Circuit Description
The manifold absolute pressure (MAP) sensor measures the pressure inside the intake manifold. Pressure in the intake manifold is affected by engine speed, throttle opening, air temperature, and barometric pressure (BARO). A diaphragm within the MAP sensor is displaced by the pressure changes that occur from the varying load and operating conditions of the engine. The sensor translates this action into electrical resistance. The MAP sensor wiring includes 3 circuits. The powertrain control module (PCM) supplies a regulated 5 volts to the sensor on a 5-volt reference circuit. The PCM supplies a ground on a low reference circuit. The MAP sensor provides a signal voltage to the PCM, relative to the pressure changes, on the MAP sensor signal circuit. The PCM converts the signal voltage input to a pressure value.
Under normal operation the highest pressure that can exist in the intake manifold is equal to BARO. This occurs when the vehicle is operated at wide-open throttle (WOT) or when the ignition is on while the engine is off. Under these conditions, the PCM uses the MAP sensor to determine the current BARO. The lowest manifold pressures occur when the vehicle is idling or decelerating. MAP can range from 10 kPa, when pressures are low, to as much as 104 kPa when pressures are high, depending on the BARO. The PCM monitors the MAP sensor signal for pressure outside of the normal range. If the PCM detects that the MAP sensor pressure is excessively low, DTC P1107 sets.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC P1107 Manifold Absolute Pressure (MAP) Sensor Circuit Intermittent Low Voltage
Conditions for Running the DTC
| • | The PCM is in the run state. |
| • | DTCs P0068, P0120, P0121, P0220, P0641, P0651, P1516, P1680, P1681, P2101, P2120, P2125, P2135, P2138, P2176 are not set. |
| • | The throttle angle is more than 0 percent when engine speed is less than 1,100 RPM. |
| OR |
| • | The throttle angle is more than 9 percent when engine speed is more than 1,100 RPM. |
| • | DTC P1107 runs continuously when the above conditions are met. |
Conditions for Setting the DTC
The PCM detects that the MAP sensor pressure is less than 12 kPa intermittently for more than 30 seconds.
Action Taken When the DTC Sets
| • | The control module stores the DTC information into memory when the diagnostic runs and fails. |
| • | The malfunction indicator lamp (MIL) will not illuminate. |
| • | The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Failure Records. |
| • | The driver information center, if equipped, may display a message. |
Conditions for Clearing the DTC
| • | A current DTC Last Test Failed clears when the diagnostic runs and passes. |
| • | A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other non-emission related diagnostic. |
| • | Clear the DTC with a scan tool. |
Step | Action | Values | Yes | No |
|---|---|---|---|---|
Schematic Reference: Engine Controls Schematics Connector End View Reference: Engine Controls Connector End Views or Powertrain Control Module Connector End Views | ||||
1 | Did you perform the Diagnostic System Check - Vehicle? | -- | Go to Step 2 | |
2 |
Is DTC P0651 also set? | -- | Go to DTC P0651 | Go to Step 3 |
3 | Observe the MAP sensor parameter with the scan tool. Is the pressure less than the specified value? | 12 kPa | Go to Step 5 | Go to Step 4 |
4 |
Did the DTC fail this ignition? | -- | Go to Step 5 | Go to Underhood Electrical Center or Junction Block Replacement |
5 | Test for an intermittent and for a poor connection at the manifold absolute pressure (MAP) sensor. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs. Did you find and correct the condition? | -- | Go to Step 13 | Go to Step 6 |
6 |
Is the voltage more than the specified value? | 4.8 V | Go to Step 7 | Go to Step 8 |
7 |
Is the pressure more than the specified value? | 103 kPa | Go to Step 11 | Go to Step 9 |
8 | Test the 5-volt reference circuit between the powertrain control module (PCM) and the MAP sensor for an open. Refer to Circuit Testing and Wiring Repairs. Did you find and correct the condition? | -- | Go to Step 13 | Go to Step 10 |
9 | Test the MAP sensor signal circuit between the PCM and the MAP sensor for a short to ground or an open. Refer to Circuit Testing and Wiring Repairs. Did you find and correct the condition? | -- | Go to Step 13 | Go to Step 10 |
10 | Test for an intermittent and for a poor connection at the PCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs. Did you find and correct the condition? | -- | Go to Step 13 | Go to Step 12 |
11 | Replace the MAP sensor. Refer to Manifold Absolute Pressure Sensor Replacement. Did you complete the replacement? | -- | Go to Step 13 | -- |
12 | Replace the PCM. Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement? | -- | Go to Step 13 | -- |
13 |
Did the DTC fail this ignition? | -- | Go to Step 2 | Go to Step 14 |
14 | Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed? | -- | System OK | |
