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 engine control module (ECM) supplies 5 volts to the MAP sensor on the 5-volt reference circuit. The ECM also provides a ground on the low reference circuit. The MAP sensor provides a signal to the ECM on the MAP sensor signal circuit which is relative to the pressure changes in the manifold. The ECM should detect a low signal voltage at a low MAP, such as during an idle or a deceleration. The ECM 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 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 MAP sensor contains the following circuits:
| • | A 5-volt reference |
| • | A low reference |
| • | A MAP sensor signal |
If the ECM detects that the MAP sensor pressure/voltage is intermittently high, DTC P1106 sets.
DTC Descriptor
This diagnostic supports the following DTC:
DTC P1106 Manifold Absolute Pressure (MAP) Sensor Circuit Intermittent High Voltage
Conditions for Running the DTC
| • | DTCs P0122, P0123, P1121, and P1122 are not set. |
| • | The engine is running for more than 10 seconds. |
| • | The TP sensor is less than 20 percent if the engine speed is less than 3,000 RPM. |
| • | The TP sensor is less than 30 percent if the engine speed is more than 3,000 RPM. |
| • | DTC P1106 runs continuously once the above conditions are met. |
Conditions for Setting the DTC
The ECM detects that the MAP sensor is more than 103 kPa intermittently for more than 60 seconds.
Action Taken When the DTC Sets
| • | The malfunction indicator lamp (MIL) will not illuminate. |
| • | The ECM will store conditions which were present when the DTC was set as Failure Records data only. |
| • | This information will not be stored in the Freeze Frame data. |
Conditions for Clearing the MIL/DTC
| • | A history DTC will clear after 40 consecutive warm-up cycles without a fault. |
| • | DTCs can be cleared by using the scan tool. |
| • | Disconnect the ECM battery feed for more than 10 seconds. |
Diagnostic Aids
Inspect for the following conditions:
| • | Leaking or plugged vacuum supply line to the MAP sensor |
| • | Inspect the ECM harness connectors for backed-out terminals, improper mating, broken locks, improperly formed or damaged terminals, and poor terminal-to-wire connection. |
| • | Inspect the wiring harness for damage. If the harness appears to be OK, observe the MAP display on the scan tool while moving connectors and wiring harnesses related to the sensor. A change in the display will indicate the location of the fault. |
Reviewing the Failure Records vehicle mileage since the diagnostic test last failed may help determine how often the condition that caused the DTC to be set occurs. This may assist in diagnosing the condition.
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 | |||
1 | Did you perform the Diagnostic System Check - Engine Controls? | Go to Step 2 | |
2 |
Is DTC P0108 also set? | Go to DTC P0108 | Go to Step 3 |
Observe the manifold absolute pressure (MAP) sensor parameter with a scan tool while moving the MAP sensor connector and the engine control module (ECM) connector. Refer to Inducing Intermittent Fault Conditions in Wiring Systems. Does the scan tool indicate an abrupt change in value? | Go to Step 5 | Go to Step 4 | |
Observe the MAP sensor parameter with a scan tool while moving the wiring harness between the MAP sensor and the ECM. Refer to Inducing Intermittent Fault Conditions in Wiring Systems. Does the scan tool indicate an abrupt change in value? | Go to Step 6 | Go to Intermittent Conditions | |
5 | Repair the connector/terminal as necessary. Refer to Connector Repairs in Wiring Systems. Did you complete the repair? | Go to Step 7 | -- |
6 | Repair the harness/wiring as necessary. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 7 | -- |
7 |
Did the DTC fail this ignition? | Go to Step 2 | Go to Step 8 |
8 | Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed? | System OK | |
