What Does B2599 Mean?
DTC B2599 indicates that the Body Control Module (BCM) has detected an open circuit in the tailgate or liftgate release mechanism electrical circuit. This means there is a break in the electrical path between the BCM and the tailgate release actuator, preventing the system from operating the power release function. The BCM monitors the circuit and sets this code when it cannot complete the electrical path to ground or power.
Common Causes
40%
Broken or damaged wiring in the tailgate harness due to flexing at hinge points
30%
Failed tailgate release actuator/solenoid with internal open circuit
20%
Corroded or disconnected electrical connector at tailgate release actuator
10%
Faulty Body Control Module with internal circuit failure
Diagnostic Steps
1
Step 1: Perform a visual inspection of the tailgate release actuator connector and wiring harness, especially at the hinge areas where wiring flexes. Look for broken wires, corroded terminals, water intrusion, or disconnected plugs.
2
Step 2: Using a digital multimeter, test for continuity in the tailgate release circuit from the BCM connector to the actuator connector with the system unpowered. Check both power and ground circuits for opens (should read less than 5 ohms resistance).
3
Step 3: Disconnect the tailgate release actuator and measure its internal resistance across the actuator terminals. A normal actuator should show 2-10 ohms depending on manufacturer; infinite resistance indicates a failed open actuator.
4
Step 4: If wiring and actuator test good, check for voltage supply at the actuator connector while commanding the tailgate release function active using the scan tool bi-directional controls. Should see battery voltage when activated.
5
Step 5: Repair or replace the faulty component (wiring, connector, or actuator), clear the code, and cycle the tailgate release function multiple times to verify proper operation and confirm the code does not return.
Estimated Repair Cost
$150 - $450
Parts + labor, varies by vehicle and location
DTC B2599 indicates that the Body Control Module (BCM) has detected an open circuit in the tailgate or liftgate release mechanism electrical circuit. This means there is a break in the electrical path between the BCM and the tailgate release actuator, preventing the system from operating the power r...
The most common cause of B2599 (Tailgate Release Open Circuit) is: Broken or damaged wiring in the tailgate harness due to flexing at hinge points
Typical repair costs for B2599 range from $150 to $450, depending on the vehicle, location, and whether you do it yourself or go to a shop.
This code does not affect vehicle safety or driveability. The vehicle is safe to drive, but the power tailgate release function will not work, requiring manual operation of the tailgate latch until repaired.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to B2599 to identify the root cause.
OBDHut Mobile App
Scan codes directly from your car with the OBDHut app.
Coming Soon
Quick Info
Category
Body
System
Body Control and Convenience Systems
Difficulty
Type
Generic (SAE)
Recommended Tools
OBD2 Scanner
A quality scan tool helps you read codes, view live data, and clear faults.
