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Chrysler 300/300 Touring/300C, Dodge Magnum. Manual - part 1462
Possible Causes
APP SENSOR 1
APP SENSOR 2
Diagnostic Test
1.
APP SENSOR IDLE VOLTAGE
NOTE: If there are any Accelerator Pedal Position Sensor DTC’s active in the ECM, diagnose DTC’s before
continuing this test.
NOTE: The APP Sensor is a device that contains two separate potentiometer type sensors. Each sensor has
its own 5-volt supply circuit, sensor ground circuit and signal circuit. The APP Sensor no longer incorpo-
rates a low-idle switch.
NOTE: The APP Sensor 1 signal should always be double the voltage of the APP Sensor 2 signal.
NOTE: Ensure the accelerator pedal is free from any restriction or binding before continuing.
Turn the ignition on.
With the scan tool, read the APP Sensor 1 and APP Sensor 2 Volts with the accelerator pedal in the at rest position.
Does the scan tool display between 0.38 and 0.53 volt for sensor 1 and 0.19 and 0.27 volt for sensor
2?
Yes
>> Go To 2
No
>> Check the APP Sensor circuits for proper resistance. If o.k., replace the APP Sensor in accordance with
the Service Information.
Perform the ECM Verification Test Ver. 1. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)
2.
APP SENSOR 1
While back probing, measure the voltage of the APP Sensor 1 Signal circuit at the ECM.
Monitor the voltmeter while slowly pressing the accelerator pedal completely down.
NOTE: APP signals are displayed in voltage and percentage on the scan tool. Although APP 1 voltage is
double APP 2 voltage, the percentage display of APP 1 and APP 2 should be within 2.5% of each other
during all phases of accelerator pedal travel.
Did the voltage increase smoothly with pedal travel?
Yes
>> Go To 3
No
>> Replace the Accelerator Pedal Position Sensor in accordance with the Service Information.
Perform the ECM Verification Test Ver. 1. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)
3.
APP SENSOR 2
While back probing, measure the voltage of the APP Sensor 2 Signal circuit at the ECM.
Monitor the voltmeter while slowly pressing the accelerator pedal completely down.
NOTE: APP signals are displayed in voltage and percentage on the scan tool. Although APP 1 voltage is
double APP 2 voltage, the percentage display of APP 1 and APP 2 should be equal during all phases of
accelerator pedal travel.
Did the voltage increase smoothly with pedal travel?
Yes
>> Go To 4
No
>> Replace the Accelerator Pedal Position Sensor in accordance with the Service Information.
Perform the ECM Verification Test Ver. 1. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)
9 - 1872
ENGINE ELECTRICAL DIAGNOSTICS - DIESEL
LX