What Does B1506 Mean?
This diagnostic trouble code indicates that the Body Control Module (BCM) has detected an abnormal short-to-ground condition in the right turn signal lamp circuit. The BCM monitors current flow through the turn signal circuits and sets this code when it detects excessive current draw or zero resistance to ground, indicating the circuit is directly connected to ground before reaching the bulb. This typically occurs due to damaged wiring, corroded connectors, or faulty lamp sockets allowing current to bypass the intended load path.
Common Causes
40%
Damaged or chafed wiring harness between BCM and right turn signal lamp creating direct ground contact
30%
Corroded or moisture-damaged turn signal bulb socket causing internal short to ground
15%
Failed right turn signal bulb with internal short circuit to ground pin
10%
Pinched or damaged wiring at body connector points or behind rear bumper/taillight assembly
5%
Water intrusion in taillight assembly causing ground fault through circuit board or housing
Diagnostic Steps
1
Step 1: Perform visual inspection of right turn signal lamp assembly, bulb socket, and wiring. Check for corrosion, moisture, damaged insulation, or pinched wires. Remove bulb and inspect socket contacts for damage or discoloration.
2
Step 2: Using a digital multimeter set to resistance mode, disconnect the right turn signal lamp connector at the taillight assembly. Measure resistance between the turn signal circuit wire (BCM side) and vehicle ground. Should read infinite resistance (open circuit). A low or zero reading confirms short to ground in harness.
3
Step 3: If harness tests good, reconnect and measure resistance across the lamp socket terminals with bulb removed. Should read open circuit. If shorted, replace socket. If socket is good, test bulb independently for internal short between filament and ground shell.
4
Step 4: If wiring shows short to ground, disconnect intermediate connectors working back toward BCM to isolate the fault location. Check for wire damage at common chafe points: body grommets, behind bumper, near suspension components, and trailer hitch areas.
5
Step 5: After identifying and repairing the short circuit, clear codes and activate right turn signal using bidirectional controls or turn signal switch. Verify proper operation and confirm no codes return. Measure current draw should be within specification (typically 1.5-2.5 amps per bulb depending on type).
Estimated Repair Cost
$75 - $400
Parts + labor, varies by vehicle and location
This diagnostic trouble code indicates that the Body Control Module (BCM) has detected an abnormal short-to-ground condition in the right turn signal lamp circuit. The BCM monitors current flow through the turn signal circuits and sets this code when it detects excessive current draw or zero resista...
The most common cause of B1506 (Lamp Turn Signal Right Circuit Short To Ground) is: Damaged or chafed wiring harness between BCM and right turn signal lamp creating direct ground contact
Typical repair costs for B1506 range from $75 to $400, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Vehicle is drivable but right turn signal functionality is compromised, creating a significant safety hazard as other drivers cannot see your turning intentions. Repair should be completed immediately to maintain safe vehicle operation and avoid traffic citations.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to B1506 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
Exterior Lighting System
Difficulty
Type
Manufacturer
Recommended Tools
OBD2 Scanner
A quality scan tool helps you read codes, view live data, and clear faults.
