Component Location
P0108 Manifold Absolute Pressure Circuit High Input
General Description
Manifold absolute pressure sensor is located on the intake manifold and is together with intake air temperature sensor. Manifold absolute pressure sensor senses air pressure entering cylinder as an absolute pressure and relays signals to ETCM. ETCM uses these signals for injection quantity correction, injection time correction.
DTC Description
If the output voltage of the manifold absolute pressure sensor is below 0.2V for more than 1.0 second at idle, at starting or at driving, ETCM judges this as a fault and DTC is set. The possible causes may be open in harness, short to ground, poor connection of connector. In case of fail safe, ETCM sets fuel pressure to 150Kpa at starting, at idle and at driving. Therefore, vehicle can be driven but lack of engine power, black smoke can occur.
DTC Detecting Condition
| Item | Detecting Condition | Possible Cause | ||
| DTC Strategy | • Voltage monitoring | • Poor connection of connector
• Short to ground |
||
| Enable Conditions |
• At starting/ At idle/ At driving | |||
| Threshold Value |
• Above 4.9V | |||
| Diagnosis Time |
• Above 1.0 second | |||
| Fail Safe | Fuel Cut | No | • Lack of power, black smoke
• Manifold absolute pressure : 150Kpa |
|
| Fuel Limit | Yes | |||
| MIL | On | |||
Specification
1. Manifold absolute pressure sensor resistance
| Temp.(℃) | Resistance between terminal ① and ④ (Ω) | ||
| Min | Type | Max | |
| 20±1 | 2,311 | 2,438 | 2,565 |
Diagnostic Circut Diagram
Monitor Scantool Data
1. Connect scantool to Data Link Connector(DLC).
2. Warm up the engine to normal operating temperature.
3. Turn the electrical equipment and air conditioner OFF.
4. Monitor “Intake Air Pressure Sensor” parameter on the scantool.
Intake air pressure sensor data is displayed on the scantool depending on DTC detecting condition. (Refer to voltage variation according to temperature.)
System Inspection
1. Intake Air Leaks Inspection
(1) Check the intake air for shortage.
(2) Check the air cleaner element.
(3) Check that air inputted from intake system includes dust or foreign material.
(4) Check the turbo charger and intake muffler for damage.
2. Is the intake system normal?
| Yes | ▶ Go to next procedure. |
| No | ▶ Repair as necessary and then go to “Verification of Vehicle Repair” procedure. |
Terminal & Connector Inspection
1. Many malfunctions in the electrical system are caused by poor harness and terminals. Faults can also be caused by interference from other electrical systems, and mechanical or chemical damage.
2. Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage.
3. Has a problem been found?
| Yes | ▶ Repair as necessary and then go to “Verification of Vehicle Repair” procedure |
| No | ▶ Go to “Inspection and Repair” procedure. |
Signal Circuit Inspection
1. Signal Voltage Inspection
(1) Leave the manifold absolute pressure sensor connector connected.
(2) IG “ON”, and set the start safety switch ON. Leave the engine “OFF”.
(3) Measure voltage between terminal 1 of the manifold absolute pressure sensor harness connector and chassis ground.
- Specification : Approx. 1.0V
Signal voltage is varied according to manifold absolute pressure
(4) Is the voltage measured within specification?
| Yes | ▶ Go to “Power Circuit Inspection” procedure |
| No | ▶ Go to “Signal short to Power Inspection” procedure. |
2. Signal Short to Power Inspection
(1) Disconnect the manifold absolute pressure sensor connector and the ETCM connector.
(2) IG “ON”, and set the start safety switch ON. Leave the engine “OFF”.
(3) Measure voltage between terminal 1 of the manifold absolute pressure sensor harness connector and chassis ground.
- Specification: Below 0~0.1V
(4) Is the voltage measured within specification?
| Yes | ▶ Go to “Power Circuit Inspection” procedure. |
| No | ▶ Repair short to power and then go to “Verification of Vehicle Repair” procedure. |
Power Circuit Inspection
1. Power Voltage Inspection
(1) Disconnect the manifold absolute pressure sensor connector.
(2) IG “ON”, and set the start safety switch ON. Leave the engine “OFF”.
(3) Measure voltage between terminal 2 of the manifold absolute pressure sensor harness connector and chassis ground.
- Specification : Approx. 5.0V
(4) Is the voltage measured within specification?
| Yes | ▶ Go to “Ground Circuit Inspection” procedure. |
| No | ▶ Go to “Short to Power Inspection” procedure. |
2. Short to Power Inspection
(1) Disconnect the manifold absolute pressure sensor connector and the ETCM connector.
(2) IG “ON”, and set the start safety switch ON. Leave the engine “OFF”.
(3) Measure voltage between terminal 2 of the manifold absolute pressure sensor harness connector and chassis ground.
- Specification: Below 0 ~ 0.1V
(4) Is the voltage measured within specification?
| Yes | ▶ Go to “Ground Circuit Inspection” procedure |
| No | ▶ Repair short to power and then go to “Verification of Vehicle Repair” procedure. |
Ground Circuit Inspection
1. Voltage Drop Inspection
(1) Disconnect the manifold absolute pressure sensor connector.
(2) IG “ON”, and set the start safety switch ON. Leave the engine “OFF”.
(3) Measure voltage drop between terminal 4 of the manifold absolute pressure sensor harness connector and chassis ground.
- Specification: Below 200mV
(4) Is the voltage drop measured within specification?
| Yes | ▶ Go to “Ground Open Inspection” procedure. |
| No | ▶ Repair poor connection in ground circuit and then go to “Verification of Vehicle Repair” procedure. |
2. Ground Open Inspection
(1) IG “OFF”, and set the start safety switch ON.
(2) Disconnect the manifold absolute pressure sensor connector and ETCM connector.
(3) Measure resistance between terminal 4 of the manifold absolute pressure sensor harness connector and terminal 27 of ETCM connector
- Specification: Continuity(Below 1.0 Ω)
(4) Is the resistance measured within specification?
| Yes | ▶ Go to “Component Inspection” procedure. |
| No | ▶ Repair open in circuit and then go to “Verification of Vehicle Repair” procedure. |
Component Inspection
1. Manifold Absolute Pressure Sensor Resistance Inspection
(1) IG “OFF”, and set the start safety switch ON.
(2) Disconnect the Manifold Absolute pressure sensor connector.
(3) Measure resistance between terminals 1 and 4 of Manifold Absolute pressure sensor.
- Specification:
| Temp.(℃) | Resistance between terminal ① and ④ (Ω) | ||
| Min | Type | Max | |
| 20±1 | 2,311 | 2,438 | 2,565 |
(4) Is the resistance measured within the specification?
| Yes | ▶ Go to “Verification of Vehicle Repair” procedure. |
| No | ▶ Replace the manifold absolute pressure sensor and then go to “Verification of Vehicle Repair” procedure. |
Verification of Vehicle Repair
After a repair, it is essential to verify that the fault has been corrected.
1. Connect scantool and select “Diagnostic Trouble Codes(DTCs)” mode.
2. Using a scantool, clear the DTC.
3. Operate the vehicle within DTC enable conditions in General Information.
4. Are any DTCs present?
| Yes | ▶ Go to the applicable DTC procedure. |
| No | ▶ System is performing to specification at this time |
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