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 VCM on the 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 TP Sensor DTCs are set

^ Throttle Position is no more than 0.4% when engine speed is no more than 1200 RPM

^ Or the Throttle Position is no more than 19.9% when engine speed is greater than 1200 RPM

^ MAP is greater than 4.34 v

ACTION TAKEN WHEN THE DTC SETS

The VCM turns the 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 startup 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

IMPORTANT: The electrical connector must remain securely fastened.

IMPORTANT: Disconnect the sensor from the bracket and twist the sensor by hand (only) in order to check for intermittent connections. The output changes greater than 0.1 volt indicates a bad connector or connection. If OK, replace the sensor.

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

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 GRi2 and GR27 are spliced together inside the VCM. This step isolates the two pins from one another.