Intake Flap Motor, Checking

Special tools and workshop equipment required 

• Multimeter.
• Wiring diagram.

Test requirements 

• The Intake Flap Motor -V157- fuse OK.
• The Engine Component Power Supply Relay -J757- OK.
• The parking brake engaged.
• The battery voltage at least 12.5 V.
• The selector lever of automatic transmission in position "P" or "N".
• All electrical consumers switched off (radiator fan must NOT run during test).
• A/C switched off.
• The fuel tank at least ¹ /₄ filled.
• The ignition switched off.

Test procedure 

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

Start diagnosis 

Procedure 

-- Remove the rear engine cover -arrows-.

-- Disconnect the Intake Flap Motor -V157- electrical harness connector -5-.

Checking internal resistance 

-- Using a Multimeter --, check the Intake Flap Motor -V157- terminals 1 to 2 for resistance

Intake Flap Motor -V157- terminals
1 to 2

Specified value: 450 to 1000 Ω.

If the specified value was not obtained:

-- Replace the Intake Flap Motor -V157-.

If the specified value was obtained:

Checking voltage 

Switch the ignition on.

-- Using a Multimeter --, check the Intake Flap Motor -V157- electrical harness connector terminal 1 to ground (GND) for voltage.

Specified value: battery voltage.

-- Switch the ignition off.

If the specified value was not obtained:

-- Check the wiring from the Intake Flap Motor -V157- electrical harness connector terminal 1 to the Engine Component Power Supply Relay -J757- terminal 2/87 for a short circuit to Ground (GND), or an open circuit.

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

-- If necessary, repair the wiring connection.

If no malfunctions are found in the wiring:

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 Motronic Engine Control Module (ECM) -J623-. Refer to ENGINE CONTROL MODULE, REPLACING .

-- Using a multimeter --, check the Intake Flap Motor -V157- electrical harness connector terminal 2 to the Engine Control Module (ECM) -J623- electrical harness connector T60 terminal 6 for an open circuit.

Intake Flap Motor -V157- electrical harness connector	Engine Control Module (ECM) -J623- electrical harness connector T60 terminals or test box socket
1	63
2	6
3	40

Specified value: 1.5 Ω Max.

If the specification was not obtained:

-- Check the wiring for a short circuit to each other, Battery (+), and Ground (GND).

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

-- If necessary, repair the faulty wiring connection.

-- Erase the DTC memory. Refer to DIAGNOSTIC MODE 04 - ERASE DTC MEMORY .

-- Perform a road test to verify repair.

If the DTC does not return:

Repair complete, Generate readiness code. Refer to READINESS CODE .

-- End diagnosis.

If the DTC does return and no malfunction is detected in the wiring and the voltage supply was OK:

-- Replace the Motronic Engine Control Module (ECM) -J623-. Refer to ENGINE CONTROL MODULE, REPLACING .

-- Assembly is performed in the reverse of the removal.

Final procedures 

After repair work, the following work steps must be performed in the mentioned 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 .