GM Service Manual Online
For 1990-2009 cars only

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

Circuit

Short to Ground

High Resistance

Open

Short to Voltage

Signal Performance

5-Volt Reference

P0107, P0641, P2229

P0106

P0107

P0106, P0641, P2228

P0106, P1101

MAP Sensor Signal

P0107

P0106

P0107

P0108

P0106, P1101

Low Reference

--

P0106, P0108

P0106, P0108

--

P0106, P1101

Typical Scan Tool Data

MAP Sensor

Circuit

Short to Ground

Open

Short to Voltage

Operating Conditions: Engine running at various operating conditions

Normal Parameter Range: 37-165 kPa

5-Volt Reference

12 kPa

12 kPa

200-210 kPa

MAP Sensor Signal

12 kPa

12 kPa

200-210 kPa

Low Reference

--

200-210 kPa

--

Circuit Description

Important: The following applies to the intake airflow system performance diagnostic that is used in this supercharged engine:

   • When referring to the supercharger intake manifold models, the plenum volume between the throttle body and the supercharger is considered to be the intake manifold.
   • When referring to engine pumping, the supercharger and the intercooler plenum are considered to be part of the engine.
   • The manifold absolute pressure (MAP) estimates are used in the engine air flow estimates. Air flow into the intake system must be the same as the air flow out of the intake system, the Intake Airflow Rationality Diagnostics (IFRD) calculates air flowing out of the engine based on MAP estimates, volumetric efficiency, and RPM.

The intake airflow system performance diagnostic provides the within-range rationality check for the mass air flow (MAF), supercharger inlet absolute pressure (SCIAP), MAP, by-pass valve stuck, and the throttle position (TP) sensors. This is an explicit model-based diagnostic containing 4 separate models for the intake system.

    • The throttle model describes the flow through the throttle body and is used to estimate the MAF through the throttle body as a function of barometric pressure (BARO), throttle position, intake air temperature (IAT), and estimated SCIAP. The information from this model is displayed on the scan tool as the MAF Performance Test parameter.
    • The first supercharger intake manifold model describes the pressure at the supercharger intake manifold and is used to estimate SCIAP as a function of the MAF into the intake manifold from the throttle body and the MAF out of the intake manifold caused by engine pumping. The flow into the supercharger intake manifold from the throttle uses the MAF estimate calculated from the above throttle model. The information from this model is displayed on the scan tool as the MAP Performance Test 1 parameter.
    • The second supercharger intake manifold model is identical to the first supercharger intake manifold model except that the MAF sensor measurement is used instead of the throttle model estimate for the throttle air input. The information from this model is displayed on the scan tool as the MAP Performance Test 2 parameter.
    • A fourth model is created from the combination and additional calculations of the throttle model and the first supercharger intake manifold model. The information from this model is displayed on the scan tool as the TP Performance Test parameter.
    • In addition 5 new models have been added, these models run in the background.

The estimates of MAF, SCIAP, and TP that are obtained from this system of models and calculations are then compared to the actual measured values from the MAF, SCIAP, and the TP sensors and to each other to determine the appropriate DTC to fail. The following table illustrates the possible failure combinations and the resulting DTC or DTCs.

Scan Tool Diagnostic Test Results

MAF Performance Test

MAP Performance Test 1

MAP Performance Test 2

TP Performance Test

DTCs Passed

DTCs Failed

--

--

OK

OK

P0101, P0121, P012B, P1101

None

OK

OK

Fault

OK

P0101, P0121, P012B, P1101

None

Fault

OK

Fault

OK

P0121, P012B, P1101

P0101

OK

Fault

Fault

OK

P0101, P0121

P012B

Fault

Fault

Fault

OK

P0121, P1101

P0101

P012B

--

--

OK

Fault

P0101, P012B, P1101

P0121

OK

OK

Fault

Fault

P0101, P0121, P012B, P1101

None

Fault

OK

Fault

Fault

P0101, P0121, P012B, P1101

P0101, P1101

--

Fault

Fault

Fault

P0101, P0121, P012B

P0101, P1101

Conditions for Running the DTC

    • DTCs P0069, P0096, P0097, P0098, P0102, P0103, P0107, P0108, P0111, P0112, P0113, P0116, P0117, P0118, P0120, P0121, P0128, P012C, P012D, P0220, P0335, P0336, P0401, P0405, P0506, P0507, P1404, P2135, P2228, or P2229 are not set.
    • The engine speed is running.
    • The engine coolant temperature (ECT) sensor is between 70-129°C (158-264°F).
    • The intake air temperature (IAT) sensor is between -7 to +60°C (+19 to +140°F).
    • This DTC runs continuously when the above enabling conditions are met.

Conditions for Setting the DTC

    • The ECM detects that the MAP sensor signal is 25 kPa greater than the calibrated threshold for greater than 90 seconds.
        OR
    • The ECM detects that the MAP sensor signal is 45 kPa less than the calibrated threshold for greater than 90 seconds.

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.

Diagnostic Aids

    • Any condition that can cause the MAF, MAP, SC inlet pressure, and TP sensors to be shifted in value or any condition that may cause the by-pass valve to stick, at the same time may cause this DTC to set.
    • A slight to moderate resistance of 20-50 ohms on the 5-volt reference or low reference circuits may cause this DTC to set.

Caution: Refer to Road Test Caution in the Preface section.

