B1318
Medium SeverityBattery Voltage Low
Body/Electrical System
What Does B1318 Mean?
The body control module detects low battery voltage.
Common Fix
Replace battery or alternator
Estimated Cost (DIY)
$100 - $300
Symptoms
- ⚠️Various electrical malfunctions
- ⚠️Slow power windows
- ⚠️Dim interior lights
- ⚠️BCM warning
Common Causes
How to Diagnose B1318
- 1Test battery voltage
- 2Test alternator output
- 3Check for parasitic drain
OEM Diagnostic Flowchart
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B1318 requires a scanner that reads body modules — basic code readers won't see it.
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Related Resources
Repair guides, symptom pages, and wiring diagrams related to B1318.
Exact Repair Workflows
Browse →Open the exact repair flow most commonly associated with B1318 on this vehicle.
Open the exact repair flow most commonly associated with B1318 on this vehicle.
Open the exact repair flow most commonly associated with B1318 on this vehicle.
Open the exact repair flow most commonly associated with B1318 on this vehicle.
Open the exact repair flow most commonly associated with B1318 on this vehicle.
Open the exact repair flow most commonly associated with B1318 on this vehicle.
OEM Manual Evidence
Browse →A L L Diagnostic Trouble Codes ( DTC ) — 2012 Ford Truck F 550 4WD Super Duty V10-6.8L Service Manual | Operation CHARM Operation CHARM : C...
A L L Diagnostic Trouble Codes ( DTC ) — 2012 Ford Truck Flex AWD V6-3.5L Turbo Service Manual | Operation CHARM Operation CHARM : Car repa...
A L L Diagnostic Trouble Codes ( DTC ) — 2012 Ford Truck Flex FWD V6-3.5L Service Manual | Operation CHARM Operation CHARM : Car repair man...
A L L Diagnostic Trouble Codes ( DTC ) — 2012 Ford Truck Transit Connect L4-2.0L Service Manual | Operation CHARM Operation CHARM : Car rep...
Exact Vehicle Hubs
Browse →Open the exact vehicle hub for a repair workflow commonly associated with B1318.
Open the exact vehicle hub for a repair workflow commonly associated with B1318.
Open the exact vehicle hub for a repair workflow commonly associated with B1318.
Open the exact vehicle hub grounded by OEM manual evidence related to B1318.
Open the exact vehicle hub grounded by OEM manual evidence related to B1318.
Open the exact vehicle hub grounded by OEM manual evidence related to B1318.
Wiring Diagram Paths
Browse →Open the exact alternator diagram cluster for a vehicle that commonly triggers B1318.
Open the exact starter diagram cluster for a vehicle that commonly triggers B1318.
Open the exact alternator diagram cluster for a vehicle that commonly triggers B1318.
Open the exact starter diagram cluster for a vehicle that commonly triggers B1318.
Open the exact alternator diagram cluster for a vehicle that commonly triggers B1318.
Open the exact starter diagram cluster for a vehicle that commonly triggers B1318.
Related Codes
Frequently Asked Questions
- How do I test for parasitic drain?
- With engine off, put a multimeter in series with the battery negative cable. Anything over 50mA indicates a drain.
- Can a weak battery cause multiple codes?
- Yes — low voltage causes erratic behavior in multiple modules, often setting numerous codes. Fix the battery first and see if codes clear.
Related Repair Guides
If your vehicle has triggered B1318, these DIY repair guides may help: