P1512low severityPowertrain
VTCS Fault
on 2003 Mazda MX-5 Miata 1.8L I4 · RWD
What this code means
The PCM has detected a fault in the Variable Tumble Control System. The VTCS controls intake air tumble by opening and closing runner valves to improve combustion efficiency at various engine speeds.
Symptoms
- Check Engine Light
- Slight loss of performance at certain RPMs
- Minor fuel economy reduction
Common causes
- VTCS solenoid valve failure
- VTCS actuator stuck from carbon
- Wiring issue in VTCS circuit
- VTCS vacuum supply leak
- Connector corrosion
Diagnostic steps
- Test VTCS solenoid resistance
- Command VTCS with scan tool and verify actuator movement
- Inspect VTCS actuator for carbon binding
- Check vacuum supply to VTCS
- Inspect wiring and connector
Repair notes
Replace the VTCS solenoid or clean the VTCS actuator if stuck from carbon.
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