P0391moderate severityPowertrain
Camshaft Position Sensor B Circuit Range/Performance (Bank 2)
on 2017 Toyota Corolla 1.8L I4 · FWD
What this code means
The Bank 2 camshaft position sensor B signal is out of the expected range or performance window. Timing correlation may be off, affecting drivability.
Symptoms
- Rough idle
- Reduced power
- Illuminated MIL
Common causes
- Faulty camshaft position sensor
- Damaged tone/reluctor wheel
- Wiring resistance or corrosion
- Cam timing out of correlation
Diagnostic steps
- Read freeze frame and correlation data
- Inspect tone wheel for damage
- Check wiring continuity and resistance
- Verify cam timing, replace sensor if needed
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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
P0005
Fuel Shutoff Valve A Control Circuit/Open
P0006
Fuel Shutoff Valve A Control Circuit Low
P0007
Fuel Shutoff Valve A Control Circuit High
P0008
Engine Position System Performance - Bank 1
P0009
Engine Position System Performance - Bank 2
P0010
Intake Camshaft Position Actuator Circuit/Open Bank 1