B1794
Low Severity (Level 1)Lamp Headlamp Low-Beam Circuit Failure
B1794 usually means lamp Headlamp Low-Beam Circuit Failure.
Can you still drive with B1794?
✅Safe to drive — this is an informational or minor issue. Schedule diagnosis at your convenience.
Typical repair cost: $20 – $600
Severity Level 1 — 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
- Headlight warning message on instrument cluster display
- Warning light or message on dashboard related to the headlight system
- Headlights flickering, not working on one side, or not switching between high/low beam
- Diagnostic trouble code (DTC) stored in module memory
Possible Causes
- Failed headlight bulb/ballast — internal fault from age, heat cycling, and vibration
- Damaged wiring or corroded connector in the headlight system circuit
- Blown fuse for the headlight system circuit — check before replacing components
- Faulty control module driving the headlight bulb/ballast
- Loose or corroded ground point shared by the headlight 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 ($45-132 at shop, free at auto parts store for basic scan)
- Visually inspect the headlight system wiring harness and connectors — look for chafed wires, melted insulation, green corrosion, loose pins, or rodent damage (often free to check yourself, $116 diagnostic fee at shop)
- Replace headlight bulb/ballast if testing confirms it has failed — use OEM quality, avoid the cheapest no-name aftermarket parts that fail in a year ($20-600)
- Check and replace any blown fuses in the headlight system fuse circuit — if fuse blows again, there's still a short that needs to be found ($1-11 for fuses)
- Perform a wiggle test on the headlight system wiring harness while monitoring live data — see if the fault returns when you move the harness at different points ($0-114 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 B1794 mean?
B1794 stands for "Lamp Headlamp Low-Beam Circuit Failure". B1794 usually means lamp Headlamp Low-Beam Circuit Failure.
Can you drive with B1794?
Safe to drive — this is an informational or minor issue. Schedule diagnosis at your convenience.
How much does it cost to fix B1794?
Repair costs for B1794 typically range from $20 to $600, 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 ($45-132 at shop, free at auto parts store for basic scan); Visually inspect the headlight system wiring harness and connectors — look for chafed wires, melted insulation, green corrosion, loose pins, or rodent damage (often free to check yourself, $116 diagnostic fee at shop); Replace headlight bulb/ballast if testing confirms it has failed — use OEM quality, avoid the cheapest no-name aftermarket parts that fail in a year ($20-600).
Will B1794 clear itself?
Explore Repair Costs
Related OBD-II Codes
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