Manifold Absolute Pressure Sensor, Checking

Special tools and workshop equipment required 

• Multimeter.
• Wiring diagram.

Test conditions 

• The Engine Control Module (ECM) -J623- OK.
• The parking brake must be applied, otherwise daytime running lights are switched on.
• On vehicles with automatic transmission, selector lever must be in position "P" or "N".
• The ground connections between engine and body must be OK.

Function test 

-- Connect the scan tool.

-- Start engine and let it run at idle.

-- Using the scan tool, Check the specified value of the Manifold Absolute Pressure (MAP) Sensor -G71- at idle:

Diagnostic text		Specified value
Intake manifold pressure		approx. 100 kPa

If the specified value was obtained:

-- Condition is not present at this time. Check connections for loose or damaged terminals and check harness for an intermittent short.

If the specified value was Not obtained:

Test procedure 

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

-- Disconnect the Manifold Absolute Pressure (MAP) Sensor -G71- electrical harness connector.

-- Start the engine and run at idle speed.

-- Using a multimeter, check the Manifold Absolute Pressure (MAP) Sensor -G71- electrical harness connector terminals 1 to 3 for voltage.

Specification: 4.5 V

-- Switch the ignition OFF.

If the specified value was obtained:

-- Replace Manifold Absolute Pressure (MAP) Sensor -G71-.

If the specified value of 4.5 V was Not obtained:

Checking wiring 

If the manufacturers test box is being used. Perform the following step.

-- Install the test box.

If the manufacturers test box is not being used. Perform the following step.

-- Remove the Engine Control Module (ECM) -J623-. Refer to the Repair information.

-- Using a multimeter, check the Manifold Absolute Pressure (MAP) Sensor -G71- electrical harness connector terminals to the Engine Control Module (ECM) -J623- electrical harness connector T60 terminals for resistance.

Manifold Absolute Pressure (MAP) Sensor -G71- electrical harness connector terminals	Engine Control Module (ECM) -J623- electrical harness connector T60 terminals or test box sockets
1	13
3	29
4	9

Specified value: 1.5 Ω max.

If the specified value was Not obtained:

-- Check the wiring for an open circuit, high resistance, short circuit to each other, Battery (+) or Ground.

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

-- If necessary, repair the faulty wiring connection.

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

-- Replace the Engine Control Module (ECM) -J623-. Refer to the Repair information.

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 .