Circuit Description
The Accelerator Pedal Position (APP) module provides a voltage signal that changes relative to the accelerator pedal position. There are three sensors which are located within the APP module that are scaled differently. This is a type D DTC.
Conditions for Setting the DTC
| • | The voltage is greater than 4.75 volts on the APP 2. |
| • | The condition was met for 2 seconds. |
Action Taken When the DTC Sets
| • | The input from the APP 2 sensor is ignored. |
| • | This DTC will not turn the Service Throttle Soon lamp ON by itself. |
| • | The throttle will operate normally as long as there is only one sensor malfunction present. If two different APP sensors have a malfunction, the Service Throttle Soon lamp will light and the PCM will limit the power. If three APP sensors have a malfunction present, the Service Throttle Soon lamp will light and the PCM will only allow the engine to operate at idle. |
Conditions for Clearing the MIL/DTC
| • | A History DTC will clear after forty consecutive warm-up cycles during which the diagnostic does not fail (coolant temperature has risen 5°C (40°F) from the start up coolant temperature and the engine coolant temperature exceeds 71°C (160°F) during that same ignition cycle. |
| • | Use of a Scan tool will clear the DTC codes. |
Diagnostic Aids
There are no driveability issues associated with the APP module unless a DTC is present. The most likely cause of this DTC are poor connections or the sensor itself. The least likely is a PCM problem.
A scan tool reads the APP 2 position in volts and should read about 4.5 volts with the throttle closed and the ignition ON or at idle. The voltage should decrease at a steady rate as the throttle is moved toward WOT. Also, 90% pedal travel is acceptable for a correct APP operation. Scan the APP 2 signal while depressing the accelerator pedal with the engine stopped and the ignition ON. The display should vary from about 4.5 volts when the throttle is closed to about 1.5 volts when the throttle is held at a Wide Open Throttle (WOT) position. A P1125 may possibly set along with a P0223 if the signal circuit is open.
Test Description
The number(s) below refer to the Step number(s) on the Diagnostic Table.
-
This Step determines if PO223 is a hard failure or an intermittent condition.
-
This Step will check for an open in the ground circuit.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 |
Important: Before clearing the DTCs, use the scan tool Capture Info in order to record the Freeze Frame and the failure records for reference, as the data will be lost when the Clear Info function is used. Was the Powertrain On-Board Diagnostic (OBD) System Check performed? | -- | ||
Is the APP 2 greater than or equal to the specified value? | 4.75V | |||
3 | The DTC is intermittent. If no additional DTCs are stored, refer to Diagnostic Aids. If any additional DTCs were stored, refer to the applicable DTC table(s) first. Are there any additional DTCs stored? | -- | Go to the Applicable DTC Table | Go to Diagnostic Aids |
4 |
Is the test light ON? | -- | ||
Use a fused jumper wire in order to jump the APP 2 signal circuit to the APP 2 ground circuit at the APP harness connector. Does the scan tool display the APP 2 voltage less than the specified value. | 0.25V | |||
6 |
Was the APP 2 sensor signal circuit open? | -- | ||
7 |
Was the APP 2 sensor ground circuit open? | -- | ||
8 | Check for a poor electrical connection at the APP sensor. Was the repair performed? | -- | ||
9 | Replace the APP module. Refer to APP Module Replacement . Is the action complete? | -- | -- | |
10 | Replace the PCM. Important: If the PCM is malfunctioning, the new PCM must be programmed. Refer to Powertrain Control Module Replacement/Programming . Is the action complete? | -- | -- | |
11 |
Does the Scan Tool indicate that this diagnostic Ran and Passed? | -- | ||
12 | Use the Scan Tool in order to select Capture Info, Review Info. Are there any DTCs displayed that have not been diagnosed? | -- | Go to the Applicable DTC Table | System OK |
