P2127-ACCELERATOR PEDAL POSITION SENSOR 2 CIRCUIT LOW
For a complete wiring diagram, refer to the Wiring Information.
Theory of Operation
The Electronic
Throttle Control (ETC) system uses two Accelerator Pedal Position
(APP) Sensors to monitor the accelerator pedal position. The APP Sensors
1 and 2 are integrated into one assembly located at the pedal assembly.
Each sensor has a 5-volt reference circuit, a low reference circuit,
and a signal circuit. The Powertrain Control Module (PCM) reads the
two signals individually and then compares the two signals as a redundant
check of the throttle position. One of the sensors will fluctuate
between 0 volts and 5.0 volts and the other sensor will fluctuate
between 0 volts and 2.5 volts. The fluctuation of the two sensors
should move proportionately. E.G. When operating properly, the voltage
reading of the sensor operating on the 5.0 volt scale will always
approximately two time the voltage reading of the sensor on the 2.5
volts scale.
When Monitored:
With the ignition on.
Set Condition:
The APP Sensor 2 Signal circuit is below 0.097 volts for 0.3 seconds.
4.
CHECK THE (K29) APP SENSOR 2 SIGNAL CIRCUIT FOR A SHORT TO THE SENSOR GROUND CIRCUITS
1.
Measure the resistance between the (K29) APP Sensor 2 Signal circuit and the (K400) APP Sensor No.2 Sensor Ground circuit at the APP Sensor harness connector.
2.
Measure the resistance between the (K29) APP Sensor 2 Signal circuit and the (K167) APP Sensor 1 Sensor Ground circuit at the APP Sensor harness connector.
Is the resistance above 10k Ohms for both measurements?
Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Accelerator Pedal Position Sensor and the Powertrain Control Module (PCM).
2.
Look for any chafed, pierced, pinched, or partially broken wires.
3.
Look for broken, bent, pushed out or corroded terminals.
4.
Perform any Technical Service Bulletins that may apply.
