P0108

DTC P0108

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 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 TP sensor is more than 28 percent. 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 excessively high, DTC P0108 sets.

DTC DESCRIPTOR
This diagnostic procedure supports the following DTC:
DTC P0108 Manifold Absolute Pressure (MAP) Sensor Circuit 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 15 percent if the engine speed is less than 2,500 RPM.
- The TP sensor is less than 35 percent if the engine speed is more than 2,500 RPM.
- DTC P0108 runs continuously once the above conditions are met.

CONDITIONS FOR SETTING THE DTC
The ECM detects that the MAP is more than 103 kPa for more than 5 seconds.

ACTION TAKEN WHEN THE DTC SETS
- The control module illuminates the malfunction indicator lamp (MIL) when the diagnostic runs and fails.
- The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Freeze Frame/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 1-4:

Steps 5-8:

Steps 9-13:

Steps 14-15:

4. This step determines if there is a short to voltage or an open condition in the circuits.
9. This step determines if the circuit has a short to voltage. A short to voltage can cause more than 1 DTC to set.