Buick Regal: DTC P0106

Diagnostic Instructions

• Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
• Review Strategy Based Diagnosis for an overview of the diagnostic approach.
• Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptor

DTC P0106

Manifold Absolute Pressure (MAP) Sensor Performance

Diagnostic Fault Information

Typical Scan Tool Data

MAP Sensor

MAP Sensor, if equipped with Turbocharger

Circuit Description

The manifold absolute pressure (MAP) sensor measures the pressure inside the intake manifold.

Pressure in the intake manifold is affected by engine speed, throttle opening, air temperature, barometric pressure (BARO) and if equipped, turbocharger output. A diaphragm within the MAP sensor is displaced by the pressure changes that occur from the varying load and operating conditions of the engine. The sensor translates this action into electrical resistance.

The MAP sensor wiring includes 3 circuits. The engine control module (ECM) supplies a regulated 5 volts to the sensor on a 5 V reference circuit. The ECM supplies a ground on a low reference circuit. The MAP sensor provides a signal voltage to the ECM, relative to the pressure changes, on the MAP sensor signal circuit. The ECM converts the signal voltage input to a pressure value.

Under normal operation the greatest pressure that can exist in the intake manifold is at ignition ON, engine OFF, which is equal to the BARO. If equipped, a turbocharger can increase the pressure above BARO, when the vehicle is operated at wide-open throttle (WOT). The lowest manifold pressure occurs when the vehicle is idling or decelerating. The ECM monitors the MAP sensor signal for pressure outside of the normal range.

Conditions for Running the DTC

• DTCs P0102, P0103, P0107, P0108, P0111, P0112, P0113, P0114, P0116, P0117, P0118, P0128, P0335, P0336, P2227, P2228, P2229, and P2230 are not set.
• The engine speed is between 575 and 6, 600 RPM.
• The ECT Sensor is between -7 and +125ºC (+19 and +257ºF).
• The IAT Sensor is between -20 and +125ºC (-4 and +257ºF).
• This DTC runs continuously when the above conditions are met.

Conditions for Setting the DTC

The ECM determines if the MAP Sensor is not within the normal operating range. It accomplishes this by running 3 different models within the software to determine the values, for greater than 0.5 S.

Action Taken When the DTC Sets

DTC P0106 is a Type B DTC.

Conditions for Clearing the MIL/DTC

DTC P0106 is a Type B DTC.

Reference Information

Schematic Reference

Engine Controls Wiring Schematics (LTG)

Connector End View Reference

Component Connector End View Index

Powertrain Component View

Powertrain Component Views

Electrical Information Reference

• Circuit Testing
• Connector Repairs
• Testing for Intermittent Conditions and Poor Connections
• Wiring Repairs

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Special Tools

GE-23738-A Vacuum Pump

For equivalent regional tools, refer to Special Tools (diagnostic tools) and Special Tools (Mechanical Tools).

Circuit/System Verification

1. Ignition ON.

2. Verify that DTC P0641, P0651, P0697, P06A3, or P06D2 is not set.

• If any of the DTCs are set

Refer to Diagnostic Trouble Code (DTC) List - Vehicle for further diagnosis.

• Go to next step: If none of the DTCs are set

3. If you were sent here from DTC P0068, P0101, P0121, P0236, or P1101 refer to Circuit/System Testing.

4. Verify the scan tool Throttle Body Idle Airflow Compensation parameter is less than 90%.

• If 90% or greater

Refer to Throttle Body Cleaning.

• Go to next step: If less than 90%

5. Verify the scan tool Throttle Body Sensors 1 and 2 Agree/Disagree parameter displays Agree while performing the Throttle Sweep Test with a scan tool.

• If Disagree

Refer to DTC P0121-P0123, P0222, P0223, P16A0-P16A2, or P2135 for further diagnosis.

• Go to next step: If Agree

6. Determine the current vehicle testing altitude.

7. Verify the scan tool MAP Sensor pressure parameter is within the range specified in the Altitude Versus Barometric Pressure table.

• If the MAP Sensor parameter is not in range

Refer to Circuit/System Testing.

