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 provide an overview of each diagnostic category.

### DTC Descriptors

DTC P0107: Manifold Absolute Pressure (MAP) Sensor Circuit High Voltage
DTC P0108: Manifold Absolute Pressure (MAP) Sensor Circuit Low Voltage

### Diagnostic Fault Information

Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
5-volt Reference Voltage | P0107 | P0107 | P0108 | --
MAP Sensor Signal | P0107 | P0107 | P0108 | --
Low Reference | -- | P0107 | -- | --

### Typical Scan Tool Data

#### MAP Sensor

Circuit | Short to Ground | Open | Short to Voltage
--- | --- | --- | ---
Operating Conditions: Engine operating in Closed Loop. Parameter Normal Range: 32-42 kPa
5-volt Reference Voltage | 10 kPa | 10 kPa | 104 kPa
MAP Sensor Signal | 10 kPa | 10 kPa | 104 kPa
Low Reference | -- | 10 kPa | --
¹ Internal ECM damage may occur if the circuit is shorted to B+

### Circuit/System Description

The manifold absolute pressure (MAP) sensor responds to pressure changes in the intake manifold. The pressure changes occur based on the engine load. The engine control module (ECM) supplies 5 volts to the MAP sensor on the 5-volt reference circuit. The ECM provides a ground on the low reference circuit. The MAP sensor provides a signal to the ECM on the MAP 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 an idle or a deceleration. The ECM detects a high signal voltage at a high MAP, such as the ignition is ON, with the engine OFF, or at a wide open throttle (WOT). The MAP sensor is also used to determine the barometric pressure (BARO). This occurs when the ignition switch is turned ON, with the engine OFF. The BARO reading may also be updated whenever the TP sensor is greater than 28 percent.

### Conditions for Running the DTC

#### P0107

• | DTCs P0122, P0123, P1121, P1122 are not set.

• | The TP sensor is greater than or equal to 0 percent while the engine speed is less than 1,500 RPM or the TP sensor is greater than 10 percent while the engine speed is greater than 1,500 RPM.

• | The ignition 1 voltage is greater than 11.5 volts.

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

#### P0108

• | DTCs P0122, P0123, P1121, and P1122 are not set.

• | The engine has been running for more than 10 seconds.

• | The TP sensor is less than 20 percent while the engine speed is less than 3,000 RPM or the TP sensor is less than 30 percent while the engine speed is greater than 3,000 RPM.

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

### Conditions for Setting the DTC

#### P0107

The ECM detects that the MAP is less than 12 kPa for more than 5 seconds.

#### P0108

The ECM detects that the MAP is more than 103 kPa for more than 5 seconds.

### Action Taken When the DTC Sets

DTC P0107 and P0108 are Type A DTCs.

### Conditions for Clearing the MIL/DTC

DTC P0107 and P0108 are Type A 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

• | Engine Control Module Connector End Views

• | Engine Controls 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

• | Scan Tool Data List

• | Scan Tool Data Definitions

• | Scan Tool Output Controls

#### Special Tools Required

J 23738-A Vacuum Pump

### Circuit/System Verification

1. Start the engine, observe the MAP Sensor parameter. The reading should be between 32-42 kPa.
2. If the vehicle passes the Circuit/System Verification Test, then operate the vehicle within the conditions for running the DTC. You may also operate the vehicle within the conditions that are captured in the Freeze Frame/Failure Records Data List.

### Circuit/System Testing

1. Ignition OFF, disconnect the harness connector of the MAP sensor.
2. Ignition ON, test for less than 0.2 volt between the low reference circuit and ground.

⇒ | If greater than the specified value, test the low reference circuit for a short to voltage. If the circuit/connections test normal, replace the ECM.

3. Ignition OFF, test for less than 5 ohms of resistance between the low reference circuit and ground.

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

Important: The 5-volt reference circuits are internally and externally connected at the ECM. Other component DTCs may be set. If other DTCs are set, review the electrical schematic and diagnose the applicable circuits and components.

4. Ignition ON, load test for 4.8-5.2 volts between the 5-volt reference circuit 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/connections test normal, replace the ECM.

⇒ | If greater than the specified range, test the 5-volt reference circuit for a short to voltage. If the circuit/connections test normal, replace the ECM.

5. Observe the scan tool MAP sensor pressure parameter. Verify that the MAP sensor parameter is less than 12 kPa.

⇒ | If greater than the specified value, test the signal circuit for a short to voltage. If the circuit/connections test normal, replace the ECM.

6. Install a 3-amp fused jumper wire between the signal circuit and the 5-volt reference circuit. Verify that the scan tool MAP sensor pressure parameter is greater than 102 kPa.

⇒ | If less than the specified value, test the signal circuit for a short to ground or an open/high resistance. If the circuit/connections test normal, replace the ECM.

7. If all circuits/connections test normal, test or replace the MAP sensor.

### Component Testing

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

• | Disconnect the vacuum supply hose from the MAP sensor

• | Remove the MAP sensor from the intake manifold

2. Ignition ON, observe and record the scan tool MAP sensor pressure data parameter. This is the first MAP sensor reading.
3. With the J 23738-A apply 5 in Hg (17 kPa) of vacuum to the MAP sensor. Observe and record the scan tool MAP sensor pressure 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 the vacuum decrease is not within the specified range, replace the MAP sensor.

5. With the J 23738-A apply 10 in Hg (34 kPa) of vacuum to the MAP 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 the vacuum is not with in the specified range, replace the MAP sensor.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Manifold Absolute Pressure Sensor Replacement

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