P2502high severityPowertrain
Charging System Voltage
on 2004 Mazda MX-5 Miata 1.8L I4 · RWD
What this code means
The system charging voltage is outside the expected regulation window.
Symptoms
- Battery light
- Check engine light
- Electrical accessories malfunction
- Battery drains overnight
Common causes
- Failed alternator
- Loose drive belt
- Battery terminal corrosion
- ECM-controlled charging fault
Diagnostic steps
- Check battery voltage engine off and running
- Inspect belt tension and condition
- Load test alternator
- Check battery terminals
Repair notes
Replace alternator or battery. Clean terminals. Check belt.
Other Powertrain codes on this vehicle
P0001
Fuel Volume Regulator Control Circuit/Open
P0002
Fuel Volume Regulator Control Circuit Range/Performance
P0003
Fuel Volume Regulator Control Circuit Low
P0004
Fuel Volume Regulator Control Circuit High
P0010
Intake Camshaft Position Actuator Circuit/Open Bank 1
P0011
Intake Camshaft Position Timing Over-Advanced Bank 1
P0012
Intake Camshaft Position Timing Over-Retarded Bank 1
P0013
Exhaust Camshaft Position Actuator Circuit/Open Bank 1
P0014
Exhaust Camshaft Position Timing Over-Advanced Bank 1
P0015
Exhaust Camshaft Position Timing Over-Retarded Bank 1