Throttle Position Sensor
2018 Honda Accord · 1.5L I4 Turbo
Sensor Type
piezoresistive
Waveform Type
dc-variable
Location
Integrated into electronic throttle body assembly on intake manifold, right side of engine
Pins
6-pin connector
Timebase
500ms/div
Voltage Scale
1V/div
Trigger
Free run or 2V
Wiring
Two sensors: TPS1 - Pink (5V ref), Green/White (signal), Black (ground); TPS2 - Pink (5V ref), Yellow/Green (signal), Black (ground)
Expected Voltage Range
At Idle
0.45V to 0.75V
At Higher RPM
4.2V to 4.6V
Expected Pattern
Two redundant linear voltage signals: TPS1 increases 0.5V to 4.5V with throttle opening, TPS2 inversely decreases 4.5V to 0.5V creating mirror image
Known-Good Waveform
Two smooth, linear voltage ramps that move in opposite directions as throttle opens. At idle (closed throttle), TPS1 reads 0.5-0.7V while TPS2 reads 4.3-4.5V. At wide open throttle, TPS1 reaches 4.3-4.5V and TPS2 drops to 0.5-0.7V. Both signals should be clean without noise, glitches, or flat spots and maintain inverse relationship with combined voltage near 5V at all positions.
Common Failure Patterns
One sensor signal stuck at fixed voltage or shows erratic jumps, other sensor normal
Cause: Failed potentiometer track in one of the redundant sensors, carbon buildup on contacts
Both signals present but correlation error, voltages don't sum to ~5V
Cause: Throttle body assembly internal fault, requires replacement of entire unit as sensors not serviceable
Diagnostic Tips
Honda uses drive-by-wire with non-serviceable integrated TPS - entire throttle body must be replaced if sensors fail. Perform throttle body relearn procedure after battery disconnect or throttle cleaning using HDS scan tool. Check for carbon buildup causing mechanical binding which can damage position sensors.
Related Diagnostic Trouble Codes
P0120P0121P0122P0123P0124
Always confirm waveform data with your vehicle's OEM service manual before diagnosing.
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