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.
Conditions for Setting the DTC
| • | The voltage is greater than 4.75 volts for 2 seconds on the APP 3 sensor. |
| • | The conditions were met for 2 seconds. |
Action Taken When the DTC Sets
| • | The Service Throttle Soon lamp will not illuminate when one APP DTC sets. The PCM will only illuminate the Service Throttle Soon lamp when multiple APP DTCs set. |
| • | The PCM records the operating conditions at the time the diagnostic fails. This information stores in the Failure Records. |
Conditions for Clearing the MIL/DTC
| • | A History DTC will clear after forty consecutive warm-up cycles during which the diagnostic does not fail (the 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 3 position in volts. The scan tool should read about 4.0 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 a Wide Open Throttle (WOT). Also, 90% pedal travel is acceptable for a correct APP operation. Scan the APP 3 sensor while depressing the accelerator pedal with the engine stopped and the ignition ON. The display should vary from about 4.0 volts when the throttle is closed to about 2.0 volts when the throttle is held at a Wide Open Throttle (WOT) position.
Test Description
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 any DTCs, use the Scan Tool Capture Info to save freeze frame and failure records for reference, as the Scan Tool loses data when using the Clear Info function. Was the Powertrain On-Board Diagnostic (OBD) System Check performed? | -- | ||
Is APP 3 greater than or equal to the specified value? | 4.75 V | |||
3 | The DTC is intermittent. If no additional DTCs are stored, refer to Diagnostic Aids. If additional DTCs were stored, refer to the applicable DTC table(s) first. Are 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 3 signal circuit to the APP 3 ground circuit at the APP harness connector. Does the Scan Tool display the APP 3 voltage less than the specified value. | 0.25 V | |||
6 |
Was the APP 3 sensor signal circuit open? | -- | ||
7 |
Was the APP 3 sensor ground circuit open? | -- | ||
8 |
Is voltage present on the circuit? | -- | ||
9 | Repair the short to voltage on the APP 3 signal circuit. Is the action complete? | -- | -- | |
10 | Check for a poor electrical connection at the APP sensor. Was the repair performed? | -- | ||
11 | Replace the APP module. Refer to Accelerator Pedal Position Module Replacement . Is the action complete? | -- | -- | |
12 | Replace the PCM. Important: The new PCM must be programmed. Refer to Powertrain Control Module Replacement/Programming . Is the action complete? | -- | -- | |
13 |
Does the Scan Tool indicate the diagnostic Passed? | -- | ||
14 | Does the Scan Tool display any additional undiagnosed DTCs? | -- | Go to the Applicable DTC Table | System OK |
