The ECU detected that Motor #1's input signal wire is shorted directly to ground, like a broken electrical connection that's touching metal instead of completing its proper circuit. This prevents the sensor from sending valid data to the engine computer.
The ECU monitors the voltage signal from Motor #1's input circuit, expecting it to fluctuate within normal operating range. When the circuit shorts to ground, the signal voltage drops to zero or near-zero, triggering a fault condition that indicates an electrical short rather than a sensor malfunction.
| Parameter | Normal Range | Fault Condition |
|---|---|---|
| Input Signal Voltage | 0.5V to 4.5V (varies by sensor type) | Below 0.1V or shorted to ground |
| Circuit Resistance | Expected ohm range per manufacturer specs | Abnormally low resistance indicating short path |