Manifold Absolute Pressure Sensor, Intake Air Temperature Sensor 1 Checking

Special tools and workshop equipment required 

• Multimeter.
• Wiring diagram.

Test requirements 

• The Engine Control Module (ECM) - J623- fuses OK.
• Battery voltage at least 12.5 volts.
• All electrical consumers such as, lights and rear window defroster, switched off.
• On vehicles with automatic transmission, selector lever in position "P" or "N".
• A/C switched off.
• Ground connections between engine/transmission/chassis OK.
• Ignition switched off.

Test procedure 

-- Perform a preliminary check to verify the customers complaint. Refer to PRELIMINARY CHECK 

Start diagnosis 

-- Remove the engine cover.

Test sequence 

-- Disconnect the Manifold Absolute Pressure Sensor/IAT Sensor 1 -G71/G42- electrical harness connector.

-- Turn the ignition On.

-- Using a multimeter, check the Manifold Absolute Pressure Sensor/IAT Sensor 1 -G71/G42- electrical harness connector terminal 2 to ground for voltage.

Specified value: Near 5.0 V

-- Using a multimeter, check the Manifold Absolute Pressure Sensor/IAT Sensor 1 -G71/G42- electrical harness connector terminal 3 to ground for voltage.

Specified value: Near 5.0 V

-- Using a multimeter, check the Manifold Absolute Pressure Sensor/IAT Sensor 1 -G71/G42- electrical harness connector terminal 4 to ground for voltage.

Specified value: Near 5.6 V

-- Using a multimeter, check the Manifold Absolute Pressure Sensor/IAT Sensor 1 -G71/G42- electrical harness connector terminal 1 to ground for Resistance.

Specified value: 22 Ω or less

-- Switch the ignition OFF.

If all of the specified values were obtained: 

-- Replace the Manifold Absolute Pressure Sensor/IAT Sensor 1 -G71/G42-.

If any of the specified values were Not obtained: 

Checking wiring 

-- Remove the Engine Control Module (ECM) -J623-.

-- Using a multimeter, check the Manifold Absolute Pressure Sensor/IAT Sensor 1 -G71/G42- electrical harness connector terminals to the Engine Control Module (ECM) -J623- electrical harness connector terminals for an open circuit according to wiring diagram.

Manifold Absolute Pressure Sensor/IAT Sensor 1 -G71/G42- electrical harness connector terminals	Engine Control Module (ECM) -J623- electrical connector T60 terminals
1	14
2	13
3	37
4	11

Specified value: 1.5 Ω max.

If the specified value was Not obtained: 

-- Check the wiring for an open, high resistance or short to ground.

-- If necessary, repair the faulty wiring connection.

-- Check the electrical harness connector for damage, corrosion, loose or broken terminals.

If no fault is detected in the wiring and the voltage supply was Not OK: 

-- Replace the Engine Control Module (ECM) -J623-.

-- Install the engine cover.

Final procedures 

After the repair work, the following work steps must be performed in the following sequence:

1. Check the DTC memory. Refer to DIAGNOSTIC MODE 03 - READ DTC MEMORY .
2. If necessary, erase the DTC memory. Refer to DIAGNOSTIC MODE 04 - ERASE DTC MEMORY .
3. If the DTC memory was erased, generate readiness code. Refer to READINESS CODE .