For 1990-2009 cars

### 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, P0193, P0236, P0335, P0642 | P0106, P0107 | P0107 | P0193, P0236, P0606, P0643, P0690, P2227 | P0641, P0642, P0643
MAP Sensor Signal | P0107 | P0106, P0107 | P0107 | P0106, P0108 | P0106
Low Reference | -- | P0106 | P0106 | -- | --

### Typical Scan Tool Data

#### MAP Sensor

Circuit | Short to Ground | Open | Short to Voltage
--- | --- | --- | ---
Operating Conditions: Engine running, transmission in Park or Neutral. Parameter Normal Range: 20-48 kPa, varies with altitude.
5-Volt Reference | 0 kPa | 0 kPa | 0-30 kPa
MAP Sensor Signal | 0 kPa | 0 kPa | 255 kPa
Low Reference | -- | 80-250 kPa | --

### Circuit/System Description

The manifold absolute pressure (MAP) sensor has a 5-volt reference circuit, a low reference circuit, and a signal circuit. The engine control module (ECM) supplies 5V to the MAP sensor on the 5-volt reference circuit, and provides a ground on the low reference circuit. The MAP sensor provides a voltage signal to the ECM on the signal circuit relative to the intake manifold pressure changes.

The sensor used on this engine is a three atmosphere sensor. Pressure in the intake manifold is affected by engine speed, throttle opening, turbocharger boost pressure, intake air temperature (IAT), and barometric pressure (BARO). Under normal operation the greatest pressure that can exist in the intake manifold at ignition ON, engine OFF is equal to the BARO. When the vehicle is operated at wide-open throttle (WOT), the turbocharger can increase the pressure to near 240 kPa. The least manifold pressure occurs when the vehicle is decelerating and can range from 13-48 kPa.

The purpose of this diagnostic is to analyze the performance of the MAP sensor by comparing the measured pressure changes to the following 2 distinct models:

• | The engine cranking model uses BARO and boost pressure as inputs

• | The engine running model uses BARO, boost pressure, throttle opening and engine speed as inputs

### Conditions for Running the DTC

#### P0106 - Engine Cranking

• | DTCs P0096, P0097, P0098, P0099, P0107, P0108, P0121, P0122, P0123, P0221, P0222, P0223, P0236, P0237, P0238, P0455, P0496, P2176, P2227, P2228, P2229 are not set.

• | The engine OFF timer is greater than 4 seconds before cranking begins.

• | The engine is cranking at less than 400 RPM for at least 200 ms.

• | This DTC runs once per key cycle within the enabling conditions.

#### P0106 - Engine Running

• | DTCs P0010, P0011, P0013, P0014, P0107, P0108, P0121, P0122, P0123, P0221, P0222, P0223, P0236, P0237, P0238, P0341, P0342, P0343, P0366, P0367, P0368, P2088, P2089, P2090, P2091, P2227, P2228, P2229 are not set.

• | The engine is running and the ECM has counted greater than 200 RPM.

• | The engine speed is greater than 1,500 RPM once during the drive cycle.

• | If start-up ECT is colder than -8°C (+18°F), then the diagnostic is disabled until the ECT reaches 30°C (86°F).

• | The change in the MAP Sensor parameter is greater than 10 kPa once during the drive cycle.

• | The TP Sensor parameter is less than 25 percent once during the drive cycle.

• | This DTC runs continuously within the enabling conditions.

### Conditions for Setting the DTC

#### P0106 - Engine Cranking

The ECM detects when the engine is cranking that the MAP sensor signal plus a calibrated threshold is not within range of a model derived from BARO, and boost pressure for more than 2 seconds.

#### P0106 - Engine Running

• | The ECM detects when the engine is running that the MAP sensor signal is less than or greater than a calibrated minimum/maximum threshold for more than 4 seconds continuously, or 50 seconds cumulative.

• | The ECM detects when the engine is running that the MAP sensor signal plus a calibrated threshold is not within range of a model derived from BARO, boost pressure, throttle opening, and engine speed for more than 4 seconds continuously, or 50 seconds cumulative.

