B1840
Low Severity (Level 2)Wiper Front Power Circuit Failure
B1840 usually means wiper Front Power Circuit Failure.
Can you still drive with B1840?
⚠️Short-distance driving is usually OK, but have this diagnosed within a week to prevent further damage.
Typical repair cost: $50 – $400
Severity Level 2 — Low
This code indicates a minor issue that is unlikely to cause immediate driveability problems. You can typically continue driving but should have the vehicle inspected at your earliest convenience.
Common Symptoms
- Windshield wipers not working, stuck mid-cycle, or only working on one speed
- Windshield wipers not functioning as expected
- Warning light or message on dashboard related to the wiper/washer system
- Diagnostic trouble code (DTC) stored in module memory
Possible Causes
- Failed wiper motor — internal fault from age, heat cycling, and vibration
- Damaged wiring or corroded connector in the wiper/washer system circuit
- Blown fuse for the wiper/washer system circuit — check before replacing components
- Faulty control module driving the wiper motor
- Loose or corroded ground point shared by the wiper/washer system
Common Fixes
- Scan vehicle with a professional-grade OBD2 scanner to read all stored codes and freeze frame data — note the conditions when the code set ($28-121 at shop, free at auto parts store for basic scan)
- Visually inspect the wiper/washer system wiring harness and connectors — look for chafed wires, melted insulation, green corrosion, loose pins, or rodent damage (often free to check yourself, $106 diagnostic fee at shop)
- Replace wiper motor if testing confirms it has failed — use OEM quality, avoid the cheapest no-name aftermarket parts that fail in a year ($50-400)
- Check and replace any blown fuses in the wiper/washer system fuse circuit — if fuse blows again, there's still a short that needs to be found ($4-18 for fuses)
- Perform a wiggle test on the wiper/washer system wiring harness while monitoring live data — see if the fault returns when you move the harness at different points ($0-146 diagnostic labor)
Estimated Repair Cost
These are estimated costs based on generic repair data. Actual costs may vary depending on your vehicle, location, and labor rates.
Frequently Asked Questions
What does B1840 mean?
B1840 stands for "Wiper Front Power Circuit Failure". B1840 usually means wiper Front Power Circuit Failure.
Can you drive with B1840?
Short-distance driving is usually OK, but have this diagnosed within a week to prevent further damage.
How much does it cost to fix B1840?
Repair costs for B1840 typically range from $50 to $400, depending on your vehicle make, model, and local labor rates. Common fixes include: Scan vehicle with a professional-grade OBD2 scanner to read all stored codes and freeze frame data — note the conditions when the code set ($28-121 at shop, free at auto parts store for basic scan); Visually inspect the wiper/washer system wiring harness and connectors — look for chafed wires, melted insulation, green corrosion, loose pins, or rodent damage (often free to check yourself, $106 diagnostic fee at shop); Replace wiper motor if testing confirms it has failed — use OEM quality, avoid the cheapest no-name aftermarket parts that fail in a year ($50-400).
Will B1840 clear itself?
Explore Repair Costs
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