P0107

P0107-MANIFOLD ABSOLUTE PRESSURE SENSOR CIRCUIT LOW





For a complete wiring diagram Refer to Diagrams/Electrical.

Theory of Operation


The Electronic Control Module (ECM) provides a 5-volt supply to the intake manifold pressure sensor on the sensor supply circuit. The ECM also provides a ground on the sensor return circuit. The intake manifold pressure sensor provides a signal to the ECM on the intake manifold pressure sensor signal circuit. This sensor signal voltage changes based on the pressure in the intake manifold. The ECM will detect a low signal voltage at operating conditions such as during an idle or a deceleration. The ECM will detect a high signal voltage during high engine load operating conditions. When the fault is active, the ECM illuminates the MIL light immediately when the diagnostic runs and fails. During this time a default value is used of the intake manifold pressure reading. The ECM will turn off the MIL light after the diagnostic runs and passes in 4 consecutive drive cycles. This fault may cause a derate in power output.

- When Monitored:
With the ignition on and battery voltage greater than 10.4 volts.

- Set Condition:
When the fault is active, the ECM illuminates the MIL light immediately when the diagnostic runs and fails. During this time a default value is used of the intake manifold pressure reading.







Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Initial Inspection and Diagnostic Overview


Diagnostic Test


1. OTHER DTC'S
Turn the ignition on.
With the scan tool, read the Engine DTC's.
Is there a 5-volt Supply DTC set?

Yes


- Repair 5-volt Supply DTC.
- Perform POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test


No


- Go To 2



2. P0108 SET
With the scan tool, read DTC's.
Is P0108 Active?

Yes


- Go to 3


No


- Refer to the INTERMITTENT CONDITION - DIESEL Symptom. Intermittent Condition



3. HIGH VOLTAGE




Turn the ignition off.
Disconnect the MAP sensor harness connector.

NOTE: Check connectors - Clean/repair as necessary.

Check connectors - Clean/repair as necessary.
Turn the ignition on.
Measure the voltage between the (F855) 5-volt supply circuit and sensor (K916) return circuit of the MAP sensor harness connector.
Is the voltage between 4.5 and 5.5 volts?

Yes


- Go To 4


No


- Go To 5



4. MAP SENSOR




While monitoring the scan tool, jumper the (F855) 5-volt supply circuit to the (K37) signal circuit in the MAP sensor harness connector.
Did the P0108-MAP SENSOR VOLTAGE TOO HIGH, DTC set?

Yes


- Replace the MAP sensor.
- Perform POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test


No


- Go To 5



5. (K37) SIGNAL CIRCUIT SHORTED TO (K916) SENSOR RETURN CIRCUIT




Turn the ignition off.
Disconnect the ECM harness 60 pin connector.

NOTE: Check connectors - Clean/repair as necessary.

Measure the resistance between the (K37) signal circuit and (K916) sensor return circuit in the MAP sensor harness connector.
Is the resistance greater than 100 K Ohms?

No


- Repair (K37) signal circuit shorted to (K916) sensor return circuit or replace harness.
- Perform POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test


Yes


- Go To 6



6. (F855) 5-VOLT SUPPLY CIRCUIT SHORTED TO (K916) SENSOR RETURN CIRCUIT




Measure the resistance between the (F855) 5-volt supply circuit and (K916) sensor return circuit in the MAP sensor harness connector.
Is the resistance greater than 100 K Ohms?

No


- Repair (F855) 5-volt supply circuit shorted to (K916)) sensor return circuit or replace harness.
- Perform POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test


Yes


- Go To 7



7. (K37) SIGNAL CIRCUIT OPEN




Measure the resistance of the (K37) signal circuit between the MAP sensor harness connector and 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 - 6.7L. Powertrain Verification Test



8. (F855) 5-VOLT SUPPLY CIRCUIT OPEN




Measure the resistance of the (F855) 5-volt supply circuit between the MAP sensor harness connector and the ECM harness connector.
Is the resistance less than 10 Ohms?

Yes


- Go To 9


No


- Repair or replace the engine harness.
- Perform POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test



9. MAP SENSOR SIGNAL (K37) CIRCUIT SHORTED TO GROUND




Measure the resistance between the MAP Sensor Signal (K37) circuit and the Battery negative terminal.
Is the resistance above 100k ohms?

Yes


- Go To10


No


- Repair the MAP Sensor (K37) Signal circuit for a short to ground.
- Perform POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test



10. (F855) 5-VOLT SUPPLY CIRCUIT SHORTED TO (K916) RETURN CIRCUIT OR GROUND




Measure the resistance between the (F855) 5-volt supply circuit in the sensor harness connector and battery negative.
Is the resistance above 100k ohms?

Yes


- Go To 11


No


- Test Complete.



11. ECM




Reconnect the C1 ECM harness connector.
While monitoring the scan tool, jumper the (F855) 5-volt supply circuit to the (K37) signal circuit in the map sensor harness connector.
Did the P0108-MAP SENSOR VOLTAGE TOO HIGH, DTC set?

Yes


- Test Complete.


No


- Replace and program the ECM.
- Perform POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test