### 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

• | The charge air cooler (CAC) is connected to the turbocharger and to the throttle body by flexible ductwork that requires the use of special high torque fastening clamps. These clamps cannot be substituted. In order to prevent any type of air leak when servicing the ductwork, the tightening specifications and proper positioning of the clamps is critical and must be strictly adhered to.

• | Use a solution of dish soap and water in a spray bottle to pinpoint any suspected air leaks in the induction system and in the CAC assembly.

• | The BARO sensor is integrated within the ECM, and it has a port on the housing that allows it to sense the ambient pressure. A buildup of contamination at this opening may hinder the operation of the BARO sensor.

### Reference Information

#### Schematic Reference

Engine Controls Schematics

#### Connector End View Reference

Component Connector End Views

#### Description and Operation

• | Boost Control System Description

• | Turbocharger System Description

#### 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, P0642, or P0643 are not set.

⇒ | If any of the DTCs are set, refer to DTC P0641-P0643, P0651-P0653, or P0697-P0699.

2. Verify that restrictions do not exist in the exhaust system. Refer to Restricted Exhaust.
3. Verify that the engine is in good mechanical condition. Refer to Symptoms - Engine Mechanical.
4. Ignition OFF for 90 seconds, determine the current vehicle testing altitude.
5. Ignition ON, engine OFF, observe the scan tool BARO parameter, Boost Pressure Sensor parameter, and MAP Sensor parameter. Compare the parameters to the Altitude Versus Barometric Pressure table. The parameters should be within the specified range indicated in the table.
6. Ignition ON, observe the scan tool MAP Sensor parameter. Start the engine. The MAP Sensor parameter should change.
7. Use the scan tool and compare the MAP Sensor parameter to the Boost Pressure Sensor parameter during a WOT acceleration at the time of the 1-2 shift. The readings should be within 20 kPa of each other.
8. 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 air induction system including all turbocharger components by inspecting for the following conditions:

• | Any damaged components

• | Loose or improper installation including the flexible ductwork of the turbocharger and the CAC

• | An air flow restriction

• | Any vacuum leak

• | In cold climates, inspect for any snow or ice buildup at the BARO port on the K20 ECM

• | A restriction in the MAP sensor port or the BARO port

2. Ignition OFF, disconnect the harness connector at the B74 MAP sensor.
3. Ignition OFF for 90 seconds, test for less than 5Ω between the low reference circuit terminal 2 and ground.

⇒ | If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the K20 ECM.

4. Ignition ON, test for 4.8-5.2V between the 5-volt reference circuit terminal 1 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 K20 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 K20 ECM.

5. Verify the scan tool MAP Sensor parameter is less than 1 kPa.

⇒ | If greater than the specified range, test the signal circuit terminal 3 for a short to voltage. If the circuit tests normal, replace the K20 ECM.

6. Install a 3A fused jumper wire between the signal circuit terminal 3 and the 5-volt reference circuit terminal 1. Verify the scan tool MAP Sensor parameter is greater than 254 kPa.

⇒ | If less than the specified range, test the signal circuit terminal 3 for a short to ground or an open/high resistance. If the circuit tests normal, replace the K20 ECM.

7. If the circuits test normal, test or replace the B74 MAP 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. 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.

THEN

4. 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.
5. 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 B74 MAP sensor.
2. Install a 3A fused jumper wire between the 5-volt reference circuit terminal 1 and the corresponding terminal of the MAP sensor.
3. Install a jumper wire between the low reference circuit terminal 2 of the MAP sensor and ground.
4. Install a jumper wire at terminal 3 of the MAP sensor.
5. Connect a DMM between the jumper wire from terminal 3 of the MAP sensor and ground.
6. Ignition ON, with the J 23738-A or the J 35555 , slowly apply vacuum to the sensor while observing the voltage on the DMM. The voltage should vary between 0-5.2V, without any spikes or dropouts.

⇒ | If the voltage reading is erratic, replace the B74 MAP sensor.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Manifold Absolute Pressure Sensor Replacement

• | Control Module References for ECM replacement, setup, and programming