What Does B1307 Mean?
This code indicates the Body Control Module (BCM) or Engine Control Module (ECM) has detected a short to battery voltage in the oil level sensor switch circuit. The control module is receiving constant battery voltage on the signal wire when it should see a variable voltage or ground signal based on oil level. This electrical fault prevents accurate oil level monitoring and may disable the low oil level warning system.
Common Causes
40%
Damaged or chafed wiring harness causing the signal wire to contact battery voltage
30%
Failed oil level sensor with internal short to power
20%
Corroded or damaged oil level sensor connector allowing cross-circuit contact
10%
Control module internal fault or water damage causing incorrect voltage detection
Diagnostic Steps
1
Step 1: Perform visual inspection of the oil level sensor connector and wiring harness for damage, corrosion, bent pins, or signs of chafing against sharp edges or hot components. Check for oil contamination in the connector.
2
Step 2: Disconnect the oil level sensor connector and use a digital multimeter to measure voltage on the signal wire at the harness side connector with ignition on. Reading should be 0-0.5V (pulldown/ground reference). If battery voltage (12V+) is present, trace wiring for short to power.
3
Step 3: With sensor disconnected and ignition off, measure resistance between the sensor signal wire and battery positive at the harness. Resistance should be infinite (open circuit). Low resistance indicates a short to battery in the wiring harness.
4
Step 4: If wiring tests pass, reconnect harness and check the oil level sensor itself by measuring resistance across its terminals per manufacturer specifications. Replace sensor if out of specification or showing continuity to case ground when it shouldn't.
5
Step 5: Repair or replace damaged wiring/connectors as needed, ensuring proper routing away from heat sources and sharp edges. Use dielectric grease on connectors to prevent corrosion.
6
Step 6: Clear codes, cycle ignition, and verify proper oil level sensor operation through live data monitoring. Confirm code does not return and oil level warning system functions correctly.
Estimated Repair Cost
$150 - $450
Parts + labor, varies by vehicle and location
This code indicates the Body Control Module (BCM) or Engine Control Module (ECM) has detected a short to battery voltage in the oil level sensor switch circuit. The control module is receiving constant battery voltage on the signal wire when it should see a variable voltage or ground signal based on...
The most common cause of B1307 (Oil Level Switch Circuit Short To Battery) is: Damaged or chafed wiring harness causing the signal wire to contact battery voltage
Typical repair costs for B1307 range from $150 to $450, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Vehicle is generally safe to drive short distances, but the low oil level warning system is compromised and cannot alert you to dangerous oil levels. Check oil level manually before driving and avoid extended trips until repaired to prevent potential engine damage from undetected low oil.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to B1307 to identify the root cause.
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Quick Info
Category
Body
System
Engine Monitoring System / Body Control System
Difficulty
Type
Manufacturer
Recommended Tools
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