Power Supply Voltage Too Low
2002-2004 Audi A6 3.0L V6
Description
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.
Related Codes
Other Powertrain Codes
- P0001Fuel Volume Regulator Control Circuit/Open
- P0002Fuel Volume Regulator Control Circuit Range/Performance
- P0003Fuel Volume Regulator Control Circuit Low
- P0004Fuel Volume Regulator Control Circuit High
- P0010Intake Camshaft Position Actuator Circuit/Open Bank 1
- P0011Intake Camshaft Position Timing Over-Advanced Bank 1
- P0012Intake Camshaft Position Timing Over-Retarded Bank 1
- P0013Exhaust Camshaft Position Actuator Circuit/Open Bank 1
- P0014Exhaust Camshaft Position Timing Over-Advanced Bank 1
- P0015Exhaust Camshaft Position Timing Over-Retarded Bank 1
P1602 on Other Vehicles
Common Questions
What does code P1602 mean on a 2002-2004 Audi A6?
P1602 stands for "Power Supply Voltage Too Low". 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.
What are the symptoms of P1602 on a Audi A6?
Common symptoms of P1602 include: Check Engine Light, Multiple fault codes stored, Engine running rough, Starting difficulties, Electrical accessories dimming.
What causes P1602 on a 2002-2004 Audi A6?
Common causes of P1602 include: Weak or failing battery, Faulty alternator or voltage regulator, Corroded battery terminals, High-resistance connection in power supply, Parasitic drain depleting battery.