Hi, there are 3 different engines for the 2005 Cobalt. I have pasted instructions from Autozone.com for all 3 below. I recommend you run the test also pasted below before buying a new sensor. If your sensor passes the test, please get back to me with your symptoms and/or trouble code for alternate repair advice. Please let me know if you have any questions, and thanks for using FixYa.
Removal & Installation
2.0L EngineSupercharger Inlet Pressure (Scip) Sensor
Fig. Manifold Absolute Pressure (MAP) SCIP sensor location-2.0L engine
-
Disconnect the Supercharger Inlet Pressure (SCIP) sensor harness connector.
-
Remove the SCIP sensor (1) from the supercharger.
WARNING: If the SCIP sensor seal is damaged, the SCIP sensor must be replaced.
-
Inspect the seal for damage.
To install:
NOTE
: Use the new SCIP sensor seal provided with the new SCIP sensor.
-
Install the SCIP sensor (1) into the intake manifold. Tighten the bolt to 89 inch lbs. (10 Nm).
-
Connect the SCIP sensor harness connector.
Temperature Manifold Absolute Pressure (Tmap) Sensor
Fig. Manifold Absolute Pressure (MAP) TMAP sensor location-2.0L engine
-
Disconnect the Temperature Manifold Absolute Pressure (TMAP) sensor harness connector.
-
Remove the TMAP sensor from the intake manifold.
WARNING: If the TMAP sensor seal is damaged, the TMAP sensor must be replaced.
-
Inspect the seal for damage.
To install:
NOTE
: Use the new TMAP sensor seal provided with the new TMAP sensor.
-
Install the TMAP sensor into the intake manifold. Tighten the bolt to 89 inch lbs. (10 Nm).
-
Connect the TMAP sensor harness connector.
2.2L & 2.4L Engines
Fig. Manifold Absolute Pressure (MAP) sensor location-2.2L & 2.4L engines
-
Remove the throttle body.
-
Disconnect the engine harness electrical connector from the Manifold Absolute Pressure (MAP) sensor.
-
Remove the MAP sensor and seal.
To install:
-
Lubricate the NEW MAP sensor seal with clean engine oil.
-
Install the MAP sensor into the intake manifold.
-
Connect the engine harness electrical connector to the MAP sensor.
-
Install the throttle body.
Testing
-
Verify the integrity of the entire air induction system by inspecting for the following conditions:
Any damage to, or hairline fractures of, the MAP sensor housing,
Loose or improper installation,
Any vacuum leak
-
Verify that restrictions do not exist in the MAP sensor port or vacuum source.
-
Determine the current vehicle testing altitude. Ignition ON, observe the scan tool BARO Sensor parameter.
-
Use the scan tool and compare the MAP Sensor parameter to a known good vehicle, under various operating conditions.
Circuit Testing
Fig. Manifold Absolute Pressure (MAP) connector end view-2.0L & 2.2L engines
Fig. Manifold Absolute Pressure (MAP) connector end view-2.4L engine
NOTE
All electrical components and accessories must be turned OFF, and allowed to power down.
-
With the ignition OFF, disconnect the MAP harness connector at the MAP sensor.
-
Test for less than 5 ohms of resistance between the low reference
circuit terminal 2 and ground-2.0L & 2.2L (A and ground-2.4L).
-
If greater than the specified range, test the low reference circuit for an open/high resistance.
-
If the circuit tests normal, replace the ECM.
-
With the ignition ON, test for 4.8-5.2 volts between the 5 volt
reference circuit terminal 1 and ground-2.0L & 2.2L (C and
ground-2.4L).
-
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.
-
Verify the scan tool MAP sensor parameter is less than 1 kPa.
-
If greater than the specified range, test the signal circuit terminal 3-2.0L & 2.2L for a short to voltage.
-
If the circuit tests normal, replace the ECM.
-
Install a 3A fused jumper wire between the signal circuit terminal
3-2.0L & 2.2L and the 5 volt reference circuit terminal 1-2.0L
& 2.2L. Verify the scan tool MAP sensor parameter is greater than
126 kPa.
-
If less than the specified range, test the signal circuit terminal
3-2.0L & 2.2L for a short to ground or an open/high resistance.
-
If the circuit tests normal, replace the ECM.
-
If all circuits test normal, test or replace the MAP sensor.
Component Testing
NOTE
You must perform the circuit/system testing, in order to verify
the integrity of the MAP sensor circuits, before proceeding with the
component testing.
-
Turn ON the ignition, with the engine OFF, and remove the MAP sensor.
-
Install a 3A fused jumper wire between the 5 volt reference
circuit terminal 1-2.0L & 2.2L and the corresponding terminal of the
MAP sensor.
-
Install a jumper wire between the low reference circuit terminal 2-2.0L & 2.2L of the MAP sensor and ground.
-
Install a jumper wire at terminal 3-2.0L & 2.2L of the MAP sensor.
-
Connect a DMM between the jumper wire from terminal 3 of the MAP sensor and ground.
-
Install the J 35555 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.