Circuit Description
The manifold absolute pressure (MAP) sensor responds to pressure changes in the intake manifold. The pressure changes occur based on the engine load. The MAP sensor has the following circuits:
| • | 5-volt reference circuit |
| • | Low reference circuit |
| • | MAP sensor signal circuit |
The powertrain control module (PCM) supplies 5 volts to the MAP sensor on the 5-volt reference circuit. The PCM also provides a ground on the low reference circuit. The MAP sensor provides a signal to the PCM on the MAP sensor signal circuit which is relative to the pressure changes in the manifold. The PCM should detect a low signal voltage at a low MAP, such as during an idle or a deceleration. The PCM should detect a high signal voltage at a high MAP, such as the ignition is ON, with the engine OFF, or at a wide open throttle (WOT). The MAP sensor is also used in order to determine the barometric pressure (BARO). This occurs when the ignition switch is turned ON, with the engine OFF. The BARO reading may also be updated whenever the engine is operated at WOT. The PCM monitors the MAP sensor signal for voltage outside of the normal range.
The PCM calculates a predicted value for the MAP sensor based on throttle position and the engine speed. The PCM then compares the predicted value to the actual MAP sensor signal. If the MAP sensor signal is not within the predicted range, this DTC sets.
DTC Descriptor
This diagnostic procedure supports the following DTC.
DTC P0106 MAP Sensor Performance
MAP Correlation
The following table illustrates the differences between the engine conditions, the MAP sensor values, and the engine vacuum:
Engine Condition | MAP kPa | MAP Voltage | Engine Vacuum |
|---|---|---|---|
Idle | Low | Low | High |
Deceleration | Low | Low | High |
Ignition ON, Engine OFF | High | High | Low |
Wide-Open Throttle | High | High | Low |
Conditions for Running the DTC
| • | The engine speed is between 400-5,000 RPM. |
| • | The change in the engine speed is less than 125 RPM. |
| • | DTCs P0101 - P0103, P0107, P0108, P0442, P0443, P0446 or P0455, are not set. |
| • | The traction control is not active. |
| • | The A/C compressor clutch is steady. |
| • | The power steering is stable. |
| • | The change in idle air is less than 10 g/s. |
| • | The clutch switch state does not change. |
| • | The brake switch state does not change. |
| • | The conditions above exist for at least 1 second. |
Conditions for Setting the DTC
The actual MAP sensor signal is not within the predicted range for 2 seconds.
Action Taken When the DTC Sets
| • | The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails. |
| • | The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records. |
Conditions for Clearing the MIL/DTC
| • | The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail. |
| • | 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 emission related diagnostic. |
| • | Clear the MIL and the DTC with a scan tool. |
Diagnostic Aids
| • | Inspect for the following conditions: |
| - | Restrictions in the MAP sensor vacuum source |
| - | A MAP sensor seal that is missing or damaged |
| - | Vacuum hoses that are disconnected, damaged, or incorrectly routed |
| - | Intake manifold vacuum leaks |
| - | Vacuum leaks at the throttle body |
| • | If an intermittent condition exists, refer to Intermittent Conditions . |
Test Description
The numbers below refer to the step numbers on the diagnostic table.
-
This step tests the MAP sensor's ability to correctly indicate the BARO. The value shown for the MAP sensor varies with the altitude. 103 kPa is the approximate BARO that is displayed at or near sea level.
-
This step tests the MAP sensor's ability to respond to an increase in engine vacuum.
-
This step tests for a proper MAP sensor kPa with an applied vacuum.
Step | Action | Values | Yes | No |
|---|---|---|---|---|
Schematic Reference: Engine Controls Schematics Connector End View Reference: Powertrain Control Module Connector End Views or Engine Controls Connector End Views | ||||
1 | Did you perform the Diagnostic System Check-Engine Controls? | -- | Go to Step 2 | |
2 |
Important: If you were sent here from DTC P0101, proceed to step 4.
Does the DTC Pass this ignition cycle? | -- | Go to Step 3 | Go to Step 4 |
3 |
Does the DTC fail this ignition cycle? | -- | Go to Step 4 | Go to Diagnostic Aids |
4 |
Does the voltage change from below the specified value to above the specified value? | 1.0-4.0 V | Go to Step 5 | Go to DTC P0121 |
Is the kPa within the specified value of the known good vehicle? | 3 kPa | Go to Step 6 | Go to Step 10 | |
6 |
Did the voltage change value after you started the engine? | -- | Go to Step 7 | Go to Step 10 |
Does the scan tool indicate that the MAP sensor is operating normally? | -- | Go to Step 8 | Go to Step 18 | |
Observe the MAP sensor pressure with 20 inch Hg of vacuum applied to the MAP sensor. Does the scan tool indicate that the MAP sensor pressure is less than the specified value? | 34 kPa | Go to Step 9 | Go to Step 10 | |
9 | Disconnect the MAP sensor from the hand vacuum pump. Does the MAP sensor pressure return to the original value that you observed in step 5? | -- | Go to Diagnostic Aids | Go to Step 18 |
10 |
Is the voltage less than the specified value? | 0.2 V | Go to Step 11 | Go to Step 17 |
11 | Connect a 3-amp fused jumper wire between the 5-volt reference circuit of the MAP sensor and the signal circuit of the MAP sensor. Does the scan tool indicate that the MAP sensor voltage is near the specified value? | 5 V | Go to Step 12 | Go to Step 16 |
12 |
Does the voltage measure less than the specified value? | 5.2 V | Go to Step 13 | Go to Step 14 |
13 | Probe the low reference circuit of the MAP sensor with a test lamp that is connected to battery positive voltage. Does the test lamp illuminate? | -- | Go to Step 18 | Go to Step 15 |
14 | Test the 5-volt reference circuit of the MAP sensor for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 22 | Go to Step 19 |
15 | Test the low reference circuit of the MAP sensor for high resistance or an open. Refer to Testing for Continuity and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 22 | Go to Step 19 |
16 | Test the 5-volt reference and the signal circuit of the MAP sensor for high resistance. Refer to Testing for Continuity and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 22 | Go to Step 19 |
17 | Test the signal circuit of the MAP sensor for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 22 | Go to Step 19 |
18 | Test for an intermittent and for a poor connection at the MAP sensor. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 22 | Go to Step 20 |
19 | Test for an intermittent and for a poor connection at the PCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 22 | Go to Step 21 |
20 | Replace the MAP sensor. Refer to Manifold Absolute Pressure Sensor Replacement . Did you complete the replacement? | -- | Go to Step 22 | -- |
21 | Replace the PCM. Refer to Powertrain Control Module Replacement . Did you complete the replacement? | -- | Go to Step 22 | -- |
22 |
Did the DTC fail this ignition? | -- | Go to Step 2 | Go to Step 23 |
23 | Observe the Capture Info with a scan tool. Are there any DTCs that you have not diagnosed? | -- | System OK | |
