OBD Guide

B1850

Climate Control Temperature Differential Circuit Open

B1850 is an OBD-II diagnostic trouble code meaning: Climate Control Temperature Differential Circuit Open. Common causes: broken wiring harness, oxidation of sensor contacts. 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
  • Lack of response to temperature changes
  • Constant fan operation at one speed
  • Error indication on the instrument panel

Causes

  • Broken wiring harness
  • Oxidation of sensor contacts
  • Malfunction of the differential temperature sensor
  • Problems in the climate control module

How to Fix

  1. Check the integrity of the wiring harness
  2. Clean sensor contacts
  3. Replace differential temperature sensor
  4. Check climate control module

Related codes

FAQ

What does the B1850 code mean?

B1850 is an OBD-II diagnostic trouble code that indicates: Climate Control Temperature Differential Circuit Open

What causes a B1850 error code?

The most common causes of B1850 include: Broken wiring harness; Oxidation of sensor contacts; Malfunction of the differential temperature sensor; Problems in the climate control module.

How do I fix a B1850 diagnostic trouble code?

To fix B1850: Check the integrity of the wiring harness. Clean sensor contacts. Replace differential temperature sensor. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with B1850?

Limited driving only, diagnose soon

How much does it cost to fix B1850?

The estimated repair cost for B1850 is $56–167. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat