B2104
Low Severity (Level 1)Door Passenger Key Cylinder Switch Failure
B2104 usually means door Passenger Key Cylinder Switch Failure.
Can you still drive with B2104?
✅Safe to drive — this is an informational or minor issue. Schedule diagnosis at your convenience.
Typical repair cost: $80 – $500
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
- Power door locks not responding to key fob or interior switch
- Door locks cycling (locking/unlocking) on their own while driving
- Power door locks not functioning as expected
- Diagnostic trouble code (DTC) stored in module memory
Possible Causes
- Failed door lock actuator — internal fault from age, heat cycling, and vibration
- Damaged wiring or corroded connector in the power door lock/latch system circuit
- Blown fuse for the power door lock/latch system circuit — check before replacing components
- Faulty control module driving the door lock actuator
- Loose or corroded ground point shared by the power door lock/latch system
- Broken wire in the door jamb wiring boot — harness flexes every time the door opens, eventually wires break inside the rubber boot
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 ($25-92 at shop, free at auto parts store for basic scan)
- Visually inspect the power door lock/latch system wiring harness and connectors — look for chafed wires, melted insulation, green corrosion, loose pins, or rodent damage (often free to check yourself, $60 diagnostic fee at shop)
- Inspect the wiring boot where it passes from the body into the door — this is the #1 failure point. Peel back the rubber boot and check for broken/cracked wires ($0 DIY inspection)
- Replace door lock actuator if testing confirms it has failed — use OEM quality, avoid the cheapest no-name aftermarket parts that fail in a year ($80-500)
- Check and replace any blown fuses in the power door lock/latch system fuse circuit — if fuse blows again, there's still a short that needs to be found ($3-17 for fuses)
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 B2104 mean?
B2104 stands for "Door Passenger Key Cylinder Switch Failure". B2104 usually means door Passenger Key Cylinder Switch Failure.
Can you drive with B2104?
Safe to drive — this is an informational or minor issue. Schedule diagnosis at your convenience.
How much does it cost to fix B2104?
Repair costs for B2104 typically range from $80 to $500, 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 ($25-92 at shop, free at auto parts store for basic scan); Visually inspect the power door lock/latch system wiring harness and connectors — look for chafed wires, melted insulation, green corrosion, loose pins, or rodent damage (often free to check yourself, $60 diagnostic fee at shop); Inspect the wiring boot where it passes from the body into the door — this is the #1 failure point. Peel back the rubber boot and check for broken/cracked wires ($0 DIY inspection).
Will B2104 clear itself?
Explore Repair Costs
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