OBD Guide

B1256

Air Temperature External Sensor Circuit Short To Battery

B1256 is an OBD-II diagnostic trouble code meaning: Air Temperature External Sensor Circuit Short To Battery. Common causes: temperature sensor wiring harness damaged, short circuit in the sensor circuit. Estimated repair cost: $33–89.

Severity
⚠️ Medium
Can you drive?
Limited driving only, diagnose soon
Approx. repair cost
$33–89 (est.)

Symptoms

  • Incorrect outside temperature readings on the instrument panel
  • Climate control system malfunction
  • Check Engine Light Illuminates

Causes

  • Temperature sensor wiring harness damaged
  • Short circuit in the sensor circuit
  • Outside air temperature sensor malfunction
  • Oxidation or corrosion of sensor contacts

How to Fix

  1. Check the integrity of the temperature sensor wiring harness
  2. Check the resistance and voltage at the sensor
  3. Replace outside air temperature sensor if necessary
  4. Clean or replace oxidized contacts

Related codes

FAQ

What does the B1256 code mean?

B1256 is an OBD-II diagnostic trouble code that indicates: Air Temperature External Sensor Circuit Short To Battery

What causes a B1256 error code?

The most common causes of B1256 include: Temperature sensor wiring harness damaged; Short circuit in the sensor circuit; Outside air temperature sensor malfunction; Oxidation or corrosion of sensor contacts.

How do I fix a B1256 diagnostic trouble code?

To fix B1256: Check the integrity of the temperature sensor wiring harness. Check the resistance and voltage at the sensor. Replace outside air temperature sensor if necessary. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with B1256?

Limited driving only, diagnose soon

How much does it cost to fix B1256?

The estimated repair cost for B1256 is $33–89. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat