Network
generic or reserved
U3003
Battery Voltage
The control module detected battery voltage outside its acceptable operating window. Either too low (drained battery, weak charging) or too high (charging system overvoltage).
SystemNetwork
Typegeneric or reserved
GroupU3
Range / number– / 03
Possible causes
- Battery aged or sulfated high
- Alternator regulator fault (over- or undervoltage) medium
- Gateway module routing CAN messages incorrectly low
Symptoms
- Multiple warning lights may illuminate
- Affected modules may go into limp mode or shut down
- Specific functions inoperative depending on module
- Diagnostic tools may show communication faults
Inspection / repair
- Difficulty: easy
- DIY: possible
- Estimated cost: 80–600 €
- Estimated time: 0.3–2 h
- Component: battery
- Component: alternator
- Component: charging system
- MIL / check engine light
- drive cycle required
Sources
References
sae:J2012