OBD Guide

B1851

Climate Control Temperature Differential Circuit Short To Battery

B1851 is an OBD-II diagnostic trouble code meaning: Climate Control Temperature Differential Circuit Short To Battery. Common causes: short circuit in the sensor circuit, wiring harness damage. Estimated repair cost: $56–167.

Severity
⚠️ Medium
Can you drive?
Limited driving only, diagnose soon
Approx. repair cost
$56–167 (est.)

Symptoms

  • Incorrect operation of climate control
  • Uneven temperature distribution in the cabin
  • Constant fan operation at high speed

Causes

  • Short circuit in the sensor circuit
  • Wiring harness damage
  • Malfunction of the differential temperature sensor
  • Problems with the climate control unit

How to Fix

  1. Check the integrity of the wiring in the sensor circuit
  2. Measure sensor resistance
  3. Check the voltage at the sensor contacts
  4. Replace sensor if necessary
  5. Check the climate control control unit

Related codes

FAQ

What does the B1851 code mean?

B1851 is an OBD-II diagnostic trouble code that indicates: Climate Control Temperature Differential Circuit Short To Battery

What causes a B1851 error code?

The most common causes of B1851 include: Short circuit in the sensor circuit; Wiring harness damage; Malfunction of the differential temperature sensor; Problems with the climate control unit.

How do I fix a B1851 diagnostic trouble code?

To fix B1851: Check the integrity of the wiring in the sensor circuit. Measure sensor resistance. Check the voltage at the sensor contacts. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with B1851?

Limited driving only, diagnose soon

How much does it cost to fix B1851?

The estimated repair cost for B1851 is $56–167. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat