Important: The scan tool MAP sensor pressure parameter freezes when a DTC setting fault occurs. The pressure parameter remains fixed until the DTC is cleared and the fault no longer exists.

The manifold absolute pressure (MAP) sensor responds to pressure changes in the intake manifold. The pressure changes occur based on the engine load. The engine control module (ECM) supplies 5 volts to the MAP sensor on the 5-volt reference circuit. The ECM provides a ground on the low reference circuit. The MAP sensor provides a signal to the ECM on the MAP sensor signal circuit which is relative to the pressure changes in the manifold. The ECM detects a low signal voltage at a low MAP, such as during an idle or a deceleration. The ECM detects a high signal voltage at a high MAP, such as the ignition is ON, with the engine OFF, or at a wide open throttle (WOT). The MAP sensor is also used to determine the barometric pressure (BARO). This occurs when the ignition switch is turned ON, with the engine OFF. The BARO reading may also be updated whenever the throttle position (TP) sensor is greater than 28 percent.

The ECM detects that the actual MAP signal is not within the predicted range for greater than 2 seconds.

DTC P0106 is a Type B DTC.

DTC P0106 is a Type B DTC.

With the ignition ON and the engine stopped, the manifold pressure is equal to atmospheric pressure and the signal voltage will be high. This information is used by the ECM as an indication of vehicle altitude. Comparison of this reading with a known good vehicle with the same sensor is a good way to check the accuracy of a suspect sensor. Readings should be the same +0.4 volt.

The MAP sensor vacuum source should be thoroughly inspected for restrictions at the intake manifold.

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Electrical Information Reference

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Special Tools Required

J 23738-A Hand Vacuum Pump

1. Ignition ON, observe the DTC information with a scan tool. Verify DTCs P0642 or P0643 are not set.

⇒	If DTC P0642 or P0643 is set, refer to DTC P0642, P0643, P0698, or P0699 .

2. Engine idling, observe the scan tool MAP Sensor parameters. The reading should be between 30-42 kPa/1.1-1.2 volts.

Important: The vehicle used for the comparison is not limited to the same type of vehicle being serviced. A vehicle known to provide an accurate reading is acceptable.

3. Ignition ON, engine OFF, compare the MAP sensor pressure parameter to the pressure parameter of a known good vehicle. The reading should be within 3 kPa of the known good vehicle.

Important: The Altitude vs Barometric Pressure table indicates a pressure range for a given altitude under normal weather conditions. Weather conditions consisting of very low or very high pressure and/or very low or very high temperature may cause a reading to be slightly out of range.

4. Ignition ON, engine OFF, compare the scan tool MAP sensor pressure parameter to the reading in the Altitude Versus Barometric Pressure . The reading should be within the specified range indicated on the table.
5. Start the engine, the scan tool MAP sensor parameters should change while starting the engine.
6. Engine idling, snap the throttle while observing the scan tool MAP sensor parameters. The reading should change rapidly when the throttle position changes.
7. If the vehicle passes the Circuit/System Verification test, then operate the vehicle within the conditions for running the DTC. You may also operate the vehicle within the conditions that are captured in the Freeze Frame/Failure Records Data List.

1. Verify that none of the following conditions exist:

•	Vacuum leaks or restrictions at the MAP sensor.

•	Engine vacuum leaks

•	Restricted exhaust--Refer to Restricted Exhaust .

•	Worn piston rings--Refer to Engine Compression Test .

2. Ignition OFF, disconnect the harness connector of the MAP sensor.
3. Ignition ON, test for less than 0.2 volt between the low reference circuit and ground.

⇒	If greater than the specified value, test the low reference circuit for a short to voltage. If the circuit tests normal, replace the ECM.

4. Ignition OFF for at least 20 seconds, test for less than 5 ohms of resistance between the low reference circuit and ground.

⇒	If greater than the specified value, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the ECM.

Important: The 5-volt reference circuits are internally and externally connected at the ECM. Other component DTCs may be set. If other DTCs are set, review the electrical schematic and diagnose the applicable circuits and components.

5. Ignition ON, test for 4.8-5.2 volts between the 5-volt reference circuit and ground.

⇒	If less than the specified range, test the 5-volt reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the ECM.

⇒	If greater than the specified range, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the ECM.

6. Verify the scan tool MAP sensor voltage is less than 0.1 volts.

⇒	If greater than the specified value, test the signal circuit for a short to voltage. If the circuit tests normal, replace the ECM.

7. Install a 3A fused jumper wire between the signal circuit and the 5-volt reference circuit. Verify the scan tool MAP sensor voltage is 4.9-5.2 volts.

⇒	If less than the specified range, test the signal circuit for high resistance. If the circuit tests normal, replace the ECM.

8. If all circuits test normal, test or replace the MAP sensor.

1. Ignition OFF, perform one of the following applicable procedures.

•	Disconnect the vacuum supply hose from the MAP sensor

•	Remove the MAP sensor from the intake manifold

2. Ignition ON, observe and record the scan tool MAP sensor pressure data parameter. This is the first MAP sensor reading.
3. With the J 23738-A apply 5 in Hg (17 kPa) of vacuum to the MAP sensor. Observe and record the scan tool MAP sensor pressure data parameter. This is the second MAP sensor reading.
4. Subtract the second MAP sensor reading from the first MAP sensor reading. Verify that the vacuum decrease is within 1 in Hg (4 kPa) of the applied vacuum.

⇒	If the vacuum decrease is not within the specified range, replace the MAP sensor.

5. With the J 23738-A apply 10 in Hg (34 kPa) of vacuum to the MAP sensor. Observe and record the scan tool MAP sensor pressure data parameter. This is the third MAP sensor reading.
6. Subtract the third MAP sensor reading from the first MAP sensor reading. Verify that the vacuum decrease is within 1 in Hg (4 kPa) of the applied vacuum.

⇒	If the vacuum is not with in the specified range, replace the MAP sensor.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.