What Does B1547 Mean?
This code indicates the Body Control Module (BCM) has detected a malfunction in the power window master switch circuit, typically located in the driver's door. The BCM monitors the electrical signals from the master switch assembly and has identified an abnormal voltage, resistance, or communication failure in the circuit. This affects the ability to control one or more power windows from the master switch panel.
Common Causes
45%
Faulty power window master switch assembly with internal contact wear, corrosion, or circuit board failure
30%
Damaged or corroded wiring harness connections between master switch and BCM, often in driver's door boot area
15%
Water intrusion or moisture damage to master switch assembly causing short circuits or corrosion
10%
Body Control Module internal fault or corrupted programming related to power window control
Diagnostic Steps
1
Step 1: Perform visual inspection of the driver's door master window switch assembly for obvious damage, water intrusion, melted connectors, or signs of overheating. Remove switch assembly and inspect connector pins for corrosion or bent terminals.
2
Step 2: Using a digital multimeter, test for proper ground continuity at the master switch connector (typically 0-0.5 ohms to chassis ground) and verify battery voltage supply (12-14V) with ignition on at the appropriate pins per wiring diagram.
3
Step 3: Disconnect master switch connector and check for continuity through the door boot wiring harness between the door jamb connectors with multimeter. Flex the harness while testing to identify intermittent breaks, looking for resistance changes indicating damaged wires.
4
Step 4: With master switch reconnected and ignition on, use scan tool's bidirectional controls to command individual window functions while monitoring BCM data stream for proper switch input signal changes (typically 0V, 5V, or 12V depending on manufacturer).
5
Step 5: If all wiring and power/ground tests pass, substitute a known-good master switch assembly to confirm switch failure, or test BCM output signals at the switch connector to verify BCM is sending proper control voltages.
6
Step 6: After repair, clear codes, cycle all windows through complete up/down operations multiple times, perform window auto-up/down relearn procedure if equipped, and verify no codes return after test drive.
Estimated Repair Cost
$150 - $650
Parts + labor, varies by vehicle and location
This code indicates the Body Control Module (BCM) has detected a malfunction in the power window master switch circuit, typically located in the driver's door. The BCM monitors the electrical signals from the master switch assembly and has identified an abnormal voltage, resistance, or communication...
The most common cause of B1547 (Power Window Master Circuit Failure) is: Faulty power window master switch assembly with internal contact wear, corrosion, or circuit board failure
Typical repair costs for B1547 range from $150 to $650, 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 braking systems. Repair at convenience, though loss of window control can be problematic in emergency situations requiring ventilation or communication with outside the vehicle.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to B1547 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 Convenience Systems
Difficulty
Type
Manufacturer
Recommended Tools
OBD2 Scanner
A quality scan tool helps you read codes, view live data, and clear faults.
