B1371 Code: Meaning, Symptoms, Causes & Fix

Overview

Code B1371 indicates a fault in Illuminated Entry Relay Circuit Failure, typically within body electronics and comfort modules.

Symptoms

related warning lamp illuminated
battery draw complaints
feature inoperative intermittently

Common causes

Broken terminal inside harness affecting illuminated entry relay circuit failure
Disconnected or loose connector
Connector pin damage/corrosion or harness stress near related components

How to diagnose B1371

Confirm B1371 and capture freeze-frame data with a professional scan tool.
Inspect wiring, connectors, and grounds related to illuminated entry relay circuit failure for obvious defects.
Use a continuity test from module pin to component to identify opens/high resistance.
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 B1371

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

Can you drive with B1371?

Most vehicles can be driven short-term with B1371, 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 (open) in the illuminated entry relay circuit failure circuit/system.
Apply the required relearn/adaptation procedure if specified by service information.
Road-test and verify B1371 remains cleared under the conditions that originally set the code.

Fix options

Repair open circuit and secure connector lock.
Restore continuity and verify pin tension.
Clear DTCs and verify with live data and completed drive cycle.

Typical repair cost

$160-$850

Common mistakes when diagnosing B1371

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.

B1371 in common vehicles

B1371 appears across makes such as Ford, Toyota, Honda, Chevrolet. Failure patterns differ by platform: wiring routes, software calibration, and component supplier revisions can change root cause.

Frequently asked questions

What causes B1371?

B1371 is commonly set by open faults affecting illuminated entry relay circuit failure.

How much does it cost to fix B1371?

For B1371, repair costs are typically $160-$850 depending on exact root cause, labor rates, and part quality.

Can I clear B1371 without repair?

You can clear B1371 temporarily, but the code usually returns until the underlying fault is corrected.