What Does B1408 Mean?
This code indicates the Body Control Module (BCM) has detected a short to battery voltage in the driver's power window up circuit. The BCM monitors the switch and motor control circuits, and when voltage is present on the up circuit when it should not be, this fault is set. This typically means positive battery voltage is reaching the circuit through an unintended path, causing continuous or erratic window operation.
Common Causes
40%
Damaged or chafed wiring harness between driver's door and body causing short to power
30%
Faulty driver's window master switch with internal short to power
20%
Water intrusion in door panel causing corrosion and short circuit in wiring or connectors
10%
Failed window motor with internal short or damaged motor connector terminals
Diagnostic Steps
1
Step 1: Perform visual inspection of the driver's door harness in the door jamb area where it flexes during opening/closing, looking for chafed, melted, or damaged insulation. Check for any exposed copper wire contacting other wires or metal surfaces
2
Step 2: Disconnect the driver's window master switch connector and use a digital multimeter to check for battery voltage on the window up circuit wire at the BCM side with ignition on. If voltage is still present, the short is in the harness; if voltage disappears, the switch is faulty
3
Step 3: If harness is suspect, disconnect the window motor connector and recheck for voltage on the up circuit. This isolates whether the short is between BCM and motor, or within the motor itself
4
Step 4: Remove the door panel and inspect all wiring, connectors, and components inside the door for signs of water damage, corrosion, pinched wires, or contact with metal brackets. Pay special attention to wire routing near window regulator mechanisms
5
Step 5: Use a wiring diagram to trace the specific up circuit wire color and perform continuity tests between the circuit and known battery voltage sources to pinpoint the exact location of the short
6
Step 6: After repair, clear the code, cycle the window through full up and down operations multiple times, and verify the code does not return with a retest
Estimated Repair Cost
$100 - $450
Parts + labor, varies by vehicle and location
This code indicates the Body Control Module (BCM) has detected a short to battery voltage in the driver's power window up circuit. The BCM monitors the switch and motor control circuits, and when voltage is present on the up circuit when it should not be, this fault is set. This typically means posi...
The most common cause of B1408 (Driver Power Window Up Circuit Short To Battery) is: Damaged or chafed wiring harness between driver's door and body causing short to power
Typical repair costs for B1408 range from $100 to $450, depending on the vehicle, location, and whether you do it yourself or go to a shop.
This is safe to drive with as it only affects power window operation. The window may operate intermittently, remain stuck, or move unexpectedly, which could be inconvenient but does not present a safety hazard requiring immediate repair.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to B1408 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
Body Control and Power Accessories
Difficulty
Type
Manufacturer
Recommended Tools
OBD2 Scanner
A quality scan tool helps you read codes, view live data, and clear faults.
