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 three circuits. The powertrain control module (PCM) supplies a regulated 5 volts to the sensor on a 5-volt reference circuit. The PCM supplies a ground on a low reference circuit. The MAP sensor provides a signal voltage to the PCM, relative to the pressure changes on the MAP sensor signal circuit.

Under normal operation, the highest pressure that can exist in the intake manifold is equal to the 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 PCM uses the MAP sensor to determine the current BARO. The lowest manifold pressures occur when the vehicle is idling or decelerating. The MAP can range from 10 kPa when pressures are low to as much as 105 kPa when pressures are high, depending on the BARO.

Within the PCM, the intake flow rationality diagnostic has the ability to determine an inaccurate input from the three systems it monitors. Calibrated within the diagnostic are estimates for the MAP, the mass air flow (MAF), and the throttle position (TP) for 811 engine operating conditions. The diagnostic compares the estimated values to the actual sensor inputs. If the PCM detects that the MAP sensor input is not within a calibrated limit of the estimated value, DTC P0106 sets.

CONDITIONS FOR RUNNING THE DTC
- DTC P0102, P0103, P0107, P0108, P0112, P0113, P0117, P0118, P0335, P0403, P0405 are not set.
- The change in engine speed is less than 50 RPM.
- The engine speed is between 500-6,700 RPM.
- The engine coolant temperature (ECT) is between 70-121°C (158-250°F).
- The intake air temperature (IAT) is between 70 to +60°C (19-140°F).

CONDITIONS FOR SETTING THE DTC
The PCM detects that the MAP sensor voltage is not within the calibrated limit of the estimated value for more than 1 second.

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

Steps 1-6:

Steps 7-15:

Steps 16-22:

Steps 23-31:

The numbers below refer to the step numbers on the diagnostic table.
4. 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.