    • Road test the vehicle and verify that the MAF sensor calculated g/s and the actual MAF g/s parameters are near or equal to each other.
    • A steady or intermittent high resistance of 15 ohms or more on the 5-volt reference circuit will cause the MAP sensor values to be skewed.
    • A skewed or stuck ECT, MAF/IAT, or IAT sensor 2 will cause the calculated models to be inaccurate and may cause this DTC to run when it should not. Refer to Temperature Versus Resistance .

Reference Information

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Component Connector End 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

    • J 23738-A Mityvac
    • J 35555 Metal Mityvac

Circuit/System Verification

  1. Verify that DTCs P0641 and P0651 are not set.
  2. If any of the DTCs are set, refer to DTC P0641 or P0651 .
  3. Verify that restrictions do not exist in the exhaust system. Refer to Restricted Exhaust .
  4. Verify that the engine is in good mechanical condition. Refer to Symptoms - Engine Mechanical .
  5. Ignition ON, observe the scan tool MAP, SC Inlet Pressure, and BARO parameters. Verify the MAP, SC Inlet Pressure, and BARO sensor parameters are within 5 kPa of each other.
  6. Ignition ON, observe the MAP Sensor kPa parameter with a scan tool. Start the engine. The MAP Sensor kPa parameter should change.
  7. Engine running at idle, observe and record the MAP Sensor parameter kPa value with a scan tool. Slowly increase the engine speed from idle to 2,000 RPM, then allow the engine speed to return idle. The MAP sensor parameter should increment to a higher value at 2,000 RPM and return to the recorded idle value.
  8. Ignition ON, compare APP sensors 1 and 2 percentages with a scan tool. Verify that they do not differ more than 5 percent while performing a slow pedal sweep is performed.
  9. Ignition ON, observe the scan tool MAP sensor parameter. Start the engine. The MAP Sensor parameter should change.
  10. Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

Circuit/System Testing

  1. Verify the integrity of the entire supercharger air induction system by inspecting for the following conditions:
  2. • Damaged components
    • Loose or improper installation
    • An air flow restriction
    • Any vacuum leak
    • Improperly routed vacuum hoses
    • In cold climates, inspect for any snow or ice buildup.
    • Verify that restrictions do not exist in the MAP sensor port or vacuum source.
  3. Ignition OFF, disconnect the harness connector at the MAP sensor.
  4. Ignition OFF for 90 seconds, test for less than 5 ohms between the low reference circuit terminal A and ground.
  5. If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the ECM.
  6. Ignition ON, test for 4.8-5.2 volts between the 5-volt reference circuit terminal C and ground.
  7. 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.
  8. Verify the scan tool MAP parameter is less than 15 kPa.
  9. If greater than the specified range, test the signal circuit terminal B for a short to voltage. If the circuit tests normal, replace the ECM.
  10. Install a 3A fused jumper wire between the signal circuit terminal B and the 5-volt reference terminal C. Verify the scan tool MAP parameter is greater than 200 kPa.
  11. If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the ECM.
  12. If all circuits test normal, test or replace the MAP sensor.

Component Test

Important: 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 Signal Test

  1. Using the following steps and referencing the table below will determine if the MAP sensor is skewed.
  2. Ignition ON, engine OFF, observe the MAP sensor scan tool parameter.
  3. Use the observed MAP Sensor Scan Tool parameter that is closest to a value that is indicated in the first column.
  4. THEN

  5. Using the J 23738-A or the J 35555 to apply 5 in Hg of vacuum to the MAP sensor, the parameter in the first column should decrease by 17 kPa. The acceptable range is indicated in the second column.
  6. Using the J 23738-A or the J 35555 to apply 10 in Hg of vacuum to the MAP sensor, the parameter in the first column should decrease by 34 kPa. The acceptable range is indicated in the third column.

Ignition ON, Engine OFF, MAP Sensor Parameter

MAP Sensor Parameter With 5 Inches of Vacuum Applied

MAP Sensor Parameter With 10 Inches of Vacuum Applied

100 kPa

79-87 kPa

62-70 kPa

95 kPa

74-82 kPa

57-65 kPa

90 kPa

69-77 kPa

52-60 kPa

80 kPa

59-67 kPa

42-50 kPa

70 kPa

49-57 kPa

32-40 kPa

60 kPa

39-47 kPa

22-30 kPa

Erratic Signal Test

  1. Ignition OFF, remove the MAP sensor.
  2. Install a 3A fused jumper wire between the 5-volt reference circuit terminal C and the corresponding terminal of the MAP sensor.
  3. Install a jumper wire between the low reference circuit terminal A of the MAP sensor and ground.
  4. Install a jumper wire at terminal B of the MAP sensor.
  5. Connect a DMM between the jumper wire from terminal B of the MAP sensor and ground.
  6. Ignition ON, with the J 23738-A or J 35555 , slowly apply vacuum to the sensor while observing the voltage on the DMM. The voltage should vary between 4.9-0.04 volts, without any spikes or dropouts.
  7. If the voltage reading is erratic, replace the MAP sensor.

Repair Instructions

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

Repair Verification

  1. Ignition ON, observe the MAP, SC Inlet Pressure, and BARO parameters with a scan tool. The MAP, SC Inlet Pressure, and BARO sensor parameters should be within 5 kPa of each other.
  2. With a scan tool, command the supercharger bypass control valve ON. Slowly increase the engine speed from idle to 2,000 RPM and return the engine to idle speed. The MAP sensor parameter should increment to a higher value and return to the normal idle value.