Test Procedure
- DK1 CHECK FOR DIAGNOSTIC TROUBLE CODES (DTCS)
Are DTCs P1575, P2104, P2121, P2122, P2123, P2126, P2127, P2128, P2131, P2132, P2133, or P2138 present?
Yes No For DTC P1575, GO to DK2.
For all others, GO to DK4.For a lack/loss of power, GO to DK3.
For all others, GO to DIAGNOSTIC TROUBLE CODE (DTC) CHARTS AND DESCRIPTIONS . - DK2 REPEAT THE KOEO SELF-TEST NOTE: Make sure the accelerator pedal is not applied during the KOEO self-test.
- Ignition ON, engine OFF.
- Carry out the PCM self-test.
Are any DTCs present other than P1575?
Yes No DISREGARD the current diagnostic trouble code (DTC) at this time. DIAGNOSE the next DTC.
GO to DIAGNOSTIC TROUBLE CODE (DTC) CHARTS AND DESCRIPTIONS .GO to DK3. - DK3 CHECK THE ACCELERATOR PEDAL FOR OBSTRUCTION
- Ignition ON, engine OFF.
- Press the accelerator pedal fully to the floor and release.
Does the pedal move freely to the floor and back?
Yes No GO to DK4. ISOLATE and REPAIR the obstruction.
Clear the PCM DTCs. REPEAT the self-test. - DK4 CHECK THE APP SENSOR SIGNAL RANGES
- For Fiesta,
- Access the PCM and monitor the APP1__APP_D_ (PER) and APP2__APP_E_ (PER) PIDs.
- For all others,
- Access the PCM and monitor the APP1 (VOLT), APP2 (VOLT) and APP3 (VOLT) PIDs.
- Press the accelerator pedal fully to the floor and release.
ACCELERATOR PEDAL FULLY APPLIED VALUESVehicle APP1 APP2 APP3 Fiesta 60 - 70 % 60 - 70 % - E-Series 6.8L, Flex 4V 3.5L, MKS 3.7L, MKT 3.7L, Taurus 4V 3.5L 0.48 - 1.76 V 2.95 - 4.62 V 2.43 - 4.02 V Fusion 3.5L, MKZ 0.59 - 1.66 V 3.07 - 4.50 V 2.57 - 3.89 V All others 3.59 - 4.60 V 1.72 - 2.40 V - ACCELERATOR PEDAL FULLY RELEASED VALUESVehicle APP1 APP2 APP3 Fiesta 6.75 - 9.25 % 6.75 - 9.25 % - E-Series 6.8L, Flex 4V 3.5L, Fusion 3.5L, MKS 3.7L, MKT 3.7L, MKZ, Taurus 4V 3.5L 3.43 - 4.69 V 1.13 - 1.88 V 0.64 - 1.28 V All others 0.64 - 0.96 V 0.27 - 0.53 V - Are any of the APP signals out of range for the pedal fully applied and released positions?
Yes No For Fiesta with DTCs P2121, P2122 or P2123, GO to DK7.
For Fiesta with DTCs P2126, P2127, P2128 or P2138, GO to DK6.
For all others, GO to DK5.For Fiesta with DTCs P2121, P2122 or P2123, GO to DK7.
For Fiesta with DTCs P2126, P2127, P2128, P2138 or lack/loss of power, GO to DK6.
For continuous memory DTCs P2121 and P2126 with P2131, GO to DK22.
For all others, GO to DK5. - DK5 CHECK THE APPVREF VOLTAGE TO THE APP SENSOR NOTE: Only measure the circuits that apply to the vehicle being diagnosed.
- Ignition OFF.
- APP Sensor connector disconnected.
- Ignition ON, engine OFF.
- Measure the voltage between:
(+) APP Sensor Connector, Harness Side (-) APP Sensor Connector, Harness Side APPVREF APPRTN APPVREF2 APPRTN2
Are the voltages between 4.5 - 5.5 V?
Yes No For E-Series 6.8L, GO to DK8.
For Flex 3.5L,
Fusion 3.5L,
MKS 3.7L,
MKT 3.7L,
MKZ, and
Taurus 3.5L, GO to DK9.
For all others, GO to DK11.GO to PINPOINT TEST C . - DK6 CHECK THE APPVREF VOLTAGE TO THE APP SENSOR
- Ignition OFF.
- APP Sensor connector disconnected.
- Ignition ON, engine OFF.
- Measure the voltage between:
(+) APP Sensor Connector, Harness Side (-) APP Sensor Connector, Harness Side APPVREF2 APPRTN2
Is the voltage between 4.5 - 5.5 V?
Yes No For DTC P2138 or lack/loss of power, GO to DK7.
For all others, GO to DK15.GO to DK19. - DK7 CHECK THE VPWR CIRCUIT FOR AN OPEN
- Ignition OFF.
- APP Sensor connector disconnected.
- Ignition ON, engine OFF.
- Measure the voltage between:
(+) APP Sensor Connector, Harness Side (-) VPWR Ground
Is the voltage greater than 10 V?
Yes No GO to DK10. REPAIR the open circuit. Clear the PCM DTCs.
REPEAT the self-test. - DK8 E-SERIES 6.8L: CHECK THE APP SENSOR FOR THE CORRECT RESISTANCE NOTE: Make sure the accelerator pedal is fully released when taking the resistance measurements.
- Ignition OFF.
- APP Sensor connector disconnected.
- Measure the resistance between:
(+) APP Sensor Connector, Component Side (-) APP Sensor Connector, Component Side Minimum Resistance (ohms) Maximum Resistance (ohms) APP1 APPVREF 550 1, 390 APP1 APPRTN 1, 030 2, 590 APP1 APP2 2, 125 5, 335 APP1 APP3 1, 930 4, 845 APP2 APPVREF 1, 785 4, 480 APP2 APPRTN 1, 475 3, 705 APP2 APP3 2, 520 6, 330 APP3 APPVREF 1, 620 4, 070 APP3 APPRTN 1, 135 2, 860 APPVREF APPRTN 780 1, 955 APPVREF APPVREF2 0 10 APPRTN APPRTN2 0 10
Are all the resistances within specifications?
Yes No For DTCs P1575 or P2138, GO to DK22.
For DTC P2104 alone, GO to DK28.
For a lack/loss of power, the concern is elsewhere. RETURN to SYMPTOM CHARTS article for further direction.
For all others, GO to DK11.INSTALL a new APP sensor. REFER to the appropriate Acceleration Control article to INSTALL a new accelerator pedal.
Clear the PCM DTCs. REPEAT the self-test. - DK9 CHECK THE APP SENSOR FOR THE CORRECT RESISTANCE NOTE: Make sure the accelerator pedal is fully released when taking the resistance measurements.
- Ignition OFF.
- APP Sensor connector disconnected.
- Measure the resistance between:
(+) APP Sensor Connector, Component Side (-) APP Sensor Connector, Component Side Minimum Resistance (ohms) Maximum Resistance (ohms) APP1 APPVREF 600 1, 370 APP1 APPRTN 720 1, 660 APP1 APP2 1, 300 2, 960 APP1 APP3 1, 250 2, 860 APP2 APPVREF 750 1, 720 APP2 APPRTN 660 1, 520 APP2 APP3 1, 230 2, 810 APP3 APPVREF 710 1, 640 APP3 APPRTN 580 1, 340 APPVREF APPRTN 200 470 APPVREF APPVREF2 0 10 APPRTN APPRTN2 0 10
Are all the resistances within specifications?
Yes No For DTCs P1575 or P2138, GO to DK22.
For DTC P2104 alone, GO to DK28.
For a lack/loss of power, the concern is elsewhere. RETURN to SYMPTOM CHARTS article for further direction.
For all others, GO to DK11.INSTALL a new APP sensor. REFER to the appropriate Acceleration Control article to INSTALL a new accelerator pedal.
Clear the PCM DTCs. REPEAT the self-test. - DK10 CHECK THE APP SENSOR GND CIRCUIT
Is the resistance less than 5 ohms?
Yes No GO to DK11. REPAIR the open circuit. Clear the PCM DTCs.
REPEAT the self-test. - DK11 CHECK THE APP CIRCUIT FOR AN OPEN NOTE: Only measure the circuits that apply to the DTC being diagnosed.
- Ignition OFF.
- PCM connector disconnected.
- Measure the resistance between:
(+) APP Sensor Connector, Harness Side (-) PCM Connector, Harness Side APP1 APP1 APP2 APP2 APP3 APP3
Are the resistances less than 5 ohms?
Yes No GO to DK12. REPAIR the open circuit. Clear the PCM DTCs.
REPEAT the self-test. - DK12 CHECK THE APP CIRCUIT FOR A SHORT TO GROUND NOTE: Only measure the circuits that apply to the DTC being diagnosed.
- Measure the resistance between:
(+) APP Sensor Connector, Harness Side (-) APP1 Ground APP2 Ground APP3 Ground
Are the resistances greater than 10K ohms?
Yes No GO to DK13. REPAIR the short circuit. Clear the PCM DTCs.
REPEAT the self-test. - Measure the resistance between:
- DK13 CHECK THE APP CIRCUIT FOR A SHORT TO VOLTAGE NOTE: Only measure the circuits that apply to the DTC being diagnosed.
- Ignition ON, engine OFF.
- Measure the voltage between:
(+) APP Sensor Connector, Harness Side (-) APP1 Ground APP2 Ground APP3 Ground
Is any voltage present?
Yes No REPAIR the short circuit. Clear the PCM DTCs.
REPEAT the self-test.For Fiesta with DTCs P2121, P2122, P2123, P2138 or lack/loss of power, GO to DK14.
For all others, GO to DK22. - DK14 CHECK THE APP CIRCUIT FOR A SHORT
- IPC connector disconnected.
- Measure the resistance between:
(+) APP Sensor Connector, Harness Side (-) APP Sensor Connector, Harness Side APP1 APP2 APP1 APPVREF2 APP1 APPRTN2
Are the resistances greater than 10K ohms?
Yes No For Fiesta with DTC P2138 or lack/loss of power, GO to DK15.
For all others, INSTALL a new APP sensor. REFER to the appropriate Acceleration Control article to INSTALL a new accelerator pedal.
Clear the PCM DTCs. REPEAT the self-test.REPAIR the short circuit. Clear the PCM DTCs.
REPEAT the self-test. - DK15 CHECK THE APP2 SENSOR CIRCUIT FOR AN OPEN
- IPC connector disconnected.
- Measure the resistance between:
(+) APP Sensor Connector, Harness Side (-) IPC Connector, Harness Side APP2 APP2 - Pin 14
Is the resistance less than 5 ohms?
Yes No GO to DK16. REPAIR the open circuit. Clear the PCM DTCs.
REPEAT the self-test. - DK16 CHECK THE APP2 SENSOR CIRCUIT FOR A SHORT TO GROUND
Is the resistance greater than 10K ohms?
Yes No GO to DK17. REPAIR the short circuit. Clear the PCM DTCs.
REPEAT the self-test. - DK17 CHECK THE APP2 SENSOR CIRCUIT FOR A SHORT TO VOLTAGE
- Ignition ON, engine OFF.
- Measure the voltage between:
(+) APP Sensor Connector, Harness Side (-) APP2 Ground
Is any voltage present?
Yes No REPAIR the short circuit. Clear the PCM DTCs.
REPEAT the self-test.GO to DK18. - DK18 CHECK THE APP2 SENSOR CIRCUITS FOR A SHORT
- Ignition OFF.
- PCM connector disconnected.
- Measure the resistance between:
(+) APP Sensor Connector, Harness Side (-) APP Sensor Connector, Harness Side APP2 APP1 APP2 APPVREF2 APP2 APPRTN2
Are the resistances greater than 10K ohms?
Yes No GO to DK25. REPAIR the short circuit. Clear the PCM DTCs.
REPEAT the self-test. - DK19 CHECK THE APPVREF2 AND APPRTN2 CIRCUITS FOR AN OPEN
- Ignition OFF.
- IPC connector disconnected.
- Measure the resistance between:
(+) APP Sensor Connector, Harness Side (-) IPC Connector, Harness Side APPVREF2 APPVREF2 - Pin 31 APPRTN2 APPRTN2 - Pin 13
Are the resistances less than 5 ohms?
Yes No GO to DK20. REPAIR the open circuit. Clear the PCM DTCs.
REPEAT the self-test. - DK20 CHECK THE APPVREF2 CIRCUIT FOR A SHORT TO GROUND
Is the resistance greater than 10K ohms?
Yes No GO to DK21. REPAIR the short circuit. Clear the PCM DTCs.
REPEAT the self-test. - DK21 CHECK THE APPVREF2 AND APPRTN2 CIRCUITS FOR A SHORT TO VOLTAGE
- Ignition ON, engine OFF.
- Measure the voltage between:
(+) APP Sensor Connector, Harness Side (-) APPVREF2 Ground APPRTN2 Ground
Is any voltage present?
Yes No REPAIR the short circuit. Clear the PCM DTCs.
REPEAT the self-test.GO to DK27. - DK22 CHECK THE APP CIRCUIT FOR A SHORT NOTE: Only measure the circuits that apply to the vehicle being diagnosed.
