C0800
Drive System Voltage Low
The chassis control module has detected that the supply voltage is below the operating threshold required for ABS, ESP or steering systems. Many chassis functions are limited or disabled until the voltage returns to a normal range.
- Check engine light: Not always
- Emissions related: No
- Repair difficulty: medium
Symptoms
- ABS warning light on
- ESC/stability control deactivated
- Possible reduced brake assist
- Speedometer may behave erratically
Common causes
Ordered by how often each turns out to be the cause.
- Battery weak or dischargedCommon
- Alternator output faultPossible
- High-resistance ground or supply connectionLess likely
Parts involved
- Battery
- Alternator
- Power Supply Wiring
- Chassis Control Module
C0800 is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.