P0107
P0107-MANIFOLD ABSOLUTE PRESSURE SENSOR CIRCUIT LOW
Special Tools:
For a complete wiring diagram, refer to the Wiring Information.
Theory of operation
The Manifold Absolute Pressure (MAP) sensor is a transducer that varies resistance according to changes in altitude and atmospheric conditions. The MAP reading gives the Powertrain Control Module (PCM) an indication of the current air pressure within the intake manifold. The PCM uses this information to calculate fuel delivery. The MAP sensor has a 5 Volt reference circuit, a low reference circuit and a signal circuit. The PCM supplies 5 Volts to the MAP sensor on a 5 Volt reference circuit and provides a ground on a low reference circuit. The MAP sensor provides a voltage signal to the PCM on a signal circuit relative to the pressure changes.
- When Monitored:
Engine speed between 600 to 3500 RPM. Battery voltage greater than 10 Volts.
- Set Condition:
The MAP sensor signal voltage is below the minimum acceptable value. One Trip Fault. Three good trips to turn off the MIL, (MIL will illuminate and the ETC light will flash, if equipped.)
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Pre-Diagnostic Troubleshooting Procedure.
1. ACTIVE DTC
NOTE: Diagnose and repair any system voltage or sensor supply voltage DTCs before continuing with this test.
1. Start the engine and allow it to reach normal operating temperature.
WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts or fan. Do not wear loose clothing. Failure to follow these instructions may result in possible serious or fatal injury.
2. With the scan tool, select View DTCs.
Is the DTC Active at this time?
Yes
- Go To 2
No
- Perform the INTERMITTENT CONDITION diagnostic procedure. Intermittent Condition Test
2. (F856) 5 VOLT SUPPLY CIRCUIT
1. Turn the ignition off.
2. Disconnect the MAP Sensor harness connector.
3. Ignition on, engine not running.
4. Measure the voltage on the (F856) 5 Volt Supply circuit in the MAP Sensor harness connector.
Is the voltage between 4.5 to 5.2 volts?
Yes
- Go To 3
No
- Go To 7
3. MAP SENSOR
1. With the scan tool, monitor the MAP Sensor voltage with the Sensor harness connector disconnected.
NOTE: The sensor voltage should be approximately 5.0 volts with the connector disconnected.
Does the scan tool display the voltage as described above?
Yes
- Verify that there is good pin to terminal contact in the Sensor and Powertrain Control Module connectors. Replace the MAP Sensor if no problems were found with the connectors. Removal
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.
No
- Go To 4
4. (K1) MAP SIGNAL CIRCUIT SHORTED TO GROUND
1. Turn the ignition off.
2. Disconnect the C2 PCM harness connector.
3. Measure the resistance between ground and the (K1) MAP Signal circuit in the MAP Sensor harness connector.
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
1. Measure the resistance between the (K1) MAP Signal circuit and the (K900) Sensor ground circuit in the MAP Sensor harness connector.
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 6
6. EXCESSIVE RESISTANCE IN THE (K1) MAP SIGNAL CIRCUIT
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 the PCM Pinout Box (8815A) to perform diagnosis.
1. Measure the resistance of the (K1) MAP Signal circuit between the MAP Sensor harness connector and the appropriate terminal of PCM Pinout Box.
Is the resistance below 5.0 Ohms?
Yes
- Go To 9
No
- Repair the excessive resistance in the (K1) MAP Signal circuit.
- Perform the POWERTRAIN VERIFICATION TEST.Powertrain Verification Test.
7. (F856) 5 VOLT SUPPLY CIRCUIT OPEN
1. Turn the ignition off.
2. 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 the PCM Pinout Box (8815A) to perform diagnosis.
3. Measure the resistance of the (F856) 5 Volt Supply circuit from the MAP Sensor harness connector to the appropriate terminal of PCM Pinout Box.
Is the resistance below 5.0 Ohms?
Yes
- Go To 8
No
- Repair the open or excessive resistance in the (F856) 5 Volt Supply circuit.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.
8. (F856) 5 VOLT SUPPLY CIRCUIT SHORTED TO GROUND
1. Measure the resistance between ground and the (F856) 5 Volt Supply circuit in the MAP Sensor harness connector.
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 9
9. POWERTRAIN CONTROL MODULE (PCM)
1. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the MAP Sensor and the Powertrain Control Module (PCM).
2. Look for any chafed, pierced, pinched or partially broken wires.
3. Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the Sensor and Control Module connectors.
4. Perform any Technical Service Bulletins that may apply.
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. PCM/ECM/TCM Reprogramming
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.