What Does B1404 Mean?
This code indicates the Body Control Module (BCM) has detected an open circuit in the driver's power window down control circuit. An open circuit means there is a break in the electrical pathway that prevents current flow when the window down function is commanded. This affects the driver's door power window system and prevents the window from being lowered using the control switch.
Common Causes
40%
Broken or corroded wiring in the driver's door jamb area due to repeated flexing and exposure to the elements
30%
Failed driver door window switch with open contacts in the down position circuit
20%
Faulty BCM connection or corroded BCM connector terminals for window control circuits
10%
Damaged window motor connector or broken wire at the motor connection point
Diagnostic Steps
1
Step 1: Perform visual inspection of driver door wiring harness in the jamb area between door and body, checking for broken, chafed, or corroded wires especially where harness flexes during door opening
2
Step 2: Using a digital multimeter, check for continuity from the BCM connector (window down circuit terminal) to the driver door switch connector with all connectors disconnected and ignition off - should read less than 5 ohms resistance
3
Step 3: Test the driver window switch by disconnecting it and measuring resistance across the down switch terminals while activating the down position - should show continuity (near 0 ohms) when pressed, infinite resistance when released
4
Step 4: Inspect BCM connector terminals for corrosion, bent pins, or pushed-back terminals using a flashlight and terminal probe, and check for moisture intrusion in connector body
5
Step 5: If all wiring and connections test good, perform voltage drop test on the down circuit with switch activated - voltage drop exceeding 0.5V indicates high resistance connection requiring repair
6
Step 6: After repairs, clear codes, cycle window switch through all positions multiple times, and verify code does not return and window operates normally in both directions
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 driver's power window down control circuit. An open circuit means there is a break in the electrical pathway that prevents current flow when the window down function is commanded. This affects the driver's door pow...
The most common cause of B1404 (Driver Power Window Down Circuit Open) is: Broken or corroded wiring in the driver's door jamb area due to repeated flexing and exposure to the elements
Typical repair costs for B1404 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 as this does not affect vehicle operation or safety systems. Repair at your convenience, though delayed repair may result in inability to open driver window for ventilation or toll booth access.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to B1404 to identify the root cause.
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Quick Info
Category
Body
System
Body Electrical System - Power Window Control
Difficulty
Type
Manufacturer
Recommended Tools
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