Chevrolet-specific code — factory diagnostic data| DTC Data Sheet | |
| Code | B1325 |
| Vehicle | Chevrolet Tahoe / Suburban (2007-2020) |
| Engine | All |
| System | CHARGING SYSTEM |
| Fault type | Circuit |
| Official meaning | Device Power Voltage Low |
Definition source: Chevrolet factory description. Diagnostic guidance is based on factory-defined fault logic for this code.
Decode any Chevrolet Tahoe VIN — free recalls, specs & safety ratings — free VIN decoder with NHTSA data
B1325 Quick Answer
B1325 on a Tahoe is set by the body control module when supply voltage drops below ~10.5V. Same root-cause pattern as the Silverado: aging battery (most common, 4-6 years), worn alternator, parasitic draw, or corroded cables. Tahoes with rear-seat entertainment systems or aftermarket accessories see parasitic-draw issues more often than work trucks.
What Does B1325 Mean on a Chevy Tahoe?
The Chevrolet Tahoe (2007-2020) shares the GMT900 / K2XX SUV platform with the Suburban — and the engine families with the Silverado 1500 pickup. B1325 root causes mirror the truck-line behavior on the same engines. The model-specific failure patterns documented below apply to both the Tahoe and Suburban variants.
Symptoms
- Slow cranking
- Multiple dash warnings (ABS, StabiliTrak, BCM)
- Codes like B1325, C0561, U-codes set together
- Interior lights dim with accessories
- Battery dies overnight or after a few days of sitting
Common Causes (Most Likely on This Model First)
- Failing battery. OE Tahoe batteries last 4-6 years. Year 5+ in hot climates: load test shows CCA below 75% of spec.
- Failing alternator. Output below 13.5V at warm idle with accessories on.
- Parasitic draw (more common on Tahoes than work trucks). Rear DVD systems, aftermarket alarms, faulty BCM keeping modules awake.
- Corroded battery cables. Negative terminal especially. Voltage drop test > 0.3V cranking = repair.
- Aftermarket accessory wired ahead of the BCM sleep cycle. Common on Tahoes with installed remote starters, dash cams, or backup cameras.
Diagnostic Approach
- Free battery load test at AutoZone / O’Reilly / Advance — replace if CCA below 75% of spec.
- Alternator output at warm idle should be 13.8-14.8V. Below 13.5V = charging fault.
- Voltage-drop on negative cable while cranking should be < 0.3V.
- Parasitic draw test: multimeter in series with negative cable after 20 minutes of sitting — should be < 50 mA.
- Inspect aftermarket accessories — common parasitic-draw sources on Tahoes.
Possible Fixes
| Fix | When |
|---|---|
| Replace battery | Battery > 4 years old or load test fails |
| Replace alternator | Charging voltage < 13.5V at warm idle |
| Repair parasitic draw | Battery dies in 2-3 days of sitting |
| Clean / tighten cables | Visible corrosion, voltage drop > 0.3V |
Can I Still Drive With B1325?
Yes if the engine starts, but expect cascading electronic issues below 12V. Address quickly — a dead battery leaves you stranded.
How Serious Is This Code?
Moderate. Not safety-critical immediately, but failing charging systems inevitably strand the vehicle.
Repair Costs
| Repair | Cost |
|---|---|
| Battery replacement | $180 – $320 |
| Alternator replacement | $340 – $620 |
| Parasitic draw diagnosis | $120 – $240 |
FAQ
What causes B1325 on a Chevy Tahoe?
Most commonly an aging battery (4-6 year service life), then a worn alternator, parasitic draw from aftermarket accessories (rear entertainment, alarms, dash cams), or corroded battery cables. The fix is usually a $200 battery replacement.
How long should a Tahoe battery last?
4-6 years typically. Hot climates closer to 4; cold climates closer to 6. Free load tests at any auto parts store will tell you when it’s time.
Why does my Tahoe battery keep dying?
Three possibilities: (1) the battery itself is end-of-life (load test confirms), (2) the alternator isn’t fully charging it (output check at warm idle), or (3) a parasitic draw is discharging it over a few days (multimeter test on the negative cable). Tahoes with aftermarket accessories often have parasitic draws.
Will B1325 cause other warning lights on my Tahoe?
Yes — low voltage cascades. You’ll typically see C0561 (StabiliTrak), various U-communication codes, and sometimes random P-codes appear together. Fix the charging system; most of those clear on their own.