P0107-MANIFOLD ABSOLUTE PRESSURE SENSOR CIRCUIT LOW

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:
With the ignition on and battery voltage greater than 10.4 volts.
Set Condition:
The Powertrain Control Module (PCM) detects that the MAP Sensor input voltage is below the minimum acceptable value.

Possible Causes
(F856) 5-VOLT SUPPLY CIRCUIT SHORTED TO GROUND
(K1) MAP SIGNAL CIRCUIT SHORTED TO GROUND
(F856) 5-VOLT SUPPLY CIRCUIT SHORTED TO (K900) SENSOR GROUND CIRCUIT
(K1) MAP SIGNAL CIRCUIT SHORTED TO (K900) SENSOR GROUND CIRCUIT
(F856) 5-VOLT SUPPLY CIRCUIT OPEN OR HIGH RESISTANCE
(K1) MAP SIGNAL CIRCUIT OPEN OR HIGH RESISTANCE
MAP SENSOR
POWERTRAIN CONTROL MODULE (PCM)

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).

1. DTC IS ACTIVE

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 status Active for this DTC?

Yes

Go To 2

Perform the INTERMITTENT CONDITION diagnostic procedure. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).

2. (F856) 5-VOLT SUPPLY CIRCUIT VOLTAGE

1.	Turn the ignition off.

2.	Disconnect the MAP Sensor harness connector.

3.	Turn the ignition on.

4.	Measure the voltage of the (F856) 5-Volt Supply circuit in the MAP Sensor harness connector.

Is the voltage above 4.5 volts?

Yes

Go To 6

Go To 3

3. (F856) 5-VOLT SUPPLY CIRCUIT SHORTED TO GROUND

1.	Turn the ignition on.

2.	Disconnect the PCM C2 harness connector.

3.	Measure the resistance between ground and the (F856) 5-Volt Supply circuit in the MAP Sensor harness connector.

Is the resistance above 1000 Ohms?

Yes

Go To 4

Repair the (F856) 5-Volt Supply circuit for a short to ground.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).

4. (F856) 5-VOLT SUPPLY CIRCUIT SHORTED TO THE (K900) SENSOR GROUND CIRCUIT

1.	Measure the resistance between the (F856) 5-Volt Supply circuit and the (K900) Sensor Ground circuit in the MAP Sensor harness connector.

Is the resistance above 100 Ohms?

Yes

Go To 5

Repair the (F856) 5-Volt Supply circuit for a short to the (K900) Sensor Ground circuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).

5. (F856) 5 VOLT SUPPLY CIRCUIT OPEN OR HIGH RESISTANCE

1.	Measure the resistance of the (F856) 5-Volt Supply circuit between the MAP Sensor harness connector and the PCM C2 harness connector.

Is the resistance below 5.0 Ohms?

Yes

Go To 10

Repair the (F856) 5-Volt Supply circuit for an open circuit or high resistance.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).

6. (K1) MAP SIGNAL CIRCUIT SHORTED TO GROUND

1.	Turn the ignition off.

2.	Disconnect the PCM C2 harness connector.

3.	Measure the resistance between ground and the (K1) MAP Signal circuit in the MAP Sensor harness connector.

Is the resistance above 100 Ohms?

Yes

Go To 7

Repair the (K1) MAP Signal circuit for a short to ground.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).

7. (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 above 100 Ohms?

Yes

Go To 8

Repair the (K1) MAP Signal circuit for a short to the (K900) Sensor Ground circuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).

8. (K1) MAP SIGNAL CIRCUIT OPEN OR HIGH RESISTANCE

1.	Measure the resistance of the (K1) MAP Signal circuit between the MAP Sensor harness connector and the PCM C2 harness connector.

Is the resistance below 5.0 Ohms?

Yes

Go To 9

Repair the (K1) MAP Signal circuit for an open circuit or high resistance.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).

9. MAP SENSOR

1.	Turn the ignition off.

2.	Connect the PCM C2 harness connector.

3.	Connect a jumper wire between the (F856) 5 Volt Supply circuit and the (K1) MAP Signal circuit in the MAP Sensor harness connector.

4.	Turn the ignition on.

5.	With the scan tool, read the MAP Sensor signal voltage.

Is the voltage above 4.5 volts with the jumper wire in place?

Yes

Replace the MAP Sensor in accordance with the Service Information. (Refer to 14 - Fuel System/Fuel Injection/SENSOR, Manifold Air Pressure (MAP) - Removal).
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).

Go To 10

10. 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.

4.	Monitor the scan tool data relative to this circuit and wiggle test the wiring and connectors.

5.	Look for the data to change or for the DTC to reset during the wiggle test.

6.	Perform any Technical Service Bulletins that may apply.

Were any problems found?

Yes

Repair as necessary.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).

Replace and program the Powertrain Control Module (PCM) in accordance with the Service Information. (Refer to 08 - Electrical/8E - Electronic Control Modules/MODULE, Powertrain Control - Removal) .
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).

P0107-MANIFOLD ABSOLUTE PRESSURE SENSOR CIRCUIT LOW

P0107-MANIFOLD ABSOLUTE PRESSURE SENSOR CIRCUIT LOW

Theory of operation

Possible Causes