Crankshaft Position Sensor
2017 Toyota Corolla · 1.8L I4
Sensor Type
variable-reluctance
Waveform Type
ac-sine
Location
Mounted on the engine block below the exhaust manifold, facing the crankshaft timing gear at approximately 2 o'clock position when viewed from front of engine
Pins
2-pin connector
Idle Frequency
50 Hz
Timebase
20ms/div at idle, 5ms/div for pattern verification
Voltage Scale
5V/div
Trigger
0V, rising edge
Wiring
Gray wire (signal +) and Black wire (signal -/ground), wrapped in protective shielding due to high heat location
Expected Voltage Range
At Idle
-2.5V to 2.5V
At Higher RPM
-12V to 12V
Expected Pattern
34 teeth with 2 missing teeth (34-2 pattern) per crankshaft revolution, creating 34 AC pulses with one large gap where missing teeth create extended period between pulses
Known-Good Waveform
Clean sinusoidal AC waveform with consistent amplitude showing 34 evenly-spaced pulses followed by a gap approximately twice the normal tooth spacing (missing tooth gap). Voltage amplitude increases proportionally with RPM. At idle (700-800 RPM), expect 2-5V peak-to-peak, increasing to 8-15V peak-to-peak at 3000+ RPM.
Common Failure Patterns
Erratic amplitude with some pulses significantly weaker or intermittent dropout of signal, especially when engine is hot
Cause: Sensor coil winding breakdown due to excessive heat exposure from exhaust manifold proximity, common failure on high-mileage vehicles
Low amplitude waveform (less than 1V at idle) with otherwise normal shape
Cause: Excessive air gap between sensor tip and reluctor wheel, often due to sensor backing out or debris buildup on sensor tip
Related DTCs: P0335
Diagnostic Tips
This sensor frequently fails due to heat from the exhaust manifold on the 2ZR-FE engine. Always check for oil leaks from valve cover that can contaminate the reluctor wheel. Verify air gap is 0.5-1.4mm using feeler gauge.
Related Diagnostic Trouble Codes
P0335P0336P0337P0338P0339
Always confirm waveform data with your vehicle's OEM service manual before diagnosing.
Free, no signup. View all waveforms for this vehicle