OBD Guide

B1312

Lamp Headlamp Input Circuit Short To Battery

B1312 is an OBD-II diagnostic trouble code meaning: Lamp Headlamp Input Circuit Short To Battery. Common causes: damage to control circuit wire insulation, faulty headlight relay. Estimated repair cost: $33–167.

Severity
⚠️ Medium
Can you drive?
Do not drive — repair immediately
Approx. repair cost
$33–167 (est.)

Symptoms

  • Incorrect headlight operation
  • Flashing headlights
  • Automatic headlight system failure
  • Illuminated fault indicator on the instrument panel

Causes

  • Damage to control circuit wire insulation
  • Faulty headlight relay
  • Short circuit in wiring harness
  • Problems with the body electronics control unit
  • Corrosion of contacts in connectors

How to Fix

  1. Conduct a visual inspection of the wiring harness and connectors for damage.
  2. Check the resistance and continuity of the headlight control circuit
  3. Test the headlight relay for proper operation
  4. Check the voltage at the corresponding terminals of the control unit
  5. Replace damaged wires or components as necessary

Related codes

FAQ

What does the B1312 code mean?

B1312 is an OBD-II diagnostic trouble code that indicates: Lamp Headlamp Input Circuit Short To Battery

What causes a B1312 error code?

The most common causes of B1312 include: Damage to control circuit wire insulation; Faulty headlight relay; Short circuit in wiring harness; Problems with the body electronics control unit.

How do I fix a B1312 diagnostic trouble code?

To fix B1312: Conduct a visual inspection of the wiring harness and connectors for damage.. Check the resistance and continuity of the headlight control circuit. Test the headlight relay for proper operation. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with B1312?

Do not drive — repair immediately

How much does it cost to fix B1312?

The estimated repair cost for B1312 is $33–167. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat