Test Procedure
- DK1 CHECK FOR DTCS
Are DTCs P1575, P2122, P2123, P2127, P2128, or P2138 present?
Yes No GO to DK2 . For a lack/loss of power symptom, GO to DK2 .
For all others, RETURN to SYMPTOM CHARTS for further direction. - DK2 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 DK3 . ISOLATE and REPAIR the obstruction.
Clear the PCM DTCs. REPEAT the self-test. - DK3 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 APPVREF1 - Pin 1 APPRTN1 - Pin 3 APPVREF2 - Pin 6 APPRTN2 - Pin 4
Are the voltages between 4.5 - 5.5 V?
Yes No GO to DK4 . GO to PINPOINT TEST C . - DK4 CHECK THE APP CIRCUIT FOR AN OPEN
- Ignition OFF.
- PCM connector disconnected.
- Measure the resistance between:
(+) APP Sensor Connector, Harness Side (-) PCM Connector, Harness Side APP1 - Pin 2 APP1 - Pin B30 APP2 - Pin 5 APP2 - Pin B29
Are the resistances less than 5 ohms?
Yes No GO to DK5 . REPAIR the open circuit. Clear the PCM DTCs. REPEAT the self-test. - DK5 CHECK THE APP CIRCUIT FOR A SHORT TO GROUND
- Measure the resistance between:
(+) APP Sensor Connector, Harness Side (-) APP1 - Pin 2 Ground APP2 - Pin 5 Ground
Are the resistances greater than 10K ohms?
Yes No GO to DK6 . REPAIR the short circuit. Clear the PCM DTCs. REPEAT the self-test. - Measure the resistance between:
- DK6 CHECK THE APP CIRCUIT FOR A SHORT TO VOLTAGE
- Ignition ON, engine OFF.
- Measure the voltage between:
(+) APP Sensor Connector, Harness Side (-) APP1 - Pin 2 Ground APP2 - Pin 5 Ground
Is any voltage present?
Yes No REPAIR the short circuit. Clear the PCM DTCs. REPEAT the self-test. GO to DK7 . - DK7 CHECK THE APP SENSOR CIRCUITS FOR A SHORT
- Ignition OFF.
- Measure the resistance between:
(+) APP Sensor Connector, Harness Side (-) APP Sensor Connector, Harness Side APP1 - Pin 2 APP2 - Pin 5 APP1 - Pin 2 APPVREF1 - Pin 1 APP1 - Pin 2 APPVREF2 - Pin 6 APP1 - Pin 2 APPRTN1 - Pin 3 APP1 - Pin 2 APPRTN2 - Pin 4 APP2 - Pin 5 APPVREF1 - Pin 1 APP2 - Pin 5 APPVREF2 - Pin 6 APP2 - Pin 5 APPRTN1 - Pin 3 APP2 - Pin 5 APPRTN2 - Pin 4
Are the resistances greater than 10K ohms?
Yes No GO to DK8 . REPAIR the short circuit. Clear the PCM DTCs. REPEAT the self-test. - DK8 SIMULATE THE OPPOSITE SIGNAL
- Ignition OFF.
- PCM connector connected.
- Access the PCM and monitor the APP1 (VOLT) and APP2 (VOLT) PIDs.
- Record the APP1 and APP2 PID values.
- Connect a 5 amp fused jumper wire between the following:
Point A APP Sensor Connector, Harness Side Point B APP Sensor Connector, Harness Side APP1 - Pin 2 APPVREF1 - Pin 1 APP2 - Pin 5 APPVREF2 - Pin 6 - Record the APP1 and APP2 PID values.
Do the PID values change?
Yes No INSTALL a new APP sensor. REFER to the appropriate article, Acceleration Control to INSTALL a new accelerator pedal. Clear the PCM DTCs. REPEAT the self-test. GO to DK9 . - DK9 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.