P0108

Circuit Description
The Manifold Absolute Pressure (MAP) sensor is mounted to the top of the intake manifold. The MAP sensor measures pressure changes within the intake manifold which are an indication of engine load. The MAP sensor has a 5.0 volt reference, a ground and a signal circuit.

The MAP sensor contains a diaphragm which changes resistance based on pressure. When manifold pressure is low (high vacuum) sensor output voltage is low. When manifold pressure is high (low vacuum) sensor output voltage is high. MAP sensor voltage (depending on altitude) can range from below 2 volts at idle (high vacuum) to above 4 volts at wide open Throttle, or with the engine not running (low vacuum).

The MAP sensor signal is also used at initial key-up to determine barometric pressure (BARO).

Conditions for Running the DTC
^ No TP sensor DTCs present.
^ Engine has been running for a length Of time that is determined by startup coolant temperature. The length of time ranges from 2 minutes at less than -30°C(-22°F) to 0.5 second at more than 30°C(86°F).
^ Idle speed is steady.
^ Throttle position below 2%.
^ Engine speed is less than 3000 RPM.

Conditions for Setting the DTC
^ The MAP sensor signal voltage is greater than 4.2 volts.
^ The above conditions are present for approximately 10 seconds.

Action Taken When the DTC Sets
^ The PCM illuminates the Malfunction Indicator Lamp on the second consecutive ignition cycle that the diagnostic runs and fails.
^ The PCM records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the PCM stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the PCM records the operating conditions at the time of the failure. The PCM writes the conditions to the Freeze Frame and updates the Failure records.

Conditions for Clearing the MIL/DTC
^ The PCM turns the MIL Off after three consecutive drive trips that the diagnostic runs and does not fail.
^ A last test failed (current DTC) clears when the diagnostic runs and does not fail.
^ A History DTC clears after forty consecutive warm-up cycles, if this or any Other emission related diagnostic does not report any failures.
^ Use a scan tool in order to clear the MIL/DTC.
^ Interrupting the PCM battery voltage may or may not clear DTCs. This practice is not recommended.

Diagnostic Aids

Notice: Use the Connector Test Adapter Kit J 35616-A for any test that requires probing the following items:
^ The PCM harness connectors
^ The electrical center fuse/relay cavities
^ The component terminals
^ The component harness connector

Using this kit will prevent damage caused by the improper probing of connector terminals.

If DTC P0108 cannot be duplicated, the information included in the Fail Records data can be useful in determining since the DTC was last set.

Test Description
Number(s) below refer to the step number(s) on the Diagnostic Table:
11. This vehicle is equipped with a PCM which utilizes an Electrically Erasable Programmable Read Only Memory (EEPROM). When the PCM is being replaced, the new PCM must be programmed.