EV or hybrid warning
or reduced power?
A hybrid or EV that throws a warning, drops into reduced-power / limp mode, or won’t charge usually has a fault in the high-voltage battery, inverter, charging system, or a control module that most shops won’t touch. Spot-On diagnoses hybrid and EV high-voltage systems with OEM tooling at our San Antonio shop — work many general shops decline.
Common causes.
- High-voltage battery faultA weak cell/module or an isolation fault trips warnings and forces the car into reduced power.
- Inverter or converter faultFaults in the power electronics cut drive power or shut the system down.
- Charging system faultAn onboard-charger or charge-port problem prevents the vehicle from charging.
- Control-module or sensor faultA failed module or HV sensor sets high-voltage codes and limits operation.
Diagnosed properly, fixed at the root.
High-voltage systems are genuinely dangerous and require trained handling and OEM tools — this is exactly the work most general shops turn away. Misdiagnosis is expensive: the goal is to pinpoint the failed component before you replace a costly battery pack you may not need.
- HV-safe diagnosis. De-energize and verify the high-voltage system is safe before any testing.
- Battery / cell analysis. Test the pack down to the module/cell level to find weakness or isolation faults.
- Inverter & charger testing. Check the power electronics and charging system for faults.
- Pinpoint & report. Isolate the failed component so you replace only what’s actually bad.
Questions we get about this.
In-shop, by appointment
Drop-off at 4715 N Stahl Park, Suite 105, San Antonio. We do not dispatch mobile service to retail customers.
Book an appointment →Mobile, remote, or mail-in
Mobile dispatch across the San Antonio metro. J2534 remote programming + mail-in bench service nationwide.
See trade services →Let’s get it diagnosed right.
Call with the year, model, and what the vehicle is doing. Bring it in actively faulting if you can — most diagnoses are same-day.