OBD Guide

P1246

Alternator Load Input Failed

P1246 is an OBD-II diagnostic trouble code meaning: Alternator Load Input Failed. Common causes: generator malfunction, open or short circuit in load signal circuit. Estimated repair cost: $33–167.

Severity
⚠️ Medium
Can you drive?
Limited driving only, diagnose soon
Approx. repair cost
$33–167 (est.)

Symptoms

  • Unstable engine operation at idle
  • Flashing or dimming of headlights when load changes
  • Battery charge lamp lights up
  • RPM dips when turning on headlights, air conditioning or other consumers
  • Increased fuel consumption

Causes

  • Generator malfunction
  • Open or short circuit in load signal circuit
  • Poor contact in the generator or ECU connectors
  • Voltage regulator relay malfunction
  • ECU problems (rare)

How to Fix

  1. Check the voltage and charging current of the generator
  2. Inspect the load signal circuit for damage
  3. Check and clean the contacts in the generator and ECU connectors
  4. Test the voltage regulator relay
  5. If necessary, replace the generator or its components

Related codes

Error P1246 by Vehicle Brand

FAQ

What does the P1246 code mean?

P1246 is an OBD-II diagnostic trouble code that indicates: Alternator Load Input Failed

What causes a P1246 error code?

The most common causes of P1246 include: Generator malfunction; Open or short circuit in load signal circuit; Poor contact in the generator or ECU connectors; Voltage regulator relay malfunction.

How do I fix a P1246 diagnostic trouble code?

To fix P1246: Check the voltage and charging current of the generator. Inspect the load signal circuit for damage. Check and clean the contacts in the generator and ECU connectors. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with P1246?

Limited driving only, diagnose soon

How much does it cost to fix P1246?

The estimated repair cost for P1246 is $33–167. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat