B1452 Wiper Switch Short to Battery
Diagnostic trouble code B1452 indicates a short to battery voltage in the wiper wash/delay switch circuit. The body control module (BCM) detects an abnormal battery voltage on the input circuit when the switch is at rest or in a position that should not produce that signal. This manufacturer-specific code is commonly associated with Toyota vehicles, where the system monitors wiper switch resistance and voltage to detect opens or shorts.
1. Commonly Affected Makes
2. Most Common Causes
- Faulty combination wiper/washer switch with internal short
- Wiring in the switch circuit shorted to battery voltage
- Corroded, damaged, or bridged terminals at the switch or module connector
- Damaged body control module (BCM) with internal failure
3. Symptoms You Will Notice
- Wipers operate continuously or at wrong speed
- Washer spray activates without command
- Wiper or washer functions completely inoperative
4. Step-by-Step Diagnosis
Check for technical service bulletins (TSBs) related to B1452 for the specific vehicle.
Visually inspect the wiper/washer switch connector and wiring for damage, corrosion, or shorts.
Test the switch resistance per manufacturer specs; replace if out of range.
Check for battery voltage on the signal wire with the switch off; if present, repair short to power.
If all else passes, suspect a faulty BCM and perform further module diagnostics.
5. Frequently Asked Questions
Is it safe to drive?▼
Yes, the vehicle is generally safe to drive, but wiper/washer functions may be erratic or inoperative, which can be a safety hazard in rain or when visibility is reduced.
How much does it cost to fix?▼
Repair costs typically range from $100 to $400, depending on whether the switch, wiring repair, or BCM replacement is needed.