28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM), 3.6L/Diagnosis and Testing

P0107-MANIFOLD ABSOLUTE PRESSURE SENSOR CIRCUIT LOW

Theory of Operation

The Manifold Absolute Pressure (MAP) Sensor is a transducer that varies resistance according to pressure changes in the Intake Manifold. The MAP Sensor signal provides the Powertrain Control Module (PCM) with an indication of the current air pressure within the Intake Manifold. The PCM uses this information to help calculate fuel delivery. The PCM supplies 5.0 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. The PCM receives the Barometric Pressure (BARO) Sensor reading from the MAP Sensor with the ignition on, before the engine is cranking or running.

NOTE: / Do not use shop air to clean out the MAP Sensor when diagnosing a MAP Sensor related fault as this will cause internal damage to the sensor.

When Monitored and Set Conditions

When Monitored:This diagnostic runs continuously when the following conditions are met:

  • With the ignition on.
  • Battery voltage greater than 10.4 volts.

Set Conditions:

  • The Powertrain Control Module (PCM) detects that the MAP Sensor input voltage is below the minimum acceptable value.

Default Actions:

  • MIL light will illuminate.
  • The ETC light will flash.
  • If the vehicle is equipped with the stop/start feature, the system will be disabled when this DTC is active.

Possible Causes

5-VOLT SUPPLY CIRCUIT OPEN OR SHORTED
MAP SIGNAL CIRCUIT SHORTED TO GROUND
MAP SIGNAL CIRCUIT SHORTED TO SENSOR GROUND CIRCUIT
MAP SIGNAL CIRCUIT OPEN/HIGH RESISTANCE
MAP SENSOR
POWERTRAIN CONTROL MODULE (PCM)

1.CHECK FOR AN ACTIVE DTC

1. / Start the engine and allow it to idle.
2. / With the scan tool, read DTCs and record on the repair order.

Is the DTC active or pending?
Yes

  • Go To2

No

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

2.CHECK FOR OTHER DTCS

1. / Refer to the recorded DTCs.

Are there any 5-Volt Reference High or Low DTCs active or pending?
Yes

  • Perform the applicable diagnostic procedure(s).

No

  • Go To3

3.CHECK THE (F856) 5-VOLT SUPPLY CIRCUIT FOR AN OPEN/HIGH RESISTANCE

1. / Turn the ignition off.
2. / Disconnect the MAP Sensor harness connector.
3. / Turn the ignition on.
4. / Measure the voltage on the (F856) 5-Volt Supply circuit in the MAP Sensor harness connector.

Is the voltage above 4.8 volts?
Yes

  • Go To4

No

  • Repair the (F856) 5-Volt Supply circuit for an open or high resistance.

4.CHECK THE (K1) MAP SIGNAL CIRCUIT FOR A SHORT TO GROUND

1. / Turn the ignition off.
2. / Disconnect the PCM C2 harness connector.
3. / Check for continuity between ground and the (K1) MAP Signal circuit at the MAP Sensor harness connector.

Is there continuity between ground and the (K1) MAP Signal circuit?
No

  • Go To5

Yes

  • Repair the (K1) MAP Signal circuit for a short to ground.

5.CHECK THE (K1) MAP SIGNAL CIRCUIT FOR SHORT TO THE (K900) SENSOR GROUND CIRCUIT

1. / Check for continuity between the (K1) MAP Signal circuit and the (K900) Sensor Ground circuit at the MAP Sensor harness connector.

Is there continuity between the (K1) MAP Signal circuit and the (K900) Sensor Ground circuit?
Yes

  • Go To6

No

  • Repair the (K1) MAP Signal circuit for a short to the (K900) Sensor Ground circuit.

6.CHECK THE (K1) MAP SIGNAL CIRCUIT FOR AN OPEN/HIGH RESISTANCE

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

Is the resistance below 3.0 Ohms?
Yes

  • Go To7

No

  • Repair the (K1) MAP Signal circuit for an open or high resistance.

7.CHECK THE ABILITY OF THE PCM TO READ THE MAP SENSOR SIGNAL USING A JUMPER

1. / Turn the ignition off.
2. / Reconnect the PCM C2 harness connector.
3. / Connect a jumper between the (F856) 5-Volt Supply circuit and the (K1) MAP Signal circuit at 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 4.8 volts with the jumper in place?
Yes

  • Replace the MAP Sensor in accordance with the Service Information.

No

  • Go To8

8.CHECK RELATED HARNESS CONNECTIONS

1. / Disconnect all PCM harness connectors.
2. / Disconnect all related in-line harness connections (if equipped).
3. / Disconnect the related component harness connectors.
4. / Inspect harness connectors, component connectors, and all male and female terminals for the following conditions:
  • Proper connector installation.
  • Damaged connector locks.
  • Corrosion.
  • Other signs of water intrusion.
  • Weather seal damage (if equipped).
  • Bent terminals.
  • Overheating due to a poor connection (terminal may be discolored due to excessive current draw).
  • Terminals that have been pushed back into the connector cavity.
  • Check for spread terminals and verify proper terminal tension.
Repair any conditions that are found.
5. / Connect all PCM harness connectors. Be certain that all harness connectors are fully seated and the connector locks are fully engaged.
6. / Connect all in-line harness connectors (if equipped). Be certain that all connectors are fully seated and the connector locks are fully engaged.
7. / Connect all related component harness connectors. Be certain that all connectors are fully seated and the connector locks are fully engaged.
8. / With the scan tool, erase DTCs.
9. / Test drive or operate the vehicle in accordance with the when monitored and set conditions.
10. / With the scan tool, read DTCs.

Did the DTC return?
Yes

  • Replace and program the Powertrain Control Module (PCM) in accordance with the Service Information.

No

  • Repair the poor connections.