What Does B1247 Mean?
This code indicates the Body Control Module (BCM) has detected an open circuit in the panel dimmer switch circuit, which controls the brightness of the instrument panel and interior lighting. An open circuit means there is a break in the electrical pathway preventing proper communication between the dimmer switch and the BCM. This prevents the driver from adjusting dashboard and interior light brightness levels.
Common Causes
40%
Faulty panel dimmer switch with internal open circuit or worn contacts
30%
Broken or disconnected wiring between dimmer switch and BCM
20%
Corroded or damaged connector at dimmer switch or BCM
10%
Failed BCM with internal circuit fault on dimmer input
Diagnostic Steps
1
Step 1: Perform visual inspection of the panel dimmer switch, its connector, and associated wiring for obvious damage, corrosion, or loose connections. Check connector terminals for bent pins or corrosion.
2
Step 2: Using a digital multimeter, check for continuity across the dimmer switch by disconnecting it and testing resistance while rotating through its full range. Should show smooth resistance change from approximately 0-500 ohms without infinite resistance (open).
3
Step 3: With dimmer switch disconnected, check for voltage supply at the switch connector (typically 5V or 12V reference) and verify ground circuit continuity to BCM using wiring diagram for vehicle-specific pin identification.
4
Step 4: If switch and connectors test good, check continuity of the signal wire from dimmer switch connector back to the BCM connector with harness disconnected at both ends to isolate wiring faults.
5
Step 5: If all wiring and switch test good, suspect BCM internal fault. Verify BCM ground connections are clean and tight, then consider BCM replacement or professional reprogramming if available.
6
Step 6: After repair, clear codes, cycle dimmer switch through full range, and verify code does not return and dashboard lights dim properly.
Estimated Repair Cost
$75 - $450
Parts + labor, varies by vehicle and location
This code indicates the Body Control Module (BCM) has detected an open circuit in the panel dimmer switch circuit, which controls the brightness of the instrument panel and interior lighting. An open circuit means there is a break in the electrical pathway preventing proper communication between the...
The most common cause of B1247 (Panel Dim Switch Circuit Open) is: Faulty panel dimmer switch with internal open circuit or worn contacts
Typical repair costs for B1247 range from $75 to $450, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Safe to continue driving. This is a convenience issue that prevents adjustment of dashboard illumination brightness but does not affect vehicle operation or safety systems. Repair at earliest convenience to maintain proper night-time visibility comfort.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to B1247 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
Interior Lighting Control System
Difficulty
Type
Manufacturer
Recommended Tools
OBD2 Scanner
A quality scan tool helps you read codes, view live data, and clear faults.
