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

### Diagnostic Fault Information

Circuit | Short to Ground | High Resistance | Open | Short to Voltage | Signal Performance
--- | --- | --- | --- | --- | ---
5-Volt Reference | P0107, P0452, P0522, P0532, P0641 | P0106, P0107 | P0107 | P0106, P0108, P0453, P0522, P0533, P0641 | P0106, P0107
MAP Sensor Signal | P0107 | P0106, P0107 | P0107 | P0108 | P0106, P0107, P1101
Low Reference | -- | P0106, P0108 | P0106, P0108 | -- | P0106, P0108

### Typical Scan Tool Data

#### MAP Sensor

Circuit | Normal Range | Short to Ground | Open | Short to Voltage
--- | --- | --- | --- | ---
5-Volt Reference | -- | 10 kPa | 10 kPa | 104 kPa
MAP Sensor Signal | 12-103 kPa | 10 kPa | 10 kPa | 104 kPa
Low Reference | -- | -- | 80-103 kPa | --

### Circuit Description

The manifold absolute pressure (MAP) sensor measures the pressure inside the intake manifold. Pressure in the intake manifold is affected by engine speed, throttle opening, air temperature, and barometric pressure (BARO). A diaphragm within the MAP sensor is displaced by the pressure changes that occur from the varying load and operating conditions of the engine. The sensor translates this action into electrical resistance. The MAP sensor wiring includes 3 circuits. The engine control module (ECM) supplies a regulated 5 volts to the sensor on a 5-volt reference circuit. The ECM supplies a ground on a low reference circuit. The MAP sensor provides a signal voltage to the ECM, relative to the pressure changes, on the MAP sensor signal circuit. The ECM converts the signal voltage input to a pressure value.

Under normal operation the highest pressure that can exist in the intake manifold is equal to BARO. This occurs when the vehicle is operated at wide-open throttle (WOT) or when the ignition is ON while the engine is OFF. Under these conditions, the ECM uses the MAP sensor to determine the current BARO. The lowest manifold pressures occur when the vehicle is idling or decelerating. MAP can range from 10 kPa, when pressures are low, to as much as 104 kPa when pressures are high, depending on the BARO. The ECM monitors the MAP sensor signal for pressure outside of the normal range.

### Conditions for Running the DTC

#### P0107

• | DTCs P0641, P0651, P1516, P2101, P2125, P2135, P2138, P2176 are not set.

• | The engine speed is greater than 400 RPM.

• | The throttle angle is greater than 0 percent when the engine speed is less than 800 RPM.

| OR

• | The throttle angle is greater than 13 percent when the engine speed is greater than 800 RPM.

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

#### P0108

• | DTCs P0101, P0102, P0103, P0120, P0122, P0123, P0220, P0222, P0223, P1516, P2101, P2125, P2135, P2138, P2176 are not set.

• | The engine has been running for a period of time that is determined by the start-up engine coolant temperature (ECT). The time ranges from 8 seconds at less than -30°C (-22°F) to 3 seconds at greater than 30°C (86°F).

• | The throttle angle is less than 1 percent when the engine speed is less than 1,200 RPM.

| OR

• | The throttle angle is less than 20 percent when the engine speed is greater than 1,200 RPM.

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

### Conditions for Setting the DTC

#### P0107

The ECM detects that the MAP sensor voltage is less than 0.2 volt for more than 5 seconds.

#### P0108

The ECM detects that the MAP sensor voltage is more than 4.5 volts for greater than 5 seconds.

### Action Taken When the DTC Sets

DTCs P0107 and P0108 are Type B DTCs.

### Conditions for Clearing the MIL/DTC

DTCs P0107 and P0108 are Type B DTCs.

### Diagnostic Aids

Verify the integrity of the MAP sensor system by inspecting for the following conditions:

• | Intake manifold vacuum leaks

• | Any damage to the MAP sensor housing

• | Any damage to the MAP sensor seal

• | A loose or improperly installed MAP sensor

• | A restriction in the vacuum source of the MAP sensor

### 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

### Circuit/System Verification

• | Use the scan tool and compare the MAP Sensor parameter to a known good vehicle, under various operating conditions.

• | Use the scan tool and compare the MAP Sensor parameter at ignition ON, with the engine OFF, to the Altitude vs Barometric Pressure table. Refer to Altitude Versus Barometric Pressure.

### Circuit/System Testing

Important: All electrical components and accessories must be turned OFF and allowed to power down.

1. Ignition OFF, disconnect the harness connector at the MAP sensor.
2. Ignition OFF, test for less than 5 ohms 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 ECM.

3. Ignition ON, test for 4.8-5.2 volts 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 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.

4. Verify the scan tool MAP Sensor parameter is less than 12 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 ECM.

5. 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 103 kPa.

⇒ | 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.

6. If all circuits test normal, test or replace the MAP sensor.

### Component Testing

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.

1. Turn ON the ignition, with the engine OFF, and remove the 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 the MAP sensor signal circuit terminal 3.
5. Connect a DMM between the jumper wire from the MAP sensor signal circuit and ground.
6. Install the MityVac to the MAP sensor vacuum port. Slowly apply vacuum to the sensor while observing the voltage on the DMM. The voltage should vary between 0-5.2 volts without any spikes or dropouts.

⇒ | If the voltage is not within the specified range or is erratic, 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 ECM replacement, setup, and programming