in the sensor circuit. Estimated repair cost: $17–67.

Severity
⚠️ Medium
Can you drive?
Yes, but get it checked soon
Approx. repair cost
$17–67 (est.)

Symptoms

  • Unstable idle speed
  • Engine stalling at idle
  • Check Engine Light Illuminates
  • Reduced engine power
  • Problems starting the engine

Causes

  • Faulty idle speed selection sensor
  • Open or short circuit in the sensor circuit
  • Poor contacts or corrosion in connectors
  • Problems with the engine ECU
  • Faulty relay or fuse

How to Fix

  1. Check sensor voltage and resistance to specifications
  2. Inspect the wiring harness and connectors for damage.
  3. Check fuses and relays associated with the sensor circuit
  4. Replace the faulty sensor if necessary
  5. Reflash the ECU if there are no hardware faults

Related codes

Error P256C by Vehicle Brand

FAQ

What does the P256C code mean?

P256C is an OBD-II diagnostic trouble code that indicates: Engine Idle Speed Selector Sensor/Switch Circuit Low

What causes a P256C error code?

The most common causes of P256C include: Faulty idle speed selection sensor; Open or short circuit in the sensor circuit; Poor contacts or corrosion in connectors; Problems with the engine ECU.

How do I fix a P256C diagnostic trouble code?

To fix P256C: Check sensor voltage and resistance to specifications. Inspect the wiring harness and connectors for damage.. Check fuses and relays associated with the sensor circuit. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with P256C?

Yes, but get it checked soon

How much does it cost to fix P256C?

The estimated repair cost for P256C is $17–67. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat