General information
The intake manifold absolute pressure sensor is a variable resistance that is sensitive to changes in pressure. It detects the change in intake manifold pressure, which depends on the engine load and engine speed, and converts this value into a signal voltage (when the pressure decreases, the voltage drop of the sensor signal increases). The MAP signal is used by the ECM to measure barometric pressure at engine start and under certain other conditions, allowing the system to automatically adjust system performance at various altitudes.
The intake air temperature sensor, integrated in the intake manifold absolute pressure sensor, is a resistive type sensor that is sensitive to changes in air temperature.
Based on the sensor signals, the electronic engine control unit determines the required fuel supply (basic fuel injector open time) and ignition timing.
- Rated supply voltage of the sensor: 4.8-5.2 V
Troubleshooting Guide
Under the following conditions, the engine malfunction indicator lights up "CHECK ENGINE" and the corresponding fault code is displayed:
- 1. If the intake manifold pressure is 11.8 kPa or lower within 0.1 second after the ignition is turned on.
- 2. If the intake manifold pressure is 11.8 kPa or lower when the engine is running at 1980 rpm or less.
- 3. If the intake manifold pressure is 98.6 kPa or higher and the engine is running at 2400 rpm or higher with the accelerator pedal released (e.g. when the vehicle is moving downhill).
Checking the absolute pressure sensor in the intake manifold
1. Measure the voltage between the terminals "1" (signal) And "4" ("weight") connector on the sensor side under the specified conditions when the connector is connected.
- A) Check the voltage when the ignition key is set to "ON" (ON) and the engine is not running.
- Rated value: 4-5V
- b) Check the voltage when the ignition key is set to "ON" (ON) and the engine is idling.
- Rated value: 0.8-2.4V
- V) With the engine idling, depress the accelerator pedal sharply and check that the voltage rises from the nominal value.
- Rated value: 0.8-2.4V
2. If the measured voltage differs from the nominal value, then replace the absolute pressure sensor in the intake manifold.
Checking the intake air temperature sensor
1. Using a multimeter, measure the resistance between the terminals "2" And "3" intake manifold absolute pressure sensor connector.
Table. Rated values
Air temperature | Rated value |
At 0°C | 3.3-3.7 ohm |
At 20°C | 2.4-2.8 ohm |
At 40°C | 1.6-2.0 ohm |
At 80°C | 0.5-0.9 ohm |
2. If the measured resistance differs from the nominal value, then replace the absolute pressure sensor in the intake manifold.
Checking the intake air temperature sensor with a tester
1. Conditions for the audit.
Ignition key: in position "ON" (ON) or the engine is running.
2. Performing a check:
Read tester readings (Air temperature in the intake manifold).
Table. Rated values.
Engine condition | Rated value |
At -20°С | -20°С |
At 0°C | 0°C |
At 20°C | 20°C |
At 40°C | 40°C |
At 80°C | 80°С |
2. If the tester readings differ from the nominal value, then replace the absolute pressure sensor in the intake manifold.