P1602high severityPowertrain
Power Supply Voltage Too Low
on 2020 Porsche Taycan Electric · AWD
What this code means
The ECU detected that its supply voltage has dropped below the minimum operating threshold. Low voltage can cause erratic ECU behavior, false fault codes, and poor engine performance.
Symptoms
- Check Engine Light
- Multiple fault codes stored
- Engine running rough
- Starting difficulties
- Electrical accessories dimming
Common causes
- Weak or failing battery
- Faulty alternator or voltage regulator
- Corroded battery terminals
- High-resistance connection in power supply
- Parasitic drain depleting battery
Diagnostic steps
- Test battery voltage and load test
- Test alternator output voltage and current
- Inspect battery terminals and connections
- Check main power supply wiring to ECU
- Test for parasitic electrical drain
Repair notes
Replace the battery or alternator; clean and tighten all power supply connections.
🔌 Don't have a code reader?
Any of these will read and clear this code — pick by how deep you want to go.
Bluetooth code reader (~$25)
Veepeak OBDCheck BLE →
Pairs with your phone — reads and clears codes, live data.
Serious DIY (~$100)
BlueDriver Pro →
Enhanced codes (ABS, airbag, TPMS) plus repair reports.
Shop-grade tablet (~$300+)
Autel MaxiCOM MK808S →
Bidirectional tests, service resets, all systems.
As an Amazon Associate, OLP earns from qualifying purchases — how we link. This never changes the specs we publish.
Other Powertrain codes on this vehicle
P0070
Ambient Air Temperature Sensor Circuit
P0071
Ambient Air Temperature Sensor Range/Performance
P0072
Ambient Air Temperature Sensor Circuit Low
P0073
Ambient Air Temperature Sensor Circuit High
P0115
Engine Coolant Temperature (ECT) Sensor 1 Circuit
P0116
ECT Sensor 1 Circuit Range/Performance
P0117
ECT Sensor 1 Circuit Low Input
P0118
ECT Sensor 1 Circuit High Input
P0119
ECT Sensor 1 Circuit Intermittent
P0125
Insufficient Coolant Temperature for Closed Loop Fuel Control