• 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.

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.

• DTC P0102, P0103, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0128, P0335 or P0336 is not set.
• The engine speed is between 400–7,000 RPM.
• The intake air temperature (IAT) Sensor parameter is between −20° to +125°C (−4° to +257°F).
• The engine coolant temperature (ECT) Sensor parameter is between 69–127°C (156–260°F).
• This DTC runs continuously when the above conditions are met.

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.

DTC P0106 is a Type B DTC.

DTC P0106 is a Type B DTC.

Engine Controls Schematics

Master Electrical Component List

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

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Control Module References for scan tool information

GE–23738-A Vacuum Pump

For equivalent regional tools, refer to Special Tools.

1. Ignition ON, verify that DTC P0641, P0651, P0697, or P06A3 is not set.
• If any of the DTCs are set

  Refer to DTC P0641, P0651, P0697, or P06A3 for further diagnosis.

• If none of the DTCs are set
2. If you were sent here from DTC P0068, P0101, P0121, or P1101; refer to Circuit/System Testing.
3. Ignition ON, verify the scan tool Throttle Body Idle Airflow Compensation parameter is less than 90%.
• If 90 % or greater

  Refer to Throttle Body Cleaning and Inspection.

• If less than 90 %
4. Verify the scan tool Throttle Position 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.

• If Agree
5. Determine the current vehicle testing altitude.
6. Verify the scan tool MAP Sensor 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.

• If the MAP Sensor parameter is within range
7. Engine idling, 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.

• If between 26–52 kPa (3.8–7.5 PSI) and changes
8. 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.

• The MAF Sensor parameter changes smoothly and gradually
9. 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.
10. Verify a DTC does not set.
• If the DTC sets

  Refer to Circuit/System Testing.

• If the DTC does not set
11. All OK.

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
• In cold climates, inspect for any snow or ice buildup at the BARO port on the ECM, if equipped
• A restriction in the MAP Sensor port or the BARO port
• Proper operation of the Positive Crankcase Ventilation (PCV) 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

  Repair or replace the component as appropriate.

• 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.
• If less than 2 Ω
4. Ignition ON, 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.
• 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.
• If between 4.8–5.2 V
5. Ignition ON, 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.
2. Ignition ON, 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.
• If less than 0.5 V
6. Ignition OFF, install a 3 A fused jumper wire between the signal circuit terminal 3 and the 5 V reference circuit terminal 1.
7. Ignition ON, verify the scan tool MAP Sensor 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. Remove the jumper wire, 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.
• 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.
• If greater than 4.5 V
8. Test or replace the B74 Manifold Absolute Pressure Sensor.

1. Ignition OFF, remove the B74 Manifold Absolute Pressure Sensor from the engine. Connect the harness to the sensor, if disconnected.
2. Ignition ON, apply 17 kPa (5.0 in Hg) of vacuum to the B74 Manifold Absolute Pressure Sensor, with the GE-23738-A . 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.

• If the parameter does decrease between 13–21 kPa (1.8–3.0 PSI).
3. Apply 34 kPa (10.0 in Hg) of vacuum to the B74 Manifold Absolute Pressure Sensor, with the GE-23738-A . 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.

• If the parameter does decrease between 30–38 kPa (4.4–5.5 PSI).
4. All OK.

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, 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.

• If between 0.2–4.9 V and there are no spikes or dropouts
8. All OK.

Perform the Diagnostic Repair Verification after completing the repair

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