P1245 Code: Meaning, Symptoms, Causes & Fix

Overview

P1245 is triggered when monitoring logic identifies an issue with Alternator Load Input Failed Low affecting powertrain controls.

Symptoms

reduced performance
increased fuel use
check engine light

Common causes

Signal pulled low by short-to-ground affecting alternator load input failed low
Sensor output out of expected lower range
Connector pin damage/corrosion or harness stress near related components

How to diagnose P1245

Confirm P1245 and capture freeze-frame data with a professional scan tool.
Inspect wiring, connectors, and grounds related to alternator load input failed low for obvious defects.
Compare live data against expected lower threshold and verify ground/reference circuits.
Check for related DTCs to identify the root-cause chain before replacing parts.
After repair, clear codes and confirm readiness monitors complete without recurrence.

Severity of code P1245

Moderate: This code is moderate severity: the vehicle may still operate, but fault progression can increase repair cost over time.

Can you drive with P1245?

Most vehicles can be driven short-term with P1245, but postpone heavy load/highway driving until repaired.

If the warning lamp is flashing or drivability/safety is affected, avoid driving and diagnose immediately.

How to fix it (step-by-step)

Repair obvious wiring/connector faults first to prevent repeat parts replacement.
Address the root fault mode (low) in the alternator load input failed low circuit/system.
Apply the required relearn/adaptation procedure if specified by service information.
Road-test and verify P1245 remains cleared under the conditions that originally set the code.

Fix options

Verify ground path and signal integrity.
Repair connector resistance issues.
Clear DTCs and verify with live data and completed drive cycle.

Typical repair cost

$200-$900

Common mistakes when diagnosing P1245

Replacing parts without verifying voltage, ground, and signal integrity first.
Ignoring related stored/pending codes that indicate upstream faults.
Skipping post-repair verification drive cycle and readiness checks.

P1245 in common vehicles

P1245 appears across makes such as Nissan, Hyundai, Kia, Volkswagen. Failure patterns differ by platform: wiring routes, software calibration, and component supplier revisions can change root cause.

Frequently asked questions

What causes P1245?

P1245 is commonly set by low faults affecting alternator load input failed low.

How much does it cost to fix P1245?

For P1245, repair costs are typically $200-$900 depending on exact root cause, labor rates, and part quality.

Can I clear P1245 without repair?

You can clear P1245 temporarily, but the code usually returns until the underlying fault is corrected.