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.
If the PCM detects a MAP sensor signal voltage that is excessively high, DTC P1106 sets.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC P1106 Manifold Absolute Pressure (MAP) Sensor Circuit Intermittent High Voltage
Conditions for Running the DTC
| • | The engine has been running for a length of time that is determined by the startup coolant temperature. The length of time ranges from 5.5 minutes at less than -30°C (-22°F) to 10 seconds at more than 30°C (86°F). |
| • | DTC P0068, P0120, P0220, P1516, P2101, P2108, P2120, P2125, P2135, P2138 are not set. |
| • | The throttle angle is less than 2 percent when the engine speed is less than 3,000 RPM. |
| OR |
| • | The throttle angle is more than 30 percent when the engine speed is more than 3,000 RPM. |
Conditions for Setting the DTC
| • | The PCM detects that the MAP sensor voltage is intermittently more than 4.3 volts. |
| • | This diagnostic runs continuously. |
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. |
Diagnostic Aids
This DTC may set due to poor idle characteristics. A possible cause may be uncontrolled fueling due to an open or high resistance in the HO2S 1 low signal circuit. Before replacing any component, ensure that this condition does not exist.
Test Description
The number below refers to the step number on the diagnostic table.
Step | Action | 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 - Vehicle? | Go to Step 2 | |||||||||
2 |
Does the scan tool display DTC P0108 or P0641 set? | Go to Step 3 | |||||||||
Is the MAP sensor voltage affected during any part of the test? | Go to Step 4 | Go to Step 9 | |||||||||
4 | Test the low reference circuit between the PCM and the MAP sensor for an intermittent open or a high resistance. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 9 | Go to Step 5 | ||||||||
5 |
Important: Disconnecting the PCM may eliminate the short during the testing. Test the MAP sensor signal circuit between the PCM and the MAP sensor for an intermittent short to voltage. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 9 | Go to Step 6 | ||||||||
6 | Test for an intermittent and for a poor connection at the MAP sensor. Refer to Testing for Continuity and Connector Repairs . Did you find and correct the condition? | Go to Step 9 | Go to Step 7 | ||||||||
7 | Test the HO2S 1 low signal circuit for an open or high resistance. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 9 | Go to Step 8 | ||||||||
8 | Test for an intermittent and for a poor connection at the PCM. Refer to Testing for Continuity and Connector Repairs . Did you find and correct the condition? | Go to Step 9 | |||||||||
9 |
Did the DTC fail this ignition? | Go to Step 2 | Go to Step 10 | ||||||||
10 | Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed? | System OK | |||||||||
