Circuit Description
The manifold absolute pressure (MAP) sensor responds to changes in intake manifold pressure. The PCM supplies a 5 volt reference and a ground for the MAP sensor. The MAP sensor provides a signal to the PCM relative to the pressure changes in the manifold. With low manifold absolute pressure (high vacuum such as during idle or deceleration), the PCM should detect a low MAP sensor signal voltage. With high manifold absolute pressure (low vacuum such as key ON, engine OFF or wide-open throttle), the PCM should detect a high MAP sensor signal voltage. The PCM monitors the MAP signals for voltages outside the normal range of the MAP sensor. If the PCM detects a MAP sensor voltage that is excessively high, DTC P0108 will set.
Conditions for Running the DTC
| • | TP sensor DTCs are not set. |
| • | Engine Speed is more than 1000 RPM. |
| • | Throttle angle is less than 90 percent when engine speed is less than 1000 RPM. |
| • | Throttle angle is less than 97 percent when engine speed in more than 1000 RPM. |
Conditions for Setting the DTC
| • | The MAP sensor signal voltage is more than 4.9 volts. |
| • | The condition exists for less than 1 second. |
Action Taken When the DTC Sets
| • | The PCM illuminates the malfunction indicator lamp (MIL) during the second consecutive trip in which the diagnostic test runs and fails. |
| • | The PCM stores the conditions present when the DTC set as Freeze Frame/Failure Records data. |
Conditions for Clearing the MIL/DTC
| • | The PCM will turn the MIL OFF after the third consecutive trip in which the diagnostic runs and passes. |
| • | The history DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction. |
| • | The DTC can be cleared by using the scan tool Clear DTC Information function. |
Diagnostic Aids
For intermittent conditions, refer to DTC P1106 Manifold Absolute Pressure (MAP) Sensor Circuit Intermittent High Voltage and/or Symptoms .
Step | Action | Values | Yes | No |
|---|---|---|---|---|
1 | Did you perform the Powertrain On Board Diagnostic (OBD) System Check? | -- | ||
2 | Is DTC P1635 also set? | -- | ||
3 |
Does the scan tool indicate a MAP sensor voltage more than the specified value? | 4.4V | ||
4 |
Does the scan tool indicate that DTC P0108 failed last test? | -- | Go to Diagnostic Aids | |
5 |
Does the scan tool display a MAP sensor voltage near the specified value? | 0V | ||
6 |
Did you find and correct the condition? | -- | ||
7 | Replace the MAP sensor. Refer to Manifold Absolute Pressure Sensor Replacement . Is the action complete? | -- | -- | |
8 |
Important: The replacement PCM must be programmed. Replace the PCM. Refer to Powertrain Control Module Replacement/Programming . Is the action complete? | -- | -- | |
9 |
Does the scan tool indicate that DTC P0108 passed? | -- | System OK |
