Diagnostic Instructions

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	Open/High Resistance	Short to Voltage	Signal Performance
5-Volt Reference	P0107, P0404	P0107	P0108	--
MAP Sensor Signal	P0107	P0107	P0108	--
Low Reference	--	P0108	--	--

Typical Scan Tool Data

MAP Sensor

Circuit	Short to Ground	Open	Short to Voltage
Operating Conditions: Engine operating in Closed Loop. Parameter Normal Range: 45-55 kPa
5-Volt Reference	50 kPa,	50 kPa,	121 kPa,
MAP Sensor Signal	50 kPa,	50 kPa,	121 kPa,
Low Reference	--	113 kPa,	121 kPa*,
* 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 engine is operated at or near WOT.

Conditions for Running the DTC

P0107 Conditions 1

P0107 Conditions 2

P0107 Conditions 3

P0108

Conditions for Setting the DTC

P0107

The ECM detects that the MAP sensor is less than 15 kPa.

P0108

The ECM detects that the MAP sensor is more than 95 kPa.

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

Electrical Information Reference

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Special Tools Required

J 23738-A Mityvac

Circuit/System Verification

1. Engine running, increase the engine speed to 2,000 RPM. Verify the scan tool MAP Sensor pressure parameter is between 30-40 kPa.
2. Cycle the throttle from idle to 2,000 RPM while observing the scan tool MAP sensor pressure parameter. The MAP sensor pressure parameter should change. Repeat the procedure as necessary.
3. 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 OFF, disconnect the harness connector at the MAP sensor.
2. Ignition OFF, test for less than 5 ohms of resistance between the low reference circuit terminal A 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.

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.

3. Ignition On, test for 4.8-5.2 volts between the 5-volt reference circuit terminal C 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 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 pressure parameter is at 50 kPa.

⇒	If greater than the specified range, test the signal circuit 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 B and the 5-volt reference circuit terminal C. Verify the scan tool MAP sensor pressure parameter is greater than 50 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

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 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 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 the vacuum decrease is within 1 in Hg (4 kPa) of the applied vacuum.

⇒	If not with in the specified range, replace the MAP sensor.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.