• Go to next step: If the MAP Sensor parameter is in range

8. Verify if the engine is equipped with a turbocharger.

• If not equipped with a turbocharger

Refer to Step 12.

• Go to next step: If equipped with a turbocharger

9. Verify the scan tool Boost Pressure Sensor parameter is within the range specified in the Altitude Versus Barometric Pressure table.

• If the Boost Pressure Sensor parameter is not in range

Refer to DTC P0236 for further diagnosis.

• Go to next step: If the Boost Pressure Sensor parameter is within range

10. Verify the scan tool Boost Pressure Sensor parameter decreases after starting the engine.

• If the Boost Pressure Sensor parameter does not decrease

Refer to DTC P0236 for further diagnosis.

• Go to next step: If the Boost Pressure Sensor parameter does decrease

11. Engine idling.

12. Verify the scan tool MAP Sensor pressure parameter is between 26 - 52 kPa (3.8 - 7.5 PSI) and changes with accelerator pedal input.

• If not between 26 - 52 kPa (3.8 - 7.5 PSI) or does not change

Refer to Circuit/System Testing.

• Go to next step: If between 26 - 52 kPa (3.8 - 7.5 PSI) and changes

13. Verify the scan tool MAF Sensor g/s parameter changes smoothly and gradually as the engine speed is increased and decreased while performing the actions listed below.

1. Engine idling
2. Perform the scan tool snapshot function.
3. Increase the engine speed slowly to 3000 RPM and then back to idle.
4. Exit from the scan tool snapshot and review the data.
5. Observe the MAF Sensor parameter frame by frame with a scan tool.

• The MAF Sensor parameter does not change smoothly and gradually

Refer to DTC P0101 for further diagnosis.

• Go to next step: The MAF Sensor parameter changes smoothly and gradually

14. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

15. Verify a DTC does not set.

• If the DTC sets

Refer to Circuit/System Testing.

• Go to next step: If the DTC does not set

16. All OK.

Circuit/System Testing

1. Verify the integrity of the entire air induction system and verify that none of the following conditions exist:

• Any damaged components
• Improper operation of turbocharger wastegate actuator or bypass valve; if equipped
• Loose or improper installation of the turbocharger and the charge air cooler, including the flexible ductwork; if equipped
• An air flow restriction
• Any vacuum leak
• Improperly routed vacuum hoses
• A restriction in the MAP Sensor port, or the BARO port; where equipped
• Proper operation of the positive crankcase ventilation system
• Missing, restricted or leaking exhaust components. Refer to Symptoms - Engine Exhaust.
• Engine mechanical condition; for example: low compression or incorrect timing chain installation. Refer to Symptoms - Engine Mechanical.
• If a condition is found

If a condition is found, repair or replace the component as appropriate.

• Go to next step: If no condition is found

2. Ignition OFF and all vehicle systems OFF. It may take up to 2 min for all vehicle systems to power down. Disconnect the harness connector at the B74 Manifold Absolute Pressure Sensor.

3. Test for less than 2 Ω between the low reference circuit terminal 2 and ground.

If 2 Ω or greater

1. Ignition OFF, disconnect the harness connector at the K20 Engine Control Module.
2. Test for less than 2 Ω in the low reference circuit end to end.
   • If 2 Ω or greater, repair the open/high resistance in the circuit.
   • If less than 2 Ω, replace the K20 Engine Control Module.

Go to next step: If less than 2 Ω

4. Ignition ON.

5. test for 4.8 - 5.2 V between the 5 V reference circuit terminal 1 and ground.

• If less than 4.8 V

1. Ignition OFF, disconnect the harness connector at the K20 Engine Control Module.
2. Test for infinite resistance between the 5 V reference circuit and ground.
   • If less than infinite resistance, repair the short to ground on the circuit.
   • Go to next step: If infinite resistance
3. Test for less than 2 Ω in the 5 V reference circuit end to end.
   • If 2 Ω or greater, repair the open/high resistance in the circuit.
   • If less than 2 Ω, replace the K20 Engine Control Module.

NOTE: If the signal circuit is shorted to a voltage the ECM or the MAP Sensor may be damaged.

