OBD Guide

P1256

Engine Coolant Temperature Sensor Open/Short To Positive

P1256 is an OBD-II diagnostic trouble code meaning: Engine Coolant Temperature Sensor Open/Short To Positive. Common causes: broken wiring to the temperature sensor, short circuit to positive in the sensor circuit. Estimated repair cost: $6–28.

Severity
⚠️ Medium
Can you drive?
Limited driving only, diagnose soon
Approx. repair cost
$6–28 (est.)

Symptoms

  • Incorrect temperature readings on the dashboard
  • Increased fuel consumption
  • Difficulty starting a hot engine
  • Non-steel idle operation
  • Turning on the Check Engine Light

Causes

  • Broken wiring to the temperature sensor
  • Short circuit to positive in the sensor circuit
  • Faulty coolant temperature sensor
  • Corrosion or poor contact in the sensor connector
  • Engine control unit malfunction

How to Fix

  1. Visual inspection of the sensor wiring and connector for damage
  2. Checking the sensor resistance at different temperatures
  3. Checking voltage and continuity using a multimeter
  4. Replacing a faulty coolant temperature sensor
  5. Clean connector contacts or replace if necessary

Related codes

Error P1256 by Vehicle Brand

FAQ

What does the P1256 code mean?

P1256 is an OBD-II diagnostic trouble code that indicates: Engine Coolant Temperature Sensor Open/Short To Positive

What causes a P1256 error code?

The most common causes of P1256 include: Broken wiring to the temperature sensor; Short circuit to positive in the sensor circuit; Faulty coolant temperature sensor; Corrosion or poor contact in the sensor connector.

How do I fix a P1256 diagnostic trouble code?

To fix P1256: Visual inspection of the sensor wiring and connector for damage. Checking the sensor resistance at different temperatures. Checking voltage and continuity using a multimeter. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with P1256?

Limited driving only, diagnose soon

How much does it cost to fix P1256?

The estimated repair cost for P1256 is $6–28. Actual cost depends on your vehicle, location, and labor rates.

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