Two independent ratiometric voltage signals (redundant sensors), TP1 increases with throttle opening, TP2 follows inverse relationship for fault detection
Known-Good Waveform
At idle (closed throttle), TP1 reads 0.5-1.0V while TP2 reads approximately 4.0-4.5V. As throttle opens to WOT, TP1 increases smoothly to 4.2-4.7V while TP2 decreases inversely to 0.5-1.0V. The two signals should maintain a sum of approximately 5V throughout the sweep with smooth, linear transitions and no steps or flat spots. Response time should be instantaneous with throttle blade movement.
Common Failure Patterns
One sensor signal stuck at fixed voltage or reads implausibly while other sensor operates normally
Cause: Partial sensor failure in redundant TPS circuit, carbon buildup on throttle blade causing mechanical binding
Ford electronic throttle bodies on EcoBoost engines are prone to carbon buildup affecting both sensor readings and blade movement; clean throttle body and perform relearn procedure after any service. Always monitor both TP1 and TP2 simultaneously to verify proper correlation—voltage sum should remain constant at approximately 5V throughout entire throttle range.
Related Diagnostic Trouble Codes
P0120P0121P0122P0123P0124
Always confirm waveform data with your vehicle's OEM service manual before diagnosing.