Code
P1346
LEXUS
P — Powertrain
VVT Sensor Range Performance Problem Bank 1
Views:
UK: 24
EN: 53
RU: 31
AI status
Completed
Completed
100%
Causes
- Faulty VVT (camshaft angle/position) sensor or camshaft position sensor
- Open/short or poor connection in sensor harness or connector
- Sticking or failed VVT actuator (oil control valve/solenoid)
- Low engine oil level, dirty oil, or low oil pressure affecting VVT operation
- Incorrect cam timing (belt/chain jump or wear) or internal engine timing problem
- Faulty PCM or intermittent module fault
Symptoms
- Check Engine Light (MIL) illuminated with P1346 stored
- Poor idle, rough running or misfire at certain speeds/load
- Reduced engine power or limp-home mode in some cases
- Hard starting or no-start if correlation lost completely
- Odd engine noises if timing chain has jumped
What to check
- Read and record freeze-frame and all stored codes (check for related cam/crank or VVT codes)
- Inspect wiring and connector to Bank 1 camshaft/VVT sensor and to VVT solenoid for damage, corrosion, or looseness
- Check engine oil level and condition; review service history for extended oil-change intervals
- Visually inspect timing components if accessible (timing chain/belt, tensioner)
- Scan live data: camshaft angle/position, commanded VVT duty, actual camshaft target vs actual, and crankshaft position correlation
- Use a scope (or high-quality multimeter) to verify sensor waveform and VVT solenoid PWM signal
Signal parameters
- Camshaft position sensor: pulsed/square or variable voltage signal typically 0.2–4.8 V (depends on sensor type); waveform frequency proportional to engine speed
- Crank vs cam correlation: cam angle should follow PCM target and remain within manufacturer-specified degrees of crank reference
- VVT actuator/solenoid control: PWM duty from 0–100% (varies by command) at a control frequency (often ~100–300 Hz); actual actuator feedback should change cam angle accordingly
- Resistance: reference manufacturer spec for sensor resistance; continuity OK, no short to power or ground
Diagnostic algorithm
- Connect a professional scan tool and save DTCs and freeze-frame data. Note any additional related codes (cam/crank/VVT).
- Perform a visual inspection: battery connections, engine grounds, sensor and solenoid connectors, wiring harness routing and chafing. Repair obvious damage.
- Check engine oil level and condition; top up or change oil if contaminated, very old, or too low. Use manufacturer-recommended oil grade.
- Using live data, compare commanded VVT target angle vs actual camshaft angle. If commanded changes but actual does not, suspect VVT actuator/solenoid or oil supply.
- Backprobe the VVT sensor connector or use an oscilloscope to verify proper signal waveform and voltage. Replace sensor if signal missing or erratic outside expected pattern.
- Test VVT solenoid: with key on/engine off command PWM with scan tool and verify solenoid response (audible click) and that PWM changes. Check solenoid resistance and supply voltage. Replace solenoid if inoperative or stuck.
- Check wiring: verify continuity and no shorts from sensor/solenoid to power/ground. Repair any open/short. Clean and secure connectors.
- If wiring, sensor, and solenoid are good but timing correlation is wrong, perform mechanical timing inspection: check timing chain/belt alignment, tensioner, guide wear and cam sprocket condition. Repair as needed.
- After repairs, clear codes, perform an initial idle and road test and re-check live data. Perform any manufacturer required cam/crank relearn or VVT adaptation procedures.
- If faults persist and all above checks are good, consider module/ECM testing or replacement as last resort, following manufacturer procedures.
Likely causes
- Damaged or corroded connector at Bank 1 camshaft position/VVT sensor
- VVT solenoid stuck closed or clogged with varnish/sludge
- Low oil level or severely degraded oil preventing VVT movement
- Broken/displaced timing chain/belt or jumped sprocket causing cam/crank correlation error
- Intermittent wiring short to voltage or ground for the sensor circuit
- Failed camshaft position sensor reproducing erratic voltage or no signal
Fault status
Status
Bank 1 VVT/camshaft position sensor signal is outside the expected range or not following commanded timing. Check sensor, wiring, VVT actuator, oil condition/pressure, and mechanical timing.
Repair difficulty: Medium
Diagnostic time: 1.0-3.0 hours
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