DTC P0228 Accelerator Pedal Position (APP) Sensor 3 Circuit High Voltage. GMC Truck Savana 1999

For 1990-2009 cars only

Makes 🢒 GMC_Truck 🢒 1999 🢒 Savana 🢒 DTC 🢒 DTC P0228 Accelerator Pedal Position (APP) Sensor 3 Circuit High Voltage

Engine Controls Components
Cell 22: Cruise Controls
OBD II Symbol Description Notice
Handling ESD Sensitive Parts Notice
Handling ESD Sensitive Parts Notice

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 Running the DTC

The ignition switch is in the ON position.

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 powertrain control module (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 is stored in the Failure Records.

Conditions for Clearing the MIL/DTC

•	The PCM will turn the MIL off after 3 consecutive trips without a fault condition.

•	A history DTC clears after 40 consecutive warm-up cycles, if this or any other emission related diagnostic does not report any failures.

•	The scan tool Clear Info function was used.

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 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 the WOT position.

Test Description

The numbers below refer to the step numbers on the diagnostic table:

This step determines if PO228 is a hard failure or an intermittent condition.

This step checks for an open in the ground circuit.

This step checks for a short to power or a bad APP module.

This step ensures that the replacement PCM, which utilizes an electrically erasable programmable read only memory (EEPROM), is programmed when installed.

Step	Action	Values	Yes	No
1	Important: Before clearing the DTCs, use the scan tool Capture Info to save the Freeze Frame and Failure Records for reference. The data in the control module is deleted once the Clear Info function is used. Did you perform the Powertrain On-Board Diagnostic (OBD) System Check?	--	Go to Step 2	Go to Powertrain On Board Diagnostic (OBD) System Check
2	Turn ON the ignition leaving the engine OFF. With the throttle closed, observe the APP 3 display on the scan tool. Is APP 3 more than or equal to the specified value?	4.75 V	Go to Step 4	Go to Step 3
3	The DTC is intermittent. If no additional DTCs are stored, refer to Diagnostic Aids. If additional DTCs are stored, refer to the applicable DTC tables first. Are any additional DTCs stored?	--	Go to the applicable DTC table	Go to Diagnostic Aids
4	Disconnect the APP sensor harness connector. Probe the APP 3 sensor ground circuit at the APP sensor harness connector with a unpowered test lamp connected to B+. Is the test lamp ON?	--	Go to Step 5	Go to Step 7
5	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	Go to Step 8	Go to Step 6
6	Check for an open on the APP 3 sensor signal circuit. If the APP 3 sensor signal circuit is open, repair as necessary. Refer to Wiring Repairs in Wiring Systems. Did you perform a repair?	--	Go to Step 14	Go to Step 12
7	Check for an open sensor ground circuit. If a problem is found, repair as necessary. Refer to Wiring Repairs in Wiring Systems. Did you perform a repair?	--	Go to Step 14	Go to Step 12
8	Verify the ignition is ON with the engine OFF. Verify the APP harness is still disconnected from the APP module. With a DMM set to the mA scale, measure the current between the APP 3 signal circuit and the ground circuit at the harness connector Is the current more than the specified value?	30 mA	Go to Step 9	Go to Step 10
9	Repair the short to voltage on the APP 3 signal circuit. Refer to Wiring Repairs in Wiring Systems. Is the action complete?	--	Go to Step 14	--
10	Check for a poor electrical connection at the APP sensor. Repair as necessary. Refer to Wiring Repairs in Wiring Systems. Did you perform a repair?	--	Go to Step 14	Go to Step 11
11	Replace the APP module. Refer to Accelerator Pedal Position Module Replacement . Is the action complete?	--	Go to Step 14	--
12	Check for a poor electrical connection at the PCM sensor. Repair as necessary. Refer to Wiring Repairs in Wiring Systems. Did you perform a repair?	--	Go to Step 14	Go to Step 13
13	Important: The new PCM must be programmed. Replace the PCM. Refer to Powertrain Control Module Replacement/Programming . Is the action complete?	--	Go to Step 14	--
14	Use a scan tool in order to clear the DTCs. Start engine. Allow the engine to idle until the normal operating temperature is reached. Select DTC and the Specific DTC function. Enter the DTC number that was set. Operate the vehicle within the Conditions for Setting this DTC until the scan tool indicates the diagnostic Ran. Does the scan tool indicate the diagnostic Passed?	--	Go to Step 15	Go to Step 2
15	Does the scan tool display any additional undiagnosed DTCs?	--	Go to the applicable DTC Table	System OK