B1605
Low Severity (Level 2)Lamp Anti-Theft Indicator Circuit Short To Battery
B1605 usually means lamp Anti-Theft Indicator Circuit Short To Battery.
Can you still drive with B1605?
⚠️Short-distance driving is usually OK, but have this diagnosed within a week to prevent further damage.
Typical repair cost: $120 – $1000
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
- Engine cranks but won't start — immobilizer preventing start
- Alarm going off randomly or not arming
- Security system staying on or functioning when they shouldn't (powered continuously)
- Excessive current draw on the vehicle security/anti-theft system circuit (fuse may blow repeatedly)
Possible Causes
- Damaged wiring in the vehicle security/anti-theft system harness shorted to a 12V power source — wiring insulation chafed through from rubbing against metal body panels
- Water intrusion or corrosion in vehicle security/anti-theft system electrical connector causing internal short to battery voltage
- Failed security module — internal short to power within the component
- Aftermarket accessory installation tapped into the wrong circuit, back-feeding 12V
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 ($21-85 at shop, free at auto parts store for basic scan)
- Visually inspect the vehicle security/anti-theft system wiring harness and connectors — look for chafed wires, melted insulation, green corrosion, loose pins, or rodent damage (often free to check yourself, $140 diagnostic fee at shop)
- Repair or replace damaged section of wiring harness where short is located — solder and heat-shrink all connections, don't use crimp connectors on critical circuits ($193-430 depending on accessibility)
- If security module is internally shorted, replace with a quality OEM or OEM-equivalent aftermarket unit ($100-800)
- Clean all ground points related to the vehicle security/anti-theft system — remove bolt, sand contact surface to bare metal, apply dielectric grease, and torque to spec ($31-104 at shop)
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 B1605 mean?
B1605 stands for "Lamp Anti-Theft Indicator Circuit Short To Battery". B1605 usually means lamp Anti-Theft Indicator Circuit Short To Battery.
Can you drive with B1605?
Short-distance driving is usually OK, but have this diagnosed within a week to prevent further damage.
How much does it cost to fix B1605?
Repair costs for B1605 typically range from $120 to $1000, 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 ($21-85 at shop, free at auto parts store for basic scan); Visually inspect the vehicle security/anti-theft system wiring harness and connectors — look for chafed wires, melted insulation, green corrosion, loose pins, or rodent damage (often free to check yourself, $140 diagnostic fee at shop); Repair or replace damaged section of wiring harness where short is located — solder and heat-shrink all connections, don't use crimp connectors on critical circuits ($193-430 depending on accessibility).
Will B1605 clear itself?
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