B2373 — LED #1 Circuit Short to Battery #

Note: The code label may vary depending on the vehicle manufacturer (OEM). Below are some known variations:

• LED #1 Circuit Short to Battery (Ford, General Motors)
• LED Module 1 Circuit High (Toyota)
• LED Circuit 1 High Voltage (Nissan)
• LED Array 1 Shorted to Power (Hyundai/Kia)

Summary of Code B2373 #

DTC B2373 is an OBD-II diagnostic trouble code indicating that the vehicle’s onboard computer has detected a short circuit to battery voltage in the circuit controlling the first LED (Light Emitting Diode) module. In practical terms, the circuit responsible for powering a specific LED—typically used in modern lighting systems such as daytime running lights or interior ambient lighting—is receiving a higher voltage than expected, usually due to a direct connection with the battery or a wiring fault. This can result in erratic or non-functional lighting and, in some cases, may trigger warnings or disable certain lighting features as a safety measure. The code does not specify which LED is affected unless referenced in OEM documentation, so always check the service manual for pinpoint location. Addressing this code quickly is important to restore full lighting function and prevent potential electrical hazards.

Common Symptoms for Code B2373 #

When code B2373 is set, drivers or technicians may notice several visible or operational symptoms. Since this code relates to an LED circuit, most symptoms revolve around lighting performance and related alerts. Typical signs include:

• LED lighting (such as DRLs, interior lights, or tail lamps) not working or stuck on
• Warning lights or messages on the dashboard (e.g., “Check Lighting System”)
• Flickering, dimming, or inconsistent operation of affected LEDs
• In some vehicles, other lighting circuits may be deactivated as a protective measure
• Possible battery drain if the circuit remains energized when the vehicle is off

Likely Causes for Code B2373 #

The B2373 code is most often triggered by electrical issues that cause the LED circuit to receive direct battery voltage when it should not. Causes can range from simple wiring faults to internal control module failures. The most common root causes, in order of likelihood, are:

1. Damaged, pinched, or shorted wiring harness supplying the LED
2. Connector corrosion or water intrusion at the LED or module
3. Failed or internally shorted LED module
4. Faulty Body Control Module (BCM) or Lighting Control Module
5. Incorrect or aftermarket installation of LED components

Step-by-Step Diagnosis for Code B2373 #

Diagnosing B2373 involves systematically checking the circuit, from the power source to the affected LED module. Proper safety precautions should be taken to avoid electrical shock or further damage. Here’s a recommended diagnostic approach:

• 1. Use a scan tool to confirm the presence of B2373 and to check for additional related codes.
• 2. Visually inspect the wiring and connectors leading to the LED module for signs of damage, pinching, or corrosion.
• 3. Disconnect the LED module and check for battery voltage at the connector when the lighting circuit is off (there should be none).
• 4. Using a wiring diagram, trace the circuit from the module back to the control unit, checking for any short to battery voltage along the way.
• 5. Test the LED module independently (if possible) to rule out internal shorting.
• 6. Inspect and, if necessary, test the Body Control Module or Lighting Control Module for output faults.
• 7. If aftermarket components were recently installed, verify compatibility and correct installation.

Possible Repairs for Code B2373 #

The correct repair for B2373 will depend on the actual cause identified during diagnosis. Addressing the root issue is crucial to prevent recurrence. Possible fixes include:

• Repairing or replacing damaged or shorted wiring in the LED circuit
• Cleaning or replacing corroded connectors and ensuring proper sealing against moisture
• Replacing a faulty or shorted LED module with an OEM-approved part
• Replacing or reprogramming the Body Control Module or Lighting Control Module if found defective
• Correcting any improper installations of aftermarket lights or accessories

Is It Safe to Drive with Code B2373? #

Limited. While code B2373 rarely poses an immediate threat to vehicle safety or drivability, driving with this code is not advisable for extended periods. Persistent electrical faults can lead to unreliable lighting operation (which is a safety concern, especially at night or in poor visibility), potential battery drain, and in rare cases, risk of electrical fire if the short is severe. Prompt diagnosis and repair are recommended.

Vehicles Most Commonly Affected by Code B2373 #

This code is most frequently found in vehicles that use extensive LED lighting controlled by modules, especially those from the mid-2010s onward. While it can appear in various makes, experience shows it is more often reported in:

• Ford F-Series (F-150, F-250, etc.)
• Chevrolet Silverado and GMC Sierra
• Toyota Camry and Corolla (with LED lighting packages)
• Nissan Altima and Sentra (with OEM LED lighting)
• Hyundai Sonata and Elantra

Common Mistakes & Best Practices for Code B2373 #

Diagnosing and repairing B2373 can be straightforward, but common errors can lead to wasted time or repeat failures. To ensure a lasting fix, keep these points in mind:

• Overlooking the possibility of water intrusion or corrosion at connectors, especially after car washes or heavy rain
• Replacing the LED module without first checking and repairing the wiring harness
• Ignoring TSBs (Technical Service Bulletins) or OEM updates related to known lighting issues
• Using non-OEM or incompatible LED replacements, which may not meet circuit specifications
• Skipping a full system scan for related codes that could indicate broader control module issues

Express FAQ: Code B2373 #

Have questions about B2373? Here are quick answers to the most common concerns:

• Q: Will clearing the code with a scan tool fix the problem?
  A: No. The code will return unless the underlying electrical fault is repaired. Treating the symptom without addressing the cause can lead to further issues.
• Q: Can an aftermarket LED trigger this code?
  A: Yes. If the replacement does not match OEM specifications or is installed incorrectly, it can cause circuit faults and trigger B2373.
• Q: Is this code covered under warranty?
  A: If your vehicle is within the OEM warranty and no aftermarket modifications have been made, repairs for this code are often covered. Check with your dealer or service advisor.