P1246
Alternator Load Input Failed
Severity
⚠️ MediumCan 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
- 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
- Test the voltage regulator relay
- If necessary, replace the generator or its components