What Does B1317 Mean?
This code indicates that the Body Control Module (BCM) has detected a battery voltage reading that exceeds the normal operating range, typically above 16 volts. This condition affects the vehicle's electrical system and can potentially damage sensitive electronic components. The BCM monitors system voltage continuously and sets this code when sustained overvoltage is detected, most commonly caused by charging system regulation failures.
Safety Warning
This condition is unsafe to ignore as sustained overvoltage can damage or destroy electronic modules, blow fuses, damage the battery, and potentially cause electrical fires. Vehicle should be diagnosed and repaired immediately; avoid extended driving until charging system regulation is restored to normal specifications.
Common Causes
45%
Faulty voltage regulator or failed alternator with internal regulator malfunction causing overcharging
25%
Corroded or loose battery terminals and charging system connections causing false high voltage readings
20%
Defective BCM voltage sensing circuit or internal BCM fault producing incorrect voltage readings
10%
Failed battery with internal short or damaged cells causing abnormal voltage spikes
Diagnostic Steps
1
Step 1: With engine running at idle, use a digital multimeter to measure battery voltage directly at battery terminals. Normal charging voltage should be 13.5-14.8V. If reading exceeds 15.5V, proceed to alternator testing.
2
Step 2: Increase engine RPM to 2000 and monitor voltage with multimeter. Voltage should remain stable between 13.5-14.8V. If voltage rises above 15.5V or continues climbing, alternator voltage regulation is faulty.
3
Step 3: Inspect all battery cable connections, alternator mounting, and ground straps for corrosion, looseness, or damage. Clean and tighten all connections, then retest voltage with engine running.
4
Step 4: Perform alternator diode and charging system ripple test using multimeter AC voltage setting across battery terminals with engine running. AC ripple should be less than 0.5V AC; higher readings indicate failed diodes.
5
Step 5: If voltage readings are normal at battery but code persists, backprobe BCM voltage sense wire and compare reading to battery terminal voltage to identify potential wiring or BCM sensing issue.
6
Step 6: After repairs, clear codes, run engine through various loads (headlights, HVAC, accessories) and monitor voltage remains stable between 13.5-14.8V to confirm proper charging system regulation.
Estimated Repair Cost
$150 - $800
Parts + labor, varies by vehicle and location
This code indicates that the Body Control Module (BCM) has detected a battery voltage reading that exceeds the normal operating range, typically above 16 volts. This condition affects the vehicle's electrical system and can potentially damage sensitive electronic components. The BCM monitors system ...
The most common cause of B1317 (Battery Voltage High) is: Faulty voltage regulator or failed alternator with internal regulator malfunction causing overcharging
Typical repair costs for B1317 range from $150 to $800, depending on the vehicle, location, and whether you do it yourself or go to a shop.
This condition is unsafe to ignore as sustained overvoltage can damage or destroy electronic modules, blow fuses, damage the battery, and potentially cause electrical fires. Vehicle should be diagnosed and repaired immediately; avoid extended driving until charging system regulation is restored to normal specifications.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to B1317 to identify the root cause.
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Quick Info
Category
Body
System
Electrical Charging System
Difficulty
Type
Manufacturer
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