• If greater than 5.2 V

1. Ignition OFF, disconnect the harness connector at the K20 Engine Control Module.
2. Ignition ON, test for less than 1 V between the 5 V reference circuit and ground.
   • If 1 V or greater, repair the short to voltage on the circuit.
   • If less than 1 V, replace the K20 Engine Control Module.

• Go to next step: If between 4.8 - 5.2 V

6. Verify the scan tool MAP Sensor parameter is less than 0.5 V.

• If 0.5 V or greater

1. Ignition OFF, disconnect the harness connector at the K20 Engine Control Module, ignition ON
2. Test for less than 1 V between the signal circuit terminal 3 and ground.
   • If 1 V or greater, repair the short to voltage on the circuit.
   • If less than 1 V, replace the K20 Engine Control Module.

• Go to next step: If less than 0.5 V

7. Install a 3 A fused jumper wire between the signal circuit terminal 3 and the 5 V reference circuit terminal 1.

8. Ignition ON, verify the scan tool MAP voltage parameter is greater than 4.5 V.

• If 4.5 V or less

1. Ignition OFF, disconnect the harness connector at the K20 Engine Control Module.
2. Test for infinite resistance between the signal circuit terminal 3 and ground.
   • If less than infinite resistance, repair the short to ground on the circuit.
   • Go to next step: If infinite resistance
3. Test for less than 2 Ω in the signal circuit end to end.
   • If 2 Ω or greater, repair the open or high resistance in the circuit.
   • If less than 2 Ω, replace the K20 Engine Control Module.

• Go to next step: If greater than 4.5 V

9. Test or replace the B74 Manifold Absolute Pressure Sensor.

Component Testing

NOTE: You must perform the Circuit/System Testing in order to verify the integrity of the MAP Sensor circuits before proceeding with the Component Testing.

Skewed Sensor Test

1. Ignition OFF, remove the B74 Manifold Absolute Pressure Sensor from the engine. Connect the harness to the sensor, if disconnected.

2. Ignition ON.

3. Apply 17 kPa (5.0 in Hg) of vacuum to the B74 Manifold Absolute Pressure Sensor, with the GE- 23738-A.

4. Verify the scan tool MAP pressure parameter decreases between 13 - 21 kPa (1.8 - 3.0 PSI).

• If the parameter does not decrease between 13 - 21 kPa (1.8 - 3.0 PSI).

Replace the B74 Manifold Absolute Pressure Sensor.

• Go to next step: If the parameter does decrease between 13 - 21 kPa (1.8 - 3.0 PSI).

5. Apply 34 kPa (10.0 in Hg) of vacuum to the B74 Manifold Absolute Pressure Sensor, with the GE-23738-A.

6. Verify the scan tool MAP pressure parameter decreases between 30 - 38 kPa (4.4 - 5.5 PSI).

• If the parameter does not decrease between 30 - 38 kPa (4.4 - 5.5 PSI).

Replace the B74 Manifold Absolute Pressure Sensor.

• Go to next step: If the parameter does decrease between 30 - 38 kPa (4.4 - 5.5 PSI).

7. All OK.

Erratic Signal Test

1. Ignition OFF, remove the B74 Manifold Absolute Pressure Sensor and disconnect the harness.

2. Install a 3 A fused jumper wire between the 5 V reference circuit terminal 1 of the sensor and the sensor harness.

3. Install a jumper wire between the low reference circuit terminal 2 of the sensor and ground.

4. Install a jumper wire to the signal circuit terminal 3 of the sensor.

5. Connect a DMM between the jumper wire and ground.

6. Ignition ON, observe the DC voltage on the DMM. Slowly apply between 0 - 15 kPa (0 - 4.4 in Hg) of vacuum to the sensor with the GE-23738-A.

7. Verify the voltage changes, without any spikes or dropouts and is between 0.2 - 4.9 V.

• If not between 0.2 - 4.9 V or has spikes or dropouts

Replace the B74 Manifold Absolute Pressure Sensor.

• Go to next step: If between 0.2 - 4.9 V and there are no spikes or dropouts

8. All OK.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.

• Control Module References for ECM replacement, programming, and setup
• Manifold Absolute Pressure Sensor Replacement.

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