P0106

DTC P0106

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 the 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 in order to determine the current BARO. The lowest manifold pressures occur when the vehicle is idling or decelerating. MAP can range from 19 kPa when pressures are low, to as much as 104 kPa when pressures are high, depending on the BARO.

Within the ECM, the diagnostic has the ability to determine an inaccurate input from the MAP sensor. Calibrated within the diagnostics are estimates for MAP based on throttle position and engine speed. The diagnostic compares the estimated value to the actual sensor input. If the ECM detects that the MAP sensor input is not within a calibrated limit of the estimated value, DTC P0106 sets.

DTC DESCRIPTOR
This diagnostic procedure supports the following DTC:
DTC P0106 Barometric Pressure (BARO) Sensor Performance

CONDITIONS FOR RUNNING THE DTC
- DTCs P0068, P0101, P0102, P0103, P0107, P0108, P0122, P0123, P0222, P0223, P0506, P0507, P2101, P2108, P2119, P2122, P2123, P2127, P2128, P2135, P2138, or P2176 are not set.
- The engine speed is between 600-6,300 RPM.
- DTC P0106 runs on a 25 millisecond loop.
- DTC P0106 runs continuously once the above conditions are met.

CONDITIONS FOR SETTING THE DTC
The ECM detects that the MAP sensor pressure is not within a calibrated limit of the estimated value for more than 3 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.

TEST DESCRIPTION

Step 1 - Step 7:

Step 8 - Step 16:

Step 17 - Step 23:

Step 24 - Step 31:

The numbers below refer to the step numbers on the diagnostic table.
5. This step tests the ability of the MAP sensor to correctly indicate BARO.
14. The measurement noted in this step will be used in subsequent steps if the measurement does not exceed the specified value.
17. This step calculates the resistance in the 5-Volt reference circuit.
18. This step calculates the resistance in the low reference circuit.