Circuit Description
The accelerator pedal position (APP) module provides a voltage signal that changes relative to the accelerator pedal position. There are three sensors located within the APP module that are scaled differently.
Conditions for Running the DTC
The ignition switch in the on position.
Conditions for Setting the DTC
| • | The voltage is less than 0.25 volts on the APP 3 sensor. |
| • | All disgnostic set conditions 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, if this or any other emmision related diagnostic does not report any failures. |
| • | 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 during idle. The voltage should decrease at a steady rate as the throttle is moved toward a wide open throttle (WOT). Also, 90 percent 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 will determine if DTC P0227 is the result of a hard failure or an intermittent condition.
-
This step checks the PCM and wiring.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 |
Important: Before clearing any DTCs, use the scan tool Capture Info to save the Freeze Frame and Failure Records for reference. The control module's data is deleted once the Clear Info function is used. Did you perform the Powertrain On-Board Diagnostic (OBD) System Check? | -- | ||
Is the APP 3 voltage less than or equal to the specified value? | 0.25 V | |||
The DTC is intermittent. If no additional DTCs are stored, refer to Diagnostic Aids. If additional DTCs were stored, refer to those table(s) first. Are any additional DTCs stored? | -- | Go to the applicable DTC table | Go to Diagnostic Aids | |
4 |
Is the voltage at the specified value? | 5 V | ||
5 | Use J 39200 DMM in order to probe the APP 3 signal circuit at the APP harness. Is the voltage at the specified value? | 4.8 V | ||
6 |
Was the 5 volt reference circuit open or shorted to ground? | -- | ||
7 | Check the 5 volt reference circuit for a proper connection at the PCM and replace terminal if necessary. Did the terminal require replacement? | -- | ||
8 |
Was the APP 3 signal circuit open or shorted to ground? | -- | ||
9 | Check the APP 3 sensor signal circuit for a proper connection at the PCM and replace terminal if necessary. Did the terminal require replacement? | -- | ||
10 | Check for a proper electrical connection at the APP sensor. Repair as necessary. Refer to Wiring Repairs . Did you perform the repair? | -- | ||
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 |
