P1633low severityPowertrain
KAM Voltage Too Low
on 2009 Mazda MX-5 Miata 2.0L I4 · RWD
What this code means
The PCM has detected that the Keep Alive Memory voltage is too low to maintain stored data. The PCM will lose adaptive values and must relearn when power is restored.
Symptoms
- Check Engine Light
- Loss of adaptive fuel trim values
- Rough idle after restart
- Transmission relearning shift points
Common causes
- Discharged battery
- Corroded battery cables
- Excessive parasitic drain
- Blown KAM fuse
- Faulty PCM power relay
Diagnostic steps
- Test battery voltage with key off (should be above 12.4V)
- Inspect battery terminals for corrosion
- Check KAM fuse
- Test for parasitic drain
- Check PCM power relay
Repair notes
Clean battery terminals; replace the battery if discharged; repair the KAM power circuit.
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