OBD Code B2599: Tailgate Release Open Circuit

Q: What does OBD code B2599 mean?

Tailgate Release Open Circuit. The tailgate release circuit has a break in its electrical connection, like a severed phone line preventing communication. Your vehicle can't send the signal to unlock or release the tailgate.

Q: What are the symptoms of fault code B2599?

Tailgate won't open or release electrically, Tailgate release button is unresponsive, No clicking sound from tailgate actuator when button pressed

Q: How do I fix OBD fault code B2599?

Inspect and reseat the electrical connector at the button switch for corrosion or loose pins.. Check for broken, pinched, or corroded wires between the switch and tailgate actuator using a multimeter.. Test the solenoid with direct 12V power; if it doesn't click, replace the faulty actuator.

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What This Actually Means

In plain language — no jargon

The tailgate release circuit has a break in its electrical connection, like a severed phone line preventing communication. Your vehicle can't send the signal to unlock or release the tailgate.

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Symptoms You May Notice

3 known symptoms for this code

Tailgate won't open or release electrically

Tailgate release button is unresponsive

No clicking sound from tailgate actuator when button pressed

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How Your ECU Detects This

Technical sensor logic and voltage thresholds

The ECU monitors voltage and current flow through the tailgate release solenoid circuit when the release button is activated. It expects a complete circuit with proper voltage delivery to the actuator. An open circuit causes voltage to drop or remain absent, triggering the fault code.

Voltage & Parameter Thresholds

Parameter	Normal Range	Fault Condition
Tailgate Release Circuit Voltage	12V present at solenoid when activated	0V or <5V when button pressed
Circuit Continuity	<10 ohms resistance in complete circuit	Infinite resistance (open circuit detected)

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Diagnostic & DIY Fix Guide

Check these in order — from cheapest to most complex

1

Tailgate release switch connector

Inspect and reseat the electrical connector at the button switch for corrosion or loose pins.

2

Tailgate wiring harness

Check for broken, pinched, or corroded wires between the switch and tailgate actuator using a multimeter.

3

Tailgate release solenoid actuator

Test the solenoid with direct 12V power; if it doesn't click, replace the faulty actuator.

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When to See a Professional Mechanic

Not all fault codes are safe to DIY

Code B2599 is a low-severity fault. Your vehicle is generally safe to drive to a workshop for diagnosis. However, do not ignore it indefinitely — low-severity codes often indicate developing problems that become expensive if neglected. Book a diagnostic appointment within 2–4 weeks. If you notice any additional symptoms (rough running, power loss, unusual smells), treat it as higher priority.

Safety note: OBD-II codes identify the system or circuit where a fault was detected — they do not always identify the exact failed component. A professional mechanic using live sensor data will diagnose the root cause more accurately than replacing parts based on the code alone.

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How to Clear Code B2599

What happens after you fix the fault

Once the fault is repaired, B2599 can be cleared using any OBD-II scanner. Connect the scanner, navigate to "Clear Codes" or "Erase DTCs," and confirm. The check engine light turns off immediately.

The code will return if the root cause was not actually fixed. The ECM re-detects the fault within 1–3 drive cycles and sets the code again.

✅ Safe to Clear When

Fault has been diagnosed and repaired
You want to confirm the repair worked
Code appeared after a sensor was cleaned

⚠️ Do Not Clear When

Preparing for an emissions/PUC test
Root cause is still undiagnosed
Check engine light is flashing

Emissions test note: Clearing codes resets OBD readiness monitors. Most vehicles need 50–100 km of mixed driving before monitors complete. Do not clear codes immediately before an emissions or PUC inspection.