P1121 CHEVROLET - Throttle Position Sensor Circuit Intermittent High Voltage
When is the code detected?When the Powertrain Control Module (PCM) senses a signal voltage higher than the normal operating range of the sensor, the P1121 will set.
P1121 Chevrolet DescriptionThe Throttle Position (TP) sensor is a potentiometer. The TP sensor provides a voltage signal that changes relative to throttle blade angle. This signal voltage is one of the most important inputs used by the Powertrain Control Module (PCM). The TP sensor has a 5.0 volt reference, a ground and a signal circuit.
TP sensor Signal voltage should be about 0.6 volt at idle. The TP sensor voltage should increase to above 4.0 volts at wide open throttle (WOT).