P0107 INLET AIR PRESSURE SENSOR VOLTAGE TOO LOW

When Monitored and Set Condition:

When Monitored: With the ignition on and battery voltage greater than 10.4 volts.
Set Condition: The circuit voltage to the ECM falls below a calibrated threshold for a certain period of time.

POSSIBLE CAUSES

• OTHER DTC'S PRESENT
• INLET AIR PRESSURE SENSOR
• INLET AIR SENSOR (K69) SIGNAL CIRCUIT SHORTED TO THE (Y502) RETURN CIRCUIT
• INLET AIR PRESSURE SENSOR (Y501) SUPPLY CIRCUIT SHORTED TO THE RETURN
• CIRCUIT
• (K69) SIGNAL CIRCUIT OPEN
• (Y501) 5-VOLT SUPPLY CIRCUIT OPEN
• (K69) SIGNAL CIRCUIT SHORTED TO GROUND
• (Y501) 5-VOLT SUPPLY CIRCUIT SHORTED TO GROUND
• ECM
• INTERMITTENT CONDITION

DIAGNOSTIC PROCEDURE

NOTE: Refer to VERIFICATION TESTS for appropriate verification test procedures.

1. Ignition on, engine not running. With the DRBIII®, read DTCs. Do you have multiple DTCs?
   Yes --> Repair other DTCs first. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL).
   No --> Go To 2
2. Disconnect the Inlet Air Pressure sensor harness connector. Check connectors - Clean/repair as necessary. Measure the voltage between the (Y501) 5-volt supply circuit and (Y502) return circuit of the sensor harness connector. Is the voltage between 4.5 and 5.5 volts?
   Yes --> Go To 3
   No --> Go To 5
3. While monitoring DRBIII®, use a jumper wire to connect the (Y501) 5-volt supply circuit with the (K69) signal circuit at the sensor harness connector. Does the DRBIII® show a pressure sensor out of range high DTC?
   Yes --> Replace the Inlet Air Temperature/Pressure sensor. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL).
   No --> Go To 4
4. Turn the ignition off. Disconnect the ECM harness connector. Check connectors - Clean/repair as necessary. Measure the resistance between the (K69) signal circuit and (Y502) return circuit in the Inlet Air pressure sensor harness connector. Is the resistance greater than 100K Ohms?
   Yes --> Go To 5
   No --> Repair or replace wiring harness. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL).
5. Measure the resistance between the (Y501) 5-volt supply circuit and (Y502) return circuit in the Inlet Air Pressure sensor harness connector. Is the resistance greater than 100K Ohms?
   Yes --> Go To 6
   No --> Repair the short or replace the harness. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL).
6. Measure the resistance between the (K69) signal circuit in the Inlet Air Pressure sensor harness connector and the (K69) signal circuit in the ECM harness connector. Is the resistance less than 10 Ohms?
   Yes --> Go To 7
   No --> Repair or replace the open wiring harness. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL).
7. 7. Measure the resistance between the (Y501) 5-volt supply circuit in the Inlet Air Pressure sensor harness connector with the (Y501) 5-volt supply circuit in the ECM harness connector. Is the resistance less than 10 Ohms?
   Yes --> Go To 8
   No --> Repair or replace the Engine harness. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL).
8. Measure the resistance between the (K69) signal circuit in the inlet Air Pressure sensor connector and battery negative. Is the resistance greater than 100 K Ohms?
   Yes --> Go To 9
   No --> Repair the (K69) signal circuit shorted to ground or replace the wire harness. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL).
9. Measure the resistance between the (Y501) 5-volt supply Circuit in the Inlet Air Pressure sensor harness connector and battery negative. Is the resistance greater than 100 K Ohms?
   Yes --> Go To 10
   No --> Repair the (Y501) 5-volt supply circuit shorted to ground or replace the wire harness. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL).
10. Install the ECM harness connector. Turn the ignition on. While monitoring DRBIII®, use a jumper wire to connect the (Y501) 5-volt supply circuit with the (K69) signal circuit at the sensor harness connector. Does the DRBIII® show a pressure sensor out of range high DTC?
    Yes --> Refer to the SYMPTOM: INTERMITTENT CONDITION Symptom (Diagnostic Procedure). Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL).
    No --> Replace the ECM. Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL).