What Does B1696 Mean?
This code indicates that the Body Control Module (BCM) has detected a short to ground in the autolamp (automatic headlight) control circuit. The autolamp system automatically turns headlights on/off based on ambient light conditions, and the BCM has identified that the circuit voltage is being pulled to ground when it should be at a higher reference voltage. This electrical fault prevents proper automatic headlight operation.
Common Causes
45%
Damaged or chafed wiring harness causing wire insulation breakdown and contact with vehicle ground
30%
Faulty autolamp sensor or photocell with internal short to ground
15%
Corroded or water-damaged connector terminals causing ground path
10%
Failed Body Control Module with internal circuit damage
Diagnostic Steps
1
Step 1: Perform visual inspection of the autolamp sensor (typically located on dashboard near windshield or integrated into rearview mirror) and its wiring harness for obvious damage, chafing, or water intrusion. Check all connectors for corrosion, bent pins, or moisture.
2
Step 2: Disconnect the autolamp sensor connector and use a digital multimeter to measure resistance between the autolamp control circuit wire (at BCM side of harness) and vehicle ground. Reading should be infinite (OL); any measurable resistance indicates a short to ground in the wiring.
3
Step 3: If wiring tests good, measure resistance across the autolamp sensor itself. Compare readings to manufacturer specifications (typically several thousand ohms varying with light exposure). A near-zero ohm reading indicates a failed sensor with internal short.
4
Step 4: Inspect wiring harness routing through doors, A-pillars, and firewall areas where wire chafing commonly occurs. Gently flex and manipulate harness while monitoring resistance to identify intermittent shorts.
5
Step 5: If all wiring and sensor test within specifications, suspect BCM internal failure. Verify proper BCM ground connections and power supply voltages before condemning the module.
6
Step 6: After repair, clear codes, actuate autolamp system by covering/uncovering sensor with varying light conditions, and verify code does not return and headlights operate automatically as designed.
Estimated Repair Cost
$100 - $600
Parts + labor, varies by vehicle and location
This code indicates that the Body Control Module (BCM) has detected a short to ground in the autolamp (automatic headlight) control circuit. The autolamp system automatically turns headlights on/off based on ambient light conditions, and the BCM has identified that the circuit voltage is being pulle...
The most common cause of B1696 (Autolamp On Circuit Short To Ground) is: Damaged or chafed wiring harness causing wire insulation breakdown and contact with vehicle ground
Typical repair costs for B1696 range from $100 to $600, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Safe to continue driving as manual headlight control remains functional. The only consequence is loss of automatic headlight operation, requiring manual headlight activation. Non-urgent repair, but should be addressed to restore convenience features and ensure headlights are not accidentally left off in dark conditions.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to B1696 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
Lighting System (Autolamp/Automatic Headlight Control)
Difficulty
Type
Manufacturer
Recommended Tools
OBD2 Scanner
A quality scan tool helps you read codes, view live data, and clear faults.
