P1106

Diagnostic Chart:

Wiring Diagram:

CIRCUIT DESCRIPTION

The Manifold Absolute Pressure (MAP) sensor responds to changes in the intake manifold pressure (vacuum). A 5 volt reference is applied to the sensor on the 5 volt reference circuit. A variable resistor moves in relation to the manifold pressure and a voltage signal is sent back to the Vehicle Control Module (VCM) on the Manifold Absolute Pressure (MAP) sensor signal circuit. This voltage signal will vary from 1.0-1.5 volts at closed throttle to 4.0-4.6 volts at wide open throttle (low vacuum). The VCM utilizes the MAP signal and the throttle position in order to determine the correct amount of fuel delivered to the engine.

CONDITIONS FOR SETTING THE DTC

The following conditions will set the DTC:

^ No Throttle Position (TP) DTCs.

^ TP is less than or equal to 0.4% when engine speed is less than or equal to 1200 RPM, or the TP is less than or equal to 20% when engine speed is greater than 1200 RPM.

ACTION TAKEN WHEN THE DTC SETS

The VCM turns the Malfunction Indicator Lamp (MIL) ON when this DTC is reported and 1 failure has occurred. The VCM substitutes a calculated value for the MAP sensor value so that acceptable performance is maintained.

CONDITIONS FOR CLEARING THE MIL/DTC

^ A history DTC will clear if no fault conditions have been detected for 40 warm-up cycles (coolant temperature has risen 22°C (40°F) from the start-up coolant temperature and the engine coolant temperature exceeds 70°C (160°F) during the same ignition cycle.

^ Use the scan tool Clear Information function.

^ Disconnect the VCM battery feed for 30 seconds.

DIAGNOSTIC AIDS

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 vehicle's altitude. Comparison of this reading with a known good vehicle using the same sensor is a good way to check the accuracy of a suspect sensor. Readings should be the same ±0.4 volts.

Refer to Symptoms.
Testing and Inspection

NOTICE: The electrical connector must remain securely fastened.

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

Remove the MAP sensor. Twist sensor by hand (only) to check for intermittent connections. Output changes greater than 0.1 volts indicates a bad connector or connection. If OK, replace sensor.

TEST DESCRIPTION

Number(s) below refer to the step number(s) on the Diagnostic Table.

5. This step checks for a short to voltage on the 5 volt reference circuit.

6. This step checks the integrity of the MAP sensor ground circuit.

10. VCM pins CLR 12 and CLR 27 are spliced together inside the VCM. This step isolates the two pins from one another.