P1631high severityPowertrain
Generator Output Voltage No Output
on 1998 Mazda B2500 2.5L I4 · FWD
What this code means
The PCM has detected that the generator (alternator) is producing no output voltage. The charging system is not maintaining battery charge, and the vehicle is running solely on battery power.
Symptoms
- Check Engine Light
- Battery warning light on
- Battery draining
- Electrical systems losing power
- Vehicle will eventually stall
Common causes
- Failed alternator (diode pack or rotor)
- Broken or slipping serpentine belt
- Disconnected alternator wiring
- Blown alternator fuse or fusible link
- Faulty voltage regulator
Diagnostic steps
- Measure charging voltage at battery with engine running (should be 13.5-14.8V)
- Inspect serpentine belt condition and tension
- Check alternator wiring connections
- Test alternator output with load tester
- Check alternator fuse and fusible links
Repair notes
Replace the alternator if it has no output; check belt and wiring first.
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