What Does B1599 Mean?
This code indicates the Body Control Module (BCM) has detected an electrical short to ground in the passenger seat autoglide forward switch circuit. The autoglide feature allows the seatback to automatically move forward for easier rear seat access. The BCM detected voltage on the switch circuit is lower than expected, indicating the circuit is grounded when it should not be.
Common Causes
45%
Damaged wiring or chafed insulation in the seat wiring harness causing short to ground against seat frame
30%
Failed autoglide forward switch with internal short to ground
15%
Corroded or moisture-damaged connector terminals creating ground path
10%
Failed Body Control Module with internal circuit fault
Diagnostic Steps
1
Step 1: Perform visual inspection of passenger seat base and seatback area for obvious wiring damage, pinched harnesses against seat rails, or damaged connectors. Look for signs of moisture intrusion or corrosion at all seat switch connectors.
2
Step 2: Disconnect the autoglide forward switch connector and measure resistance from the switch signal wire to ground using a digital multimeter. Reading should be >10k ohms (open circuit). If resistance is low (<5 ohms), circuit is shorted between connector and BCM.
3
Step 3: With switch still disconnected, measure resistance of the switch itself between signal terminal and ground terminal in both pressed and unpressed positions. Switch should show open circuit when not pressed and closed circuit (near 0 ohms) only when pressed. Replace switch if faulty.
4
Step 4: If switch tests good, inspect the wiring harness from switch to BCM by carefully moving seat through full range of motion while monitoring resistance to ground. Focus on areas where harness passes through seat tracks and pivot points where chafing commonly occurs.
5
Step 5: Check BCM connector pins for corrosion, bent terminals, or moisture. Clean or repair as needed. If all wiring and switch test good, suspect BCM internal fault.
6
Step 6: Clear codes, verify repair by operating autoglide function through multiple cycles and confirm no codes return after test drive with seat movement.
Estimated Repair Cost
$150 - $650
Parts + labor, varies by vehicle and location
This code indicates the Body Control Module (BCM) has detected an electrical short to ground in the passenger seat autoglide forward switch circuit. The autoglide feature allows the seatback to automatically move forward for easier rear seat access. The BCM detected voltage on the switch circuit is ...
The most common cause of B1599 (Passenger's Seatback Autoglide Forward Switch Circuit Short to Ground) is: Damaged wiring or chafed insulation in the seat wiring harness causing short to ground against seat frame
Typical repair costs for B1599 range from $150 to $650, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Safe to drive as this affects only a convenience feature. The autoglide function may not operate properly, but manual seat adjustment should still work. Repair at convenience within reasonable timeframe.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to B1599 to identify the root cause.
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Quick Info
Category
Body
System
Body Control / Comfort and Convenience
Difficulty
Type
Manufacturer
Recommended Tools
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