Circuit/System Verification
1. Ignition ON, observe the DTC information with a scan tool. Verify that DTC P0641 or P0651 are not set.
锟斤拷If a DTC is set, refer to DTC P0641 or P0651 (ECM) (See: P Code Charts/P0641) for further diagnosis.
2. Observe the scan tool APP Sensor 1 and 2 voltage parameters. Verify both of the APP sensor voltages are between 0.32-4.75 V.
3. Rapidly depress the accelerator pedal from the rest position to the wide open throttle position (WOT) and release pedal. Repeat the procedure
several times. DTCs P2120, P2122, P2123, P2125, P2127, P2128, or P2138 should not set.
4. Slowly depress the accelerator pedal to WOT and then slowly return the pedal to closed throttle. Repeat the procedure several times. DTCs
P2120, P2122, P2123, P2125, P2127, P2128, or P2138 should not set.
5. Observe the scan tool APP sensor 1 and 2 parameter. The scan tool should display Agree.
6. Clear the DTCs with the scan tool. Operate the vehicle within the Conditions for Running the DTC or within the conditions that you observed
from the Freeze Frame/Failure Records.
7. Ignition ON, observe the DTC information with a scan tool. Verify that DTC P2120 or P2125 are not the only APP sensor DTCs set.
锟斤拷If DTC P2120 or P2125 are the only DTCs set, replace the ECM.
8. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the
conditions that you observed from the Freeze Frame/Failure Records data.
Circuit/System Testing
1. Ignition OFF, disconnect the harness connector at the accelerator pedal.
2. Ignition OFF for 1 minute, test for less than 5 ohm between the appropriate low reference circuit terminal listed below and ground.
* APP sensor 1 terminal F or 4
* APP sensor 2 terminal A or 5
锟斤拷If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit/connections test normal, replace
the ECM.
3. Ignition ON, test for 4.8-5.2 V between the appropriate 5 V reference circuit terminal listed below and ground.
* APP sensor 1 terminal D or 2
* APP sensor 2 terminal C or 1
锟斤拷If less than the specified range, test the 5 V reference circuit for a short to ground or open/high resistance. If the circuit/connections test
normal, replace the ECM.
锟斤拷If greater than the specified range, test the 5 V reference circuit for a short to voltage. If the circuit/connections test normal, replace the
ECM.
4. Observe the scan tool APP sensor 1 voltage parameter. Verify the voltage is less than 0.3 V.
锟斤拷If greater than the specified range, test the signal circuit terminal E or 3 for a short to voltage. If the circuit/connections test normal,
replace the ECM.
5. Observe the scan tool APP sensor 2 voltage parameter. Verify the voltage is less than 0.3 V.
锟斤拷If greater than the specified range, test the signal circuit terminal B or 6 for a short to voltage. If the circuit/connections test normal,
replace the ECM.
6. Connect a 3 A fused jumper wire between the APP sensor 1 signal circuit terminal E or 3 and the 5 V reference circuit terminal C or 1. Verify
the APP sensor 1 voltage parameter is greater than 4.8 V.
锟斤拷If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit/connections test
normal, replace the ECM.
7. Connect a 3 A fused jumper wire between the APP sensor 2 signal circuit terminal B or 6 and the 5 V reference circuit terminal C or 1.
Verify the APP sensor 2 voltage parameter is greater than 4.8 V.
锟斤拷If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit/connections test
normal, replace the ECM.
8. If all circuits/connections test normal, test or replace the Accelerator Pedal Assembly.
Repair Instructions
Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the repair.
