Throttle Position Sensor
2017 Toyota Corolla · 1.8L I4
Sensor Type
hall-effect
Waveform Type
dc-variable
Location
Integrated into electronic throttle body on intake manifold, passenger side of engine, non-serviceable component of throttle body assembly
Pins
6-pin connector
Timebase
500ms/div for sweep test
Voltage Scale
1V/div
Trigger
Not applicable for DC signal
Wiring
Dual redundant sensors: VTA1 (Yellow), VTA2 (Blue), VC1 5V reference (Red/White), VC2 5V reference (Red/Black), E2 ground (Brown), motor control circuits
Expected Voltage Range
At Idle
0.5V to 0.9V
At Higher RPM
3.8V to 4.7V
Expected Pattern
Two independent linear voltage signals that change proportionally with throttle angle, VTA1 increases from 0.5V to 4.5V, VTA2 increases from 2.0V to 4.0V at different rate for redundancy
Known-Good Waveform
VTA1 signal should show smooth linear increase from approximately 0.6-0.8V at closed throttle to 4.2-4.6V at wide open throttle. VTA2 operates inversely or at different slope for redundancy, typically 2.0-2.2V at closed throttle. Both signals must track smoothly without steps, dropouts, or noise, and maintain proper voltage relationship to each other for ECM rationality checks.
Common Failure Patterns
One sensor signal becomes erratic, shows steps or flat spots during smooth throttle sweep
Cause: Carbon buildup on throttle plate causing mechanical binding or internal potentiometer track wear in sensor element
Both signals present but fail rationality check, voltage relationship incorrect
Cause: One sensor circuit shifted out of range due to 5V reference voltage problem or internal sensor circuit failure
Related DTCs: P2135
Diagnostic Tips
The 2ZR-FE engine throttle body requires periodic cleaning per TSB 0087-11. Perform throttle body relearn procedure using Toyota Techstream after cleaning or battery disconnect. Do not replace TPS individually as it's part of complete throttle body assembly.
Related Diagnostic Trouble Codes
P0120P0121P0122P0123P0124
Always confirm waveform data with your vehicle's OEM service manual before diagnosing.
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