What Does B1592 Mean?
This code indicates the Body Control Module (BCM) has detected an open circuit in the autolamp delay decrease switch or its associated wiring. The autolamp system keeps exterior lights illuminated for a preset time after the vehicle is turned off and exited. The BCM is unable to receive the signal to decrease the delay timer, suggesting a break in the circuit between the control switch and the BCM.
Common Causes
40%
Open circuit or broken wire in the autolamp delay decrease switch wiring harness between the switch and BCM
30%
Faulty autolamp delay control switch with internal open circuit
20%
Corroded or loose electrical connector at the autolamp switch or BCM
10%
Failed Body Control Module unable to properly monitor the circuit
Diagnostic Steps
1
Step 1: Perform visual inspection of the autolamp delay control switch (typically located on turn signal stalk or dashboard) and check for physical damage, loose connections, or moisture intrusion at the connector
2
Step 2: Using a digital multimeter, check for continuity on the autolamp delay decrease circuit wire from the switch connector to the BCM connector with ignition off; should read less than 5 ohms resistance if circuit is intact
3
Step 3: At the autolamp switch connector (disconnected), test the switch itself by actuating the delay decrease button while measuring continuity across the appropriate terminals per wiring diagram; switch should close circuit when pressed
4
Step 4: Inspect BCM connector for corrosion, pushed-back pins, or terminal damage; clean terminals with electrical contact cleaner and verify proper pin seating and retention
5
Step 5: If all wiring and connections test good, perform voltage reference test at BCM side of circuit with switch disconnected; BCM should provide 5V or 12V reference voltage depending on manufacturer design
6
Step 6: Clear codes, reconnect all components, cycle autolamp delay function through all positions, and verify code does not return; test autolamp delay timer functionality to confirm repair
Estimated Repair Cost
$75 - $350
Parts + labor, varies by vehicle and location
This code indicates the Body Control Module (BCM) has detected an open circuit in the autolamp delay decrease switch or its associated wiring. The autolamp system keeps exterior lights illuminated for a preset time after the vehicle is turned off and exited. The BCM is unable to receive the signal t...
The most common cause of B1592 (Autolamp Delay Decrease Circuit Open) is: Open circuit or broken wire in the autolamp delay decrease switch wiring harness between the switch and BCM
Typical repair costs for B1592 range from $75 to $350, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Safe to continue driving as this only affects the convenience feature that keeps exterior lights on after exiting the vehicle. No immediate safety risk, though the autolamp delay timer may not function as intended or may remain at default setting.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to B1592 to identify the root cause.
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Quick Info
Category
Body
System
Exterior Lighting Control System
Difficulty
Type
Manufacturer
Recommended Tools
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