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Severity: Moderate Code type: Manufacturer-specific (Toyota)

Toyota P1346 Code Meaning

Toyota's ECM sees the intake cam signal in the wrong place relative to the crankshaft signal.

At a glance

Severity: 3/5 – Moderate3/5

Severity: Moderate

Meaning
VVT (Cam Position) Sensor Range/Performance (Bank 1)
System
Ignition & Misfire · Powertrain
Safe to drive?
With caution
Typical repair cost
$90–$1,900
DIY difficulty
Hard

On Toyota VVT-i engines the camshaft position sensor is called the VVT sensor, because the ECM uses it both to identify cylinder 1 and to measure how far the intake cam has been advanced. The ECM constantly compares where the VVT sensor pulse arrives relative to the crankshaft sensor teeth; when that relationship drifts outside the allowed window on two consecutive trips, it stores P1346. The signal itself is present, so this is not a wiring fault like P0340 but a correlation problem. Toyota's own diagnostic chart for engines such as the 1NZ-FE, 1ZZ-FE, 3ZZ-FE and 2AZ-FE checks only two things, mechanical valve timing and then the ECM, which tells you where the factory expects the fault to be: a stretched or jumped timing chain, or a belt installed a tooth off on belt-driven V6 engines.

Can I keep driving? If the code appeared right after timing belt or chain work, or the engine rattles, don't drive it until the timing has been checked. Otherwise short trips are possible, though idle may be rough and power reduced.

How to read P1346

How to read P1346P11233464
  1. P Powertrain
  2. 1 Manufacturer-specific
  3. 3 Ignition / misfire
  4. 46 Specific fault

Symptoms

  • Check engine light on after two drive cycles
  • Rough or hunting idle, sometimes with stalling
  • Weak low-end power and sluggish throttle response
  • Chain rattle for a few seconds after a cold start on high-mileage chain engines
  • Code appearing immediately after a timing belt, water pump or head job
  • Fuel economy dropping a few mpg

Possible causes

Ranked by how often each cause is behind this code (editorial estimate).

  1. Timing chain stretched or tensioner/guides worn, letting the intake cam lag the crank 30%
  2. Timing belt or chain installed one tooth off, or jumped a tooth 20%
  3. OCV sticking or VVT-i controller not returning to its fully retarded lock position at idle 18%
  4. VVT sensor loose, contaminated with metal debris or failing 12%
  5. Crankshaft sensor signal plate damaged, or loose crank pulley on belt-driven engines 10%
  6. Low or badly degraded engine oil affecting the VVT-i rest position 6%
  7. ECM fault 4%

Diagnosis step by step

Diagnostic flow: P13461Gather history and related codes2Watch the VVT data at warm idle3Check oil level and listen on coldstart4Verify mechanical timing5Inspect both position sensors6Confirm the fix over two trips

  1. Gather history and related codes

    Ask what work was done recently and check whether P1349, P1656, P0335 or P0340 are stored too. P1346 alone right after timing work almost always means timing marks; P1346 with P1349 points more toward the VVT-i hardware.

    Tools: OBD-II scanner

  2. Watch the VVT data at warm idle

    With a Toyota-capable scan tool, read the actual cam advance (VVT change angle) and the OCV duty at hot idle. The actual advance should sit close to zero degrees at idle; a cam that stays advanced with low OCV duty suggests a sticking OCV or controller rather than a timing error.

    Tools: OBD-II scanner

  3. Check oil level and listen on cold start

    Confirm the oil is full and clean. Then listen at a cold start: a clattering timing cover that quiets after a few seconds is typical of a worn chain tensioner and stretched chain.

    Tools: Flashlight

  4. Verify mechanical timing

    Turn the engine to cylinder 1 TDC with the crank pulley notch on zero and check that the cam sprocket marks line up as the manual describes. One tooth off is enough for P1346; on a stretched chain the marks look slightly retarded on the intake side.

    Tools: Torque wrench, Flashlight

  5. Inspect both position sensors

    Remove the VVT sensor and look for metal fuzz on its tip or a damaged O-ring, and check it is fully seated. Pickup-coil versions typically measure several hundred to about 1,600 ohms depending on temperature; compare with the manual, and inspect the crank signal plate for damaged teeth.

    Tools: Multimeter, Screwdriver

  6. Confirm the fix over two trips

    After correcting timing or replacing parts, clear the code and drive two separate warm-up cycles. Because P1346 uses two-trip logic, one clean drive is not enough to call it fixed.

    Tools: OBD-II scanner

Where the parts are

Ignition: coils and spark plugs per cylinder – P13461234567
Ignition: coils and spark plugs per cylinder
  1. 1Ignition coil
  2. 2Spark plug
  3. 3Fuel injector
  4. 4Camshaft sensor
  5. 5Crankshaft sensor
  6. 6Engine computer (ECM)
  7. 7Intake manifold

Repair options & costs

RepairDIY?Estimated cost
Replace timing chain, tensioner and guides (four-cylinder) No $900–$1,900
Re-time a belt installed one tooth off (V6) No $300–$700
Replace oil control valve (OCV) Yes $150–$380
Replace VVT (camshaft position) sensor Yes $90–$260
Replace VVT-i controller (intake cam gear) No $500–$1,200

Rough US estimates for parts and labor; shop rates vary by region. Not a quote.

Notes by brand

Toyota

Early 1ZZ-FE engines are known for high oil consumption; running them low on oil speeds up chain and tensioner wear, a common background to P1346 on older Corollas and Celicas.

Emissions / smog test impact

Will fail

P1346 keeps the check engine light on, so the car fails an OBD smog check. Because it is a two-trip code, allow at least two warm-up drives after the repair before testing.

Frequently asked questions

Will a new camshaft sensor fix P1346?

Sometimes, but usually not. The sensor signal is present; the ECM just sees it in the wrong place, which is far more often timing or VVT hardware. A circuit fault in the sensor would normally set P0340 instead.

The code appeared right after a timing belt job. What happened?

Most likely the belt was installed a tooth off, or a cam moved while the belt was off. Recheck all timing marks before driving further.

Is P1346 the same as P0016?

They describe the same kind of crank-to-cam correlation fault. Toyota used P1346 on VVT-i engines of this era; newer Toyotas report it with the generic P0016.

Can a sticking oil control valve set P1346?

Yes. If the OCV leaks oil to the advance side at idle, the cam never returns to its resting position and the ECM sees the signal offset. That is why the scan data check comes before any timing teardown.

Sources