What Does B1459 Mean?
This code indicates the Body Control Module (BCM) has detected an open circuit in the control circuit for the windshield washer pump motor relay coil. The BCM is unable to energize the relay that supplies power to the washer pump motor, meaning the relay coil winding has no complete electrical path to ground or power. This prevents the windshield washer system from operating when activated.
Common Causes
40%
Failed windshield washer pump relay with open coil winding
30%
Broken or corroded wiring between BCM and washer pump relay coil terminals
20%
Corroded or loose relay socket/connector terminals preventing electrical contact
10%
Failed BCM relay driver circuit unable to control relay coil
Diagnostic Steps
1
Step 1: Locate the windshield washer pump relay in the fuse/relay box (typically under hood or dashboard). Visually inspect the relay socket for corrosion, melted plastic, or damaged terminals. Remove the relay and inspect pins for damage or corrosion.
2
Step 2: With relay removed and ignition ON, use a multimeter to measure voltage at the relay socket power supply terminal (typically 85 or 86). Should read battery voltage (12-14V). Then activate washer switch and measure voltage at the BCM control terminal - should toggle between 0V and 12V or show ground path depending on relay type.
3
Step 3: Test the removed relay coil resistance using an ohmmeter across coil terminals (typically 85 and 86). Should read between 50-200 ohms depending on relay specification. Infinite resistance indicates open coil. Also apply 12V directly to coil terminals to verify relay clicking and contact closure.
4
Step 4: If relay tests good, trace and inspect wiring harness from BCM connector to relay socket for breaks, chafing, or pinched wires. Check all connectors for corrosion, bent pins, or poor terminal tension. Repair or replace damaged wiring as needed.
5
Step 5: Clear codes and operate washer system. Monitor live data for relay command status from BCM while activating washer switch. If BCM shows command but relay doesn't energize with known-good relay installed, suspect BCM internal driver failure.
6
Step 6: After repairs, verify washer pump operation, clear all codes, and perform multiple activation cycles to confirm repair. Road test if necessary and rescan for code return.
Estimated Repair Cost
$75 - $350
Parts + labor, varies by vehicle and location
This code indicates the Body Control Module (BCM) has detected an open circuit in the control circuit for the windshield washer pump motor relay coil. The BCM is unable to energize the relay that supplies power to the washer pump motor, meaning the relay coil winding has no complete electrical path ...
The most common cause of B1459 (Wiper Washer Pump Motor Relay Coil Circuit Open) is: Failed windshield washer pump relay with open coil winding
Typical repair costs for B1459 range from $75 to $350, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Safe to continue driving, but impaired visibility cleaning capability reduces safety during inclement weather or when windshield becomes soiled. Repair at earliest convenience, especially before rainy seasons or long trips.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to B1459 to identify the root cause.
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Quick Info
Category
Body
System
Windshield Washer System
Difficulty
Type
Manufacturer
Recommended Tools
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