AutoCodes – Generic – B1594

B1594 Code - Autolamp Delay Decrease Circuit Short To Ground

Quick Answer

The Body Control Module (BCM) monitors the Autolamp Delay. Common causes include Faulty Autolamp Delay, Autolamp Delay harness is open or shorted, Autolamp Delay circuit poor electrical connection. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

What it means: B1594 indicates Autolamp Delay Decrease Circuit Short To Ground.
Common causes: Common causes include Faulty Autolamp Delay, Autolamp Delay harness is open or shorted, Autolamp Delay circuit poor electrical connection.
Severity: High - diagnose this code as soon as possible.
Can I drive?: Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

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Code Popularity 4,272

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

What is this?

Table of contents Created and updated by William Orellana on May 05, 2019

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code B1594 Description

The Body Control Module (BCM) monitors the Autolamp Delay. The BCM sets the OBDII code when the Autolamp Delay is not to factory specifications.

OBDII Code B1594 - Autolamp Delay Decrease Circuit Short To Ground - AutoCodes.com — B1594 Code - Autolamp Delay Decrease Circuit Short To Ground

What does this mean?

What are the Possible Causes of the DTC B1594?

Faulty Autolamp Delay
Autolamp Delay harness is open or shorted
Autolamp Delay circuit poor electrical connection
Faulty Body Control Module (BCM)

How to Fix the DTC B1594?

Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the B1594 code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.

Need more information about the B1594 code?

Need more information on how to fix the B1594 code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the B1594 code diagnosed by a professional: Find a repair shop in your area

About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.

Frequently Asked Questions about B1594 Code

1. What are common symptoms of OBDII code B1594 (Autolamp Delay Decrease Circuit Short To Ground)?

The common symptoms of this code may include malfunctioning autolamp delay system, dim or flickering headlights, and a blown fuse related to the lighting system.

2. What can cause the Autolamp Delay Decrease Circuit Short To Ground code to trigger?

The code B1594 can be triggered by a short circuit to ground in the autolamp delay decrease circuit, damaged wiring in the lighting system, or a faulty lighting control module.

3. How can I diagnose the Autolamp Delay Decrease Circuit Short To Ground issue?

To diagnose this issue, you can use a diagnostic scanner to retrieve the trouble codes, visually inspect the wiring for any damage, test the lighting control module, and perform a continuity test on the circuit.

4. Can I still drive my vehicle with the B1594 code present?

While it may be possible to drive with this code present, it is not recommended as it can lead to unpredictable behavior of the lighting system, potentially compromising your safety on the road.

5. How do I repair the Autolamp Delay Decrease Circuit Short To Ground issue?

To repair this problem, you will need to locate and repair the short to ground in the autolamp delay circuit, replace any damaged wiring, and possibly replace the lighting control module if it is found to be faulty.

6. Will resetting the trouble codes make the B1594 code disappear permanently?

Resetting the trouble codes may temporarily clear the B1594 code, but if the underlying issue is not addressed and repaired, the code is likely to reappear once the system detects the fault again.

7. Can a DIY enthusiast fix the Autolamp Delay Decrease Circuit Short To Ground problem?

While some DIY enthusiasts may have the skills to diagnose and repair this issue, it is recommended to seek professional help, especially when dealing with electrical components to ensure the problem is properly resolved.

8. Is the Autolamp Delay Decrease Circuit Short To Ground a common issue in certain vehicle makes and models?

This specific OBDII code may be more prevalent in certain vehicle makes and models that have autolamp delay systems, as the wiring and components related to these systems can be prone to wear and damage over time.

9. Are there any preventive maintenance tips to avoid the B1594 code in the future?

Regularly inspecting the lighting system wiring for any signs of wear, ensuring proper installation of aftermarket lighting components, and avoiding water damage to the lighting system can help prevent the occurrence of the B1594 trouble code.

10. How long does it typically take to repair the Autolamp Delay Decrease Circuit Short To Ground issue?

The repair time for this issue can vary depending on the extent of the damage and the accessibility of the components. It may take anywhere from a few hours to a full day to diagnose and repair the Autolamp Delay Decrease Circuit Short To Ground problem.