What Does B2591 Mean?
This code indicates that the Body Control Module (BCM) did not receive the expected detent position signal from a latch mechanism during an unlatch operation. The detent signal confirms that a mechanical component (typically a door, hood, tailgate, or seat latch) has reached its fully unlatched position. The BCM monitors this feedback signal to verify proper latch operation and may affect related systems like interior lighting, security, or power functions.
Common Causes
40%
Faulty latch assembly with worn or damaged detent switch or position sensor
30%
Broken or damaged wiring harness between latch assembly and BCM, causing open circuit or intermittent connection
20%
Misaligned or mechanically binding latch preventing detent from reaching proper position
10%
Defective Body Control Module (BCM) not properly reading detent signal
Diagnostic Steps
1
Step 1: Identify which specific latch is setting the code by reviewing freeze frame data and operating each door, hood, and tailgate while monitoring live data for detent signal status
2
Step 2: Perform visual inspection of the suspect latch assembly and detent mechanism for physical damage, broken components, binding, or misalignment. Check for proper mechanical operation and audible detent click
3
Step 3: Using a digital multimeter, backprobe the latch connector and measure voltage/continuity on the detent signal wire during manual unlatch operation. Expected reading: voltage change or continuity change when detent position is reached (typically 0V to 5V or 0V to 12V depending on system)
4
Step 4: Inspect wiring harness from latch to BCM for chafing, corrosion, water intrusion, or broken wires. Pay special attention to flex points in doors and hinges. Perform wiggle test while monitoring signal
5
Step 5: If wiring and latch mechanical operation are confirmed good, substitute known-good latch assembly or perform resistance/voltage test on detent switch according to manufacturer specifications
6
Step 6: Clear codes, cycle the latch through multiple operations, and verify proper detent signal reception in live data. Test related functions (interior lights, security system) to confirm full repair
Estimated Repair Cost
$150 - $650
Parts + labor, varies by vehicle and location
This code indicates that the Body Control Module (BCM) did not receive the expected detent position signal from a latch mechanism during an unlatch operation. The detent signal confirms that a mechanical component (typically a door, hood, tailgate, or seat latch) has reached its fully unlatched posi...
The most common cause of B2591 (Detent Signal Missing During Unlatch) is: Faulty latch assembly with worn or damaged detent switch or position sensor
Typical repair costs for B2591 range from $150 to $650, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Generally safe to drive, but affected latch may not secure properly or may trigger false security alarms and drain battery. If related to door latches, there is potential risk of door opening unexpectedly while driving. Repair within 1-2 weeks or sooner if door latching is affected.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to B2591 to identify the root cause.
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Quick Info
Category
Body
System
Body Control and Latch System
Difficulty
Type
Generic (SAE)
Recommended Tools
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