- Ignition OFF.
- PCM connector disconnected.
- APP Sensor connector disconnected.
- Measure the resistance between:
(+) APP Sensor Connector, Harness Side (-) APP Sensor Connector, Harness Side APP1 APP2 APP1 APP3 APP1 APPVREF APP1 APPVREF2 APP1 APPRTN APP1 APPRTN2 APP2 APP3 APP2 APPVREF APP2 APPVREF2 APP2 APPRTN APP2 APPRTN2 APP3 APPVREF APP3 APPVREF2 APP3 APPRTN APP3 APPRTN2
Are the resistances greater than 10K ohms?
Yes No GO to DK23. REPAIR the short circuit. Clear the PCM DTCs.
REPEAT the self-test. - DK23 CHECK THE APP SENSOR CIRCUITS FOR AN INTERMITTENT CONCERN
- Wiggle, shake, and bend small sections of the wiring harness while working from the sensor to the PCM.
- Measure the resistance between:
(+) APP Sensor Connector, Harness Side (-) PCM Connector, Harness Side APP1 APP1 APP2 APP2 APP3 APP3
Are the resistances less than 5 ohms?
Yes No For E-Series 4.6L,
E-Series 5.4L,
Edge,
Escape,
Expedition,
Explorer,
F-150,
F-Series Super Duty,
Flex 3.5L GTDI,
Focus,
Fusion 2.5L,
Fusion 3.0L,
MKS 3.5L,
MKT 3.5L,
MKX,
Motorhome / Stripped Chassis / Step Van,
Mustang,
Navigator,
Taurus 3.5L GTDI, and
Transit Connect, GO to DK24.
For all others, GO to DK28.ISOLATE the concern and REPAIR as necessary.
Clear the PCM DTCs. REPEAT the self-test. - DK24 CHECK FOR DTCS
- PCM connector connected.
- Ignition ON, engine OFF.
- Carry out the PCM self-test.
Are DTCs P2122 and P2127 present?
Yes No GO to DK26. GO to DK28. - DK25 INDUCE A HIGH VOLTAGE ON THE APP2 CIRCUIT
- PCM connector connected.
- IPC connector connected.
- Connect a 5 amp fused jumper wire between the following:
Point A APP Sensor Connector, Harness Side Point B APP Sensor Connector, Harness Side APP2 APPVREF2 - Ignition ON, engine OFF.
- Access the PCM and monitor the APP2__APP_E_ (PER) PID.
Is the Percentage greater than 95%?
Yes No INSTALL a new APP sensor. REFER to the appropriate Acceleration Control article to INSTALL a new accelerator pedal.
Clear the PCM DTCs. REPEAT the self-test.GO to DK27. - DK26 SIMULATE THE OPPOSITE SIGNAL
- Ignition OFF.
- Connect a 5 amp fused jumper wire between the following:
Point A APP Sensor Connector, Harness Side Point B APP Sensor Connector, Harness Side APPVREF2 APP1 APPVREF APP2 - Ignition ON, engine OFF.
- Access the PCM and monitor the APP1 (VOLT) and APP2 (VOLT) PIDs.
Are the voltages greater than 4.5 V?
Yes No INSTALL a new APP sensor. REFER to the appropriate Acceleration Control article to INSTALL a new accelerator pedal.
Clear the PCM DTCs. REPEAT the self-test.GO to DK28. - DK27 CHECK FOR CORRECT INSTRUMENT PANEL CLUSTER (IPC) OPERATION
- Disconnect all the IPC connectors.
- Visually inspect for:
- pushed out pins
- corrosion
- Connect all the IPC connectors and make sure they seat correctly.
- Operate the system and verify the concern is still present.
Is the concern still present?
Yes No INSTALL a new IPC. REFER to the appropriate Instrumentation, Message Center, and Warning Chimes article.
Clear the PCM DTCs. REPEAT the self-test.The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. - DK28 CHECK FOR CORRECT PCM OPERATION
- Disconnect all the PCM connectors.
- Visually inspect for:
- pushed out pins
- corrosion
- Connect all the PCM connectors and make sure they seat correctly.
- Carry out the PCM self-test.
- Verify the concern is still present.
Is the concern still present?
Yes No INSTALL a new PCM. REFER to FLASH ELECTRICALLY ERASABLE PROGRAMMABLE READ ONLY MEMORY (EEPROM) , Programming the VID Block for a Replacement PCM. The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.