What Does B1440 Mean?
This code indicates the Body Control Module (BCM) has detected an abnormal voltage condition in the wiper mode select switch circuit, specifically that the circuit is shorted directly to battery voltage (12V+). The BCM monitors the wiper switch inputs and expects specific voltage ranges for different switch positions; when it continuously sees battery voltage regardless of switch position, it sets this fault. This prevents proper wiper operation mode selection and may cause wipers to operate incorrectly or not at all.
Common Causes
35%
Damaged or chafed wiring harness causing direct short to power between multifunction switch and BCM
30%
Faulty multifunction switch with internal short to power circuit
20%
Water intrusion or corrosion in multifunction switch connector causing short circuit
10%
BCM internal failure with damaged input circuit
5%
Aftermarket accessory installation causing power feed into wiper circuit
Diagnostic Steps
1
Step 1: Perform visual inspection of multifunction switch connector and steering column wiring for obvious damage, corrosion, melted terminals, or water intrusion. Check for any aftermarket wiring taps near the steering column.
2
Step 2: Disconnect the multifunction switch connector and use a digital multimeter to measure voltage at the wiper mode select circuit terminal at the harness side (BCM side). Should read 0V with ignition on; if battery voltage is present, wiring harness has short to power.
3
Step 3: If no voltage found in Step 2, measure resistance between the switch-side wiper mode circuit terminal and battery positive with switch disconnected. Infinite resistance indicates good harness; low resistance confirms short to power in harness requiring trace and repair.
4
Step 4: If harness tests good, reconnect switch and backprobe the circuit while operating wiper switch through all positions. Voltage should vary predictably; constant 12V indicates faulty multifunction switch requiring replacement.
5
Step 5: Clear codes, test wiper operation through all modes, and verify no code return. Monitor BCM data stream for proper wiper switch input values during operation.
Estimated Repair Cost
$120 - $650
Parts + labor, varies by vehicle and location
This code indicates the Body Control Module (BCM) has detected an abnormal voltage condition in the wiper mode select switch circuit, specifically that the circuit is shorted directly to battery voltage (12V+). The BCM monitors the wiper switch inputs and expects specific voltage ranges for differen...
The most common cause of B1440 (Wiper Mode Select Switch Circuit Short To Battery) is: Damaged or chafed wiring harness causing direct short to power between multifunction switch and BCM
Typical repair costs for B1440 range from $120 to $650, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Vehicle is safe to drive but wiper functionality may be compromised or inoperative, which becomes a safety concern during rain or inclement weather. Repair should be completed before driving in conditions requiring windshield wipers.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to B1440 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
Windshield Wiper/Washer System
Difficulty
Type
Manufacturer
Recommended Tools
OBD2 Scanner
A quality scan tool helps you read codes, view live data, and clear faults.
