P0108

Diagnostic Chart (Part 1 Of 2):

Diagnostic Chart (Part 2 Of 2):

Engine Controls Schematics: A/C Pressure Switch, TPS, MAP, ECT and IAT:

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, or the vacuum is high, sensor output voltage is low. When manifold pressure is high, or the vacuum is low, sensor output voltage is high. MAP sensor voltage, depending on altitude, can range from below 2 volts at idle to above 4 volts at Wide Open Throttle (WOT) or with the engine not running.

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 are present.
^ The engine has been running for a length of time that is determined by start-up 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).
^ The idle speed is steady.
^ The throttle position below 2 percent.
^ The engine speed is less than 3000 RPM.

CONDITIONS FOR SETTING THE DTC
^ The MAP sensor signal voltage is more 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 (MIL) 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 during which the diagnostic runs and passes.
^ A last test failed, or the current DTC, clears when the diagnostic runs and passes.
^ A History DTC clears after forty consecutive warm-up cycles, if no other emission related diagnostic failures are reported.
^ Use a scan tool in order to clear the MIL diagnostic trouble code.
^ Interrupting the PCM battery voltage may or may not clear DTCs. This practice is not recommended. Refer to Powertrain Control Module (PCM) Description, Clearing Diagnostic Trouble Codes.

DIAGNOSTIC AIDS

NOTE: Refer to Connector Test Adapter kit J 35616-A Notice in Service Precautions.

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.

If the problem is intermittent, refer to Intermittent Conditions. Intermittent Conditions

TEST DESCRIPTION
Numbers below refer to the step numbers on the diagnostic table:
11. This vehicle is equipped with a PCM that utilizes an Electrically Erasable Programmable Read Only Memory (EEPROM). When the PCM is being replaced, the new PCM must be programmed.