P0108

Diagnostic Chart (Part 1 Of 2):

Diagnostic Chart (Part 2 Of 2):

Schematic:

CIRCUIT DESCRIPTION
The Manifold Absolute Pressure (MAP) sensor is a pressure sensor. The control module supplies the MAP sensor a reference voltage, signal, and ground circuits. When manifold vacuum is low, the MAP sensor signal voltage rises to a value near the reference voltage, and the MAP sensor signal voltage decreases when the manifold vacuum increases. The control module monitors the MAP sensor signal circuit voltage in order to calculate the vacuum within the intake manifold.

Certain vehicle models will also use the MAP sensor in order to calculate the Barometric Pressure (BARO) when the ignition switch is turned ON and the engine is NOT cranked. This BARO reading may also be updated whenever the engine is operated at Wide Open Throttle (WOT).

This DTC is designed to detect MAP sensor signal voltages higher than possible in a normally operating MAP sensor.

CONDITIONS FOR RUNNING THE DTC
^ No active TP sensor DTCs
^ The engine is running
^ The throttle position is less than 0.4 percent with an engine speed below 1200 RPM

or

The throttle position is less than 20 percent with an engine speed above 1200 RPM

CONDITIONS FOR SETTING THE DTC
The MAP voltage is above 4.4 volts for more than 1 second.

ACTION TAKEN WHEN THE DTC SETS
^ The control module illuminates the Malfunction Indicator Lamp (MIL) if a failure is detected during 2 consecutive key cycles.
^ The control module sets the DTC and records the operating conditions at the time the diagnostic failed. The failure information is stored in the scan tool Freeze Frame and Failure Records.

CONDITIONS FOR CLEARING THE MIL OR DTC
^ The control module turns OFF the MIL after 3 consecutive drive trips when the test has run and passed.
^ A history DTC will clear if no fault conditions have been detected for 40 warm-up cycles. A warm-up cycle occurs when the coolant temperature has risen 22°C (40°F) from the startup coolant temperature and the engine coolant reaches a temperature that is more than 70°C (158°F) during the same ignition cycle.
^ Use a scan tool in order to clear the DTCs.

DIAGNOSTIC AIDS
An intermittent ground in the MAP sensor signal circuit or the 5 volt reference circuit could result in other DTCs. Also an intermittent short to voltage in the 5 volt reference circuit could result in other DTCs.

With the ignition ON and the engine OFF, the manifold pressure is equal to atmospheric pressure with the signal voltage high. The VCM uses this information as an indication of the vehicles altitude. Comparison of this reading with a known good vehicle using the same sensor is a good way to check accuracy of a suspect sensor. Readings should be the same kPa. Refer to Symptoms. Symptom Related Diagnostic Procedures

IMPORTANT: After removing the MAP sensor from the intake manifold, replace the MAP sensor to the intake manifold seal.

An intermittent may be caused by any of the following conditions:
^ A poor connection
^ Rubbed through wire insulation
^ A broken wire inside the insulation

Thoroughly inspect any circuitry that is suspected of causing the intermittent complaint. Refer to Testing for Intermittent and Poor Connections in Diagrams.

If a repair is necessary, refer to Wiring Repairs or Connector Repairs in Diagrams.

TEST DESCRIPTION
The numbers below refer to the step numbers on the diagnostic table.

IMPORTANT: Be sure to use the same diagnostic equipment for all measurements.

3. Disconnecting the MAP sensor harness could set other MAP related DTCs.
4. This step checks for a stuck TP sensor which could set a MAP sensor code. Even though DTC P0102 did not set, this DTC is more comprehensive and may aid in diagnosis.
5. Even though DTC P0102 did not set, this DTC is more comprehensive and may aid in diagnosis.
7. This step checks for a short to voltage on the 5 volt reference circuit.
8. This step checks the integrity of the MAP sensor ground circuit.
11. The VCM terminals C3 12 and C3 27 are spliced together inside the VCM. When checking the 5 volt reference for a short to ground, both the 5 volt reference circuits and all of the components on the 5 volt reference circuits must also be checked.