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 P0069 5A: Manifold Absolute Pressure (MAP) - Barometric Pressure (BARO) Not Plausible

### Circuit/System Description

The turbocharger pressure sensor responds to pressure changes in the intake manifold. The pressure changes occur based on the engine load, and turbocharger boost. The engine control module (ECM) supplies 5 volts to the turbocharger pressure sensor on the 5-volt reference circuit. The ECM provides a ground on the low reference circuit. The turbocharger pressure sensor provides a signal to the ECM on the sensor signal circuit which is relative to the pressure changes in the manifold. The ECM detects a low signal voltage at a low MAP, such as during deceleration. The ECM detects a high signal voltage at a high MAP, such as the ignition is ON, with the engine OFF, or at idle. The barometric pressure (BARO) sensor is internal to the ECM. This location allows for constant monitoring of the barometric pressure. The ECM compares the turbocharger pressure sensor signal to the internal BARO sensor signal when the ignition switch is turned ON, with the engine OFF.

### Condition for Running the DTC

• | DTCs P0105, P0107, or P0108 are not set.

• | The ignition is ON.

• | The DTC runs continuously when the above conditions are met.

### Conditions for Setting the DTC

The ECM detects that the difference between the MAP signal and the BARO signal is greater than 20 kPa for 1 second.

### Action Taken When the DTC Sets

DTC P0069 is a Type B DTC.

### Conditions for Clearing the DTC

DTC P0069 is a Type B DTC.

### 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.

• | The scan tool 5-volt reference parameters should display OK.

### 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 Mity Vac

### Circuit/System Verification

1. Ignition ON, observe the DTC information with a scan tool. DTC P0069 5A should not set.

Note: The vehicle used for the comparison is not limited to the same type of vehicle being serviced. A vehicle known to provide an accurate reading is acceptable.

2. Compare the scan tool MAP sensor pressure parameter, and the scan tool BARO sensor pressure parameter, to the pressure parameter of a known good vehicle. Both readings should be within 3 kPa of the known good vehicle.

Note: The Altitude vs Barometric Pressure table indicates a pressure range for a given altitude under normal weather conditions. Weather conditions consisting of very low or very high pressure and/or very low or very high temperature may cause a reading to be slightly out of range.

3. Compare the scan tool MAP sensor pressure parameter, and the scan tool BARO sensor pressure parameter, to the reading in the Altitude Versus Barometric Pressure table. Both parameters should be within the specified range indicated on the table.
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. Ignition ON, compare the scan tool BARO pressure sensor parameter to the reading in the Altitude Versus Barometric Pressure table.

⇒ | If not within the specified range, refer to DTC P0105 for further diagnosis.

2. Ignition OFF, and the MAIN fuse removed, disconnect the harness connector at the turbocharger boost pressure sensor.
3. Test for less than 5 Ω between the low reference circuit terminal 4 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. Install the MAIN fuse. Ignition ON, test for 4.8-5.2 A between the 5-volt reference circuit terminal 2 and ground.

⇒ | If less than the specified range, test the 5-volt reference circuit for a short to ground or 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 pressure parameter is less than 24 kPa.

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

6. Install a 3 A fused jumper wire between the signal circuit terminal 1 and the 5-volt reference circuit terminal 2. Verify the MAP sensor parameter is between 40-45 kPa.

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

⇒ | If greater than the specified range, test the signal circuit for a high resistance. If the circuit tests normal, replace the K20 ECM.

7. If all circuits test normal, test or replace the turbocharger boost pressure sensor.

### Component Testing

1. Ignition OFF, perform one of the following applicable procedures.

• | Disconnect the vacuum supply hose from the turbocharger boost pressure sensor

• | Remove the turbocharger boost pressure sensor from the intake manifold

2. Ignition ON, observe and record the scan tool MAP sensor pressure sensor data parameter. This is the first MAP sensor reading.
3. Engine running, with the J 23738-A Mity Vac apply 5 in Hg (17 kPa) of vacuum to the turbocharger boost pressure sensor. Observe and record the scan tool MAP sensor pressure sensor data parameter. This is the second MAP sensor reading.
4. Subtract the second MAP sensor reading from the first MAP sensor reading. Verify that the vacuum decrease is within 1 in Hg (4 kPa) of the applied vacuum.

⇒ | If not within the specified range, replace the MAP sensor.

5. With the J 23738-A Mity Vac apply 10 in Hg (34 kPa) of vacuum to the turbocharger boost pressure sensor. Observe and record the scan tool MAP sensor pressure data parameter. This is the third MAP sensor reading.
6. Subtract the third MAP sensor reading from the first MAP sensor reading. Verify that the vacuum decrease is within 1 in Hg (4 kPa) of the applied vacuum.

⇒ | If not with in the specified range, replace the turbocharger boost pressure sensor.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Intake Air Pressure and Temperature Sensor Replacement

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