Chevrolet-specific code — factory diagnostic data| DTC Data Sheet | |
| Code | B1325 |
| Vehicle | Chevrolet Silverado 1500 (2007-2019) |
| Engine | All |
| System | CHARGING SYSTEM |
| Fault type | Circuit |
| Official meaning | Device Power Voltage Low (Battery / Charging) |
Definition source: Chevrolet factory description. Diagnostic guidance is based on factory-defined fault logic for this code.
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B1325 Quick Answer
B1325 on a Silverado is set by the body control module when supply voltage drops below ~10.5V or sees a sustained low-voltage condition while the truck is running. Common causes in order: a tired battery (most common, especially in 4-5 year-old originals), a worn alternator, parasitic draw discharging the battery overnight, or corroded battery cables. Almost always paired with C0561 (StabiliTrak disabled) and other system warnings.
What Does B1325 Mean on a Chevy Silverado 1500?
The Chevrolet Silverado 1500 (2007-2019) stores B1325 when the condition described above is met. This guide focuses on the All configurations. Diagnostic priorities and likely root causes differ from the generic SAE definition because of platform-specific failure patterns documented below.
Symptoms
- Slow cranking on cold mornings
- Multiple dash warning lights (ABS, StabiliTrak, BCM)
- Codes like C0561, B1325, U-codes set simultaneously
- Interior lights dim when accessories are switched on
- Battery dies overnight or after 2-3 days of sitting
Common Causes (Most Likely on This Model First)
- Failing battery (most common). OE batteries in Silverados last 4-6 years. By year 5 the cold-cranking amps have dropped to roughly half. Voltage holds at idle but drops under load. Load-test confirms.
- Failing alternator. Output drops below 13.5V at idle with electrical accessories on. Worn brushes, failed diode trio, or worn voltage regulator. Charging-system test at any auto parts store is free.
- Parasitic draw. Truck that sits for a few days runs the battery flat. Common parasitic-draw culprits on Silverados: aftermarket alarm, faulty BCM (keeps a module awake), bad door switch keeping interior lights on intermittently.
- Corroded or loose battery cable. The negative cable terminal especially — corrosion causes voltage drop under load. Check by measuring voltage from battery negative post to engine block with the starter cranking — should be < 0.3V drop.
- Bad ground connection. Less common but the body-to-frame and battery-negative-to-frame grounds corrode. Inspect both.
Diagnostic Approach
- Free first step: take the battery to AutoZone / O’Reilly / Advance for a free load test. They’ll print a result. CCA below 75% of spec = replace battery.
- Check alternator output: at warm idle with the engine running, voltage at the battery should be 13.8-14.8V. Below 13.5V = charging system fault.
- Voltage-drop test on the negative cable: measure from battery negative post to engine block while cranking. Should be < 0.3V drop.
- For parasitic draw: connect a multimeter in series with the negative battery cable after the truck has sat for 20 minutes (modules go to sleep). Reading should be < 50 mA. Higher = something staying awake.
- Inspect battery terminals and cables for green corrosion. Clean and re-tighten.
Possible Fixes
| Fix | When |
|---|---|
| Replace battery | Battery > 4 years old or load test fails |
| Replace alternator | Charging voltage < 13.5V at warm idle |
| Clean and tighten cables / terminals | Visible corrosion or voltage drop > 0.3V |
| Trace and fix parasitic draw | Battery dies after 2-3 days of sitting |
Can I Still Drive With B1325?
Yes if the engine starts and runs, but expect cascading issues — many electronics misbehave below 12V. Address quickly because once the battery dies completely you’ll be stranded or need a jump start.
How Serious Is This Code?
Moderate. Not safety-critical immediately, but a failing battery / charging system inevitably leaves you stranded.
Repair Costs
| Repair | Cost |
|---|---|
| Battery replacement | $180 – $320 |
| Alternator replacement | $340 – $620 |
| Cable / terminal cleaning | $40 – $120 |
| Parasitic draw diagnosis | $120 – $240 (shop labor) |
FAQ
What is B1325 on a Chevy Silverado?
B1325 means the body control module detected low device voltage (below ~10.5V). The cause is usually a tired battery, a worn alternator, parasitic draw, or corroded cables. It’s frequently paired with C0561 (StabiliTrak disabled) and various U-codes because low voltage affects multiple modules.
How long does a Silverado battery last?
OE batteries typically last 4-6 years. In hot climates expect closer to 4 years; cold climates closer to 6. By year 5 most owners notice slower cranking on cold mornings. A free load test at any auto parts store will tell you for sure.
Can low battery voltage cause Check Engine Light on a Silverado?
Yes — many modules log faults when voltage drops below their operating threshold. You’ll see codes like B1325, C0561, U-communication codes, and sometimes random P-codes appear together when the battery is tired. Replace the battery and many of those clear on their own.
How do I find a parasitic draw on my Silverado?
Disconnect the negative cable, put a multimeter in series (DC amps mode) between the cable and the post, and wait 20 minutes for the modules to sleep. Normal reading should be < 50 mA. If higher, pull fuses one at a time until the draw drops — the fuse you pulled identifies the offending circuit.