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 engine control module (ECM) supplies a regulated 5 volts to the sensor on a 5-volt reference circuit. The ECM supplies a ground on a low reference circuit. The MAP sensor provides a signal voltage to the ECM, relative to the pressure changes, on the MAP sensor signal circuit. The ECM 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 ECM 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 ECM monitors the MAP sensor signal for pressure outside of the normal range. If the ECM detects that the MAP sensor pressure is intermittently 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
| • | DTCs P0641, P0651, P1516, P1680, P1681, P2101, P2120, P2125, P2135, P2138, P2176 are not set. |
| • | The engine has been running for a period of time that is determined by the start-up coolant temperature. The time ranges from 8 seconds at less than -30°C (-22°F) to 3 seconds at more than 30°C (86°F). |
| • | The throttle angle is less than 90 percent when the engine speed is less than 1,000 RPM. |
| OR |
| • | The throttle angle is less than 98 percent when the engine speed is more than 1,000 RPM. |
| • | This DTC runs continuously within the enabling conditions. |
Conditions for Setting the DTC
The ECM detects that the MAP sensor pressure is intermittently more than 102 kPa.
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. |
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: Engine Controls Connector End Views or Engine Control Module Connector End Views | |||||||||
1 | Did you perform the Diagnostic System Check - Vehicle ? | Go to Step 2 | |||||||
2 |
Is DTC P0108, P0641, or P0651 also set? | Go to Step 3 | |||||||
Refer to Inducing Intermittent Fault Conditions and Intermittent Conditions . Is the MAP sensor parameter affected during any part of the test? | Go to Step 4 | Go to Step 8 | |||||||
4 | Test the low reference circuit between the ECM and the MAP sensor for an intermittent open or for high resistance. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 8 | Go to Step 5 | ||||||
5 |
Important: Disconnecting the ECM may eliminate the short during testing. Test the MAP sensor signal circuit between the ECM 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 8 | Go to Step 6 | ||||||
6 | 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 . Did you find and correct the condition? | Go to Step 8 | Go to Step 7 | ||||||
7 | Test for an intermittent and for a poor connection at the ECM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you complete the action? | Go to Step 8 | -- | ||||||
8 |
Did the DTC fail this ignition? | Go to Step 2 | Go to Step 9 | ||||||
9 | Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed? | System OK | |||||||
