P0107
P0107-MANIFOLD ABSOLUTE PRESSURE SENSOR CIRCUIT LOWP0107-Manifold Absolute Pressure Sensor Circuit Low:
WHEN MONITORED
Engine speed between 600 to 3500 RPM. Battery voltage greater than 10 volts.
SET CONDITION
The MAP sensor signal voltage is below 0.08 of a volt for 3.0 seconds. One Trip Fault. Three good trips to turn off the MIL, (5.7L ETC light will flash.)
POSSIBLE CAUSES
- (F856) 5-volt supply circuit open
- (F856) 5-volt supply circuit shorted to ground
- (K1) MAP signal circuit shorted to ground
- (K1) MAP signal circuit shorted to the (K900) sensor ground circuit
- MAP sensor
- PCM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding.
Diagnostic Test
1. MAP SENSOR VOLTAGE BELOW 0.08 OF A VOLT
Ignition on, engine not running.
With a scan tool, read the MAP Sensor voltage.
Q: Is the voltage below 0.08 of a volt?
YES: Go To 2
NO: Refer to the INTERMITTENT CONDITION Diagnostic Procedure. Component Tests and General Diagnostics
Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
2. (F856) 5-VOLT SUPPLY CIRCUIT
Turn the ignition off.
Disconnect the MAP Sensor harness connector.
Ignition on, engine not running.
Measure the voltage on the (F856) 5-volt Supply circuit in the MAP Sensor harness connector.
Q: Is the voltage between 4.5 to 5.2 volts?
YES: Go To 3
NO: Go To 6
3. MAP SENSOR
With a scan tool, monitor the MAP Sensor voltage with the Sensor harness connector disconnected.
Q: Is the voltage above 4.5 volts?
YES: Replace the MAP Sensor. Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
NO: Go To 4
4. (K1) MAP SIGNAL CIRCUIT SHORTED TO GROUND
Turn the ignition off.
Disconnect the C2 PCM harness connector.
Measure the resistance between ground and the (K1) MAP Signal circuit in the MAP Sensor harness connector.
Q: Is the resistance below 100 ohms?
YES: Repair the short to ground in the (K1) MAP Signal circuit. Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
NO: Go To 5
5. (K1) MAP SIGNAL CIRCUIT SHORTED TO THE (K900) SENSOR GROUND CIRCUIT
Measure the resistance between the (K1) MAP Signal circuit and the (K900) Sensor ground circuit in the MAP Sensor harness connector.
Q: Is the resistance below 100 ohms?
YES: Repair the short between the (K900) Sensor ground and the (K1) MAP Signal circuit. Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
NO: Go To 8
6. (F856) 5-VOLT SUPPLY CIRCUIT OPEN
Turn the ignition off.
Disconnect the C1 PCM harness connector.
CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install Miller Special Tool #8815 to perform diagnosis.
Measure the resistance of the (F856) 5-volt Supply circuit from the MAP Sensor harness connector to the appropriate terminal of special tool #8815.
Q: Is the resistance below 5.0 ohms?
YES: Go To 7
NO: Repair the open in the (F856) 5-volt Supply circuit. Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
7. (F856) 5-VOLT SUPPLY CIRCUIT SHORTED TO GROUND
Measure the resistance between ground and the (F856) 5-volt Supply circuit in the MAP Sensor harness connector.
Q: Is the resistance below 100 ohms?
YES: Repair the short to ground in the (F856) 5-volt Supply circuit. Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
NO: Go To 8
8. PCM
NOTE: Before continuing, check the PCM harness connector terminals for corrosion, damage, or terminal push out. Repair as necessary.
Using the schematics as a guide, inspect the wire harness and connectors. Pay particular attention to all Power and Ground circuits.
Q: Were there any problems found?
YES: Repair as necessary. Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test
NO: Replace and program the Powertrain Control Module. Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test