P1633critical severityPowertrain
ECM Malfunction ETCS Circuit
on 1997 Lexus SC 300 3.0L I6 · RWD
What this code means
Internal ECM fault related to the Electronic Throttle Control System processor.
Symptoms
- CEL
- Limp mode
- Severely limited throttle
- Idle only
- Reduced power
Common causes
- Internal ECM ETCS failure
- Power supply issues
- ECM overheating
Diagnostic steps
- Check ECM voltage supply
- Monitor ETCS signals
- Test throttle body
- Check for overheating
Repair notes
Replace ECM.
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