Leak Detection Pump, Checking

Special tools and workshop equipment required 

• Multimeter.
• Wiring diagram.

Test requirements 

• The Fuse -S282- fuse OK.
• The ignition switched off.

Procedure 

-- Remove left rear wheel housing liner Removal and Installation .

-- Remove theLeak Detection Pump (LDP) --V144-- nuts -arrows-.

-- Remove theLeak Detection Pump (LDP) --V144-- with bracket attached.

-- Disconnect the Leak Detection Pump (LDP) -V144- electrical harness connector -3-.

Checking internal resistance

-- Using a Multimeter --, check the Leak Detection Pump (LDP) -V144- for resistance as follows:

Leak Detection Pump (LDP) -V144- electrical harness connector terminals	Specified value
-1- + -3-	640 to 720 Ω
-2- + -3-	15 to 17 Ω

If any of the specifications were not obtained:

-- Replace the Leak Detection Pump (LDP) --V144--. Fuel Supply System .

If the specified values were obtained:

Checking voltage supply

-- Using a Multimeter --, check the Leak Detection Pump (LDP) --V144-- electrical harness connector terminal 3 to Ground (GND) for voltage.

Leak Detection Pump (LDP) --V144-- electrical harness connector terminal	Measure to
-3-	Engine Ground (GND)

-- Operate the starter briefly.

Specified value: battery voltage.

-- Switch the ignition off.

If the specified value was not obtained:

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

-- Check the wiring for a short circuit to Ground (GND) or an open circuit.

-- If necessary, repair the faulty wiring connection.

It the specification was 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 Motronic Engine Control Module (ECM) -J623-. Refer to ENGINE CONTROL MODULE, REMOVING AND INSTALLING .

-- Using a Multimeter --, check the Leak Detection Pump (LDP) --V144-- electrical harness connector terminals to theMotronic Engine Control Module (ECM) -J623- electrical harness connectors T94a and T60a terminals for an open circuit.

Leak Detection Pump (LDP) --V144-- electrical connector terminals	Motronic Engine Control Module (ECM) -J623- electrical connector T94a terminal or test box socket
-1-	40

Leak Detection Pump (LDP) --V144-- electrical connector terminals	Motronic Engine Control Module (ECM) -J623- electrical connector T60a terminal or test box socket
-2-	55

Specified value: 1.5 Ω.

If the specification is not obtained:

-- Check the wiring for a short circuit to Battery positive (+) or an open circuit.

-- If necessary, repair the wiring connection.

If no malfunction is found in wiring:

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

Assembly is performed in the reverse order of removal.

-- Install the left rear wheel housing liner Removal and Installation .

Final procedures 

After 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 .

-- End of diagnosis.