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 Descriptors

DTC P0107 00: Manifold Absolute Pressure Sensor Circuit Low Voltage
DTC P0108 00: Manifold Absolute Pressure Sensor Circuit High Voltage

### Diagnostic Fault Information

Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
5-Volt Reference | P0651 | P0107 | P0651 | --
Signal | P0107 | P0108 | P0108 | --
Low Reference | P0108 | P0108 | -- | --

### Circuit/System Description

The turbocharger pressure sensor measures the pressure inside the intake manifold. Pressure in the intake manifold is affected by turbocharger output, engine speed, accelerator pedal input, air temperature, and barometric pressure (BARO). A diaphragm within the turbocharger pressure sensor is displaced by the pressure changes that occur from the varying load and operating conditions of the engine. The engine control module (ECM) supplies a regulated 5 V to the sensor on the 5-volt reference circuit. The ECM supplies a ground on the low reference circuit. The turbocharger pressure sensor provides a signal voltage to the ECM, relative to the pressure changes, on signal circuit. The ECM converts the signal voltage input to a pressure value. Under normal operation, the lowest pressure that can exist in the intake manifold is equal to the BARO. This occurs when the engine is operating at idle or when the ignition is ON and the engine is OFF. The ECM uses the turbocharger pressure sensor to aid in diagnosis of the turbocharger performance.

### Conditions for Running the DTC

• | DTCs P0069, P0651, P2227 and P2228 are not set.

• | The ignition is ON.

### Conditions for Setting the DTC

The ECM detects the manifold absolute pressure (MAP) sensor signal circuit is open, shorted to ground, or shorted to a voltage for greater than 1 s.

### Action Taken When the DTC Sets

DTCs P0107, and P0108 are Type B DTCs.

### Conditions for Clearing the DTC

DTCs P0107, and P0108 are Type B DTCs.

### Diagnostic Aids

If a shared 5-volt reference circuit is shorted to ground or shorted to a voltage, other 5-volt reference circuits may be affected.

### 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

EN-23738-A Mityvac

For equivalent regional tools, refer to Special Tools.

### Circuit/System Verification

1. Ignition On, observe the DTC information with a scan tool. Verify that DTCs P0651 is not set.

⇒ | If any DTCs are set, refer to Control Module References for further diagnosis.

2. Determine the current vehicle testing altitude. Ignition ON, observe the scan tool BARO Sensor parameter. Compare the parameter to the Altitude Versus Barometric Pressure.
3. Ignition ON, observe the scan tool Boost Pressure Sensor parameter. The Boost Pressure Sensor parameter should match the BARO Sensor parameter.

⇒ | If the BARO Sensor parameter not matches the Boost Pressure Sensor parameter, refer to Circuit/System Testing.

4. 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 by inspecting for the following conditions:

• | Damaged components

• | Loose or improper installation

• | Any vacuum leak

• | Verify there are no restrictions in the turbocharger pressure sensor port or vacuum source.

⇒ | If a condition is found, repair as necessary.

2. Ignition OFF, disconnect the harness connector at the B111 Turbocharger Boost Pressure Sensor.
3. Test for less than 5 Ω between the low reference circuit terminal 1 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 Engine Control Module (ECM).

4. Ignition ON, test for 4.8-5.2 V between the 5-volt reference circuit terminal 3 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 Engine Control Module (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 Engine Control Module (ECM).

5. Verify the scan tool Boost Pressure Sensor parameter is greater than 4.8 V.

⇒ | If less than the specified range, test the signal circuit for a short to ground. If the circuit tests normal, replace the K20 Engine Control Module (ECM).

6. Install a 3 A fused jumper wire between the signal circuit terminal 4 and the 5-volt reference circuit terminal 3. Verify the Boost Pressure Sensor parameter is less than 0.3 V.

⇒ | If greater than the specified range, test the signal circuit for an open circuit or a short to voltage. If the circuit tests normal, replace the K20 Engine Control Module (ECM).

7. If all circuits test normal, test or replace the B111 Turbocharger Boost Pressure Sensor.

### Component Testing

#### Static Test

1. Ignition OFF, remove the turbocharger boost pressure sensor from the intake manifold.
2. Ignition ON, observe and record the scan tool Boost Pressure Sensor parameter. This is the first Boost Pressure Sensor parameter reading.
3. With the EN-23738-A Mityvac apply 50 kPa (7.25 PSI) of pressure to the B111 Turbocharger Boost Pressure Sensor. Observe and record the scan tool Boost Pressure Sensor parameter. This is the second Boost Pressure Sensor parameter reading.
4. Subtract the second Boost Pressure Sensor parameter reading from the first Boost Pressure Sensor parameter reading. Verify that the pressure difference is within 4 kPa (0.58 PSI) of the applied pressure.

⇒ | If not within the specified range, replace the B111 Turbocharger Boost Pressure Sensor.

5. With the EN-23738-A Mityvac apply 100 kPa (14.5 PSI) of pressure to the B111 Turbocharger Boost Pressure Sensor. Observe and record the scan tool Boost Pressure Sensor parameter. This is the third Boost Pressure Sensor parameter reading.
6. Subtract the third Boost Pressure Sensor parameter reading from the first Boost Pressure Sensor parameter reading. Verify that the pressure difference is within 4 kPa (0.58 PSI) of the applied pressure.

⇒ | If not within the specified range, replace the B111 Turbocharger Boost Pressure Sensor.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Link

• | Control Module References for engine control module replacement, setup, and programming