Fuel Injectors, Checking

Fuel Injectors

The following test procedure is used to diagnose the five fuel injectors controlled by the Engine Control Module (ECM) -J623-.

Special tools and workshop equipment required 

• Multimeter.
• Diode test lamp (12V).
• Wiring diagram.

Test requirements 

• The Engine Control Module (ECM) -J623- fuses OK.
• The Engine Speed (RPM) Sensor -G28- OK.
• Battery voltage at least 12.5 volts.
• All electrical consumers such as, lights and rear window defroster, switched off.
• Vehicles with automatic transmission, shift selector lever into position "P" or "N".
• A/C switched off.
• Ground (GND) connections between engine/transmission/chassis OK.
• Ignition switched off.

-- Observe safety precautions.

-- Observe rules for cleanliness.

Procedure 

-- Remove the intake manifold. Refer to Intake Manifold .

-- Disconnect the Fuel Injector -- electrical harness connector -arrow- from the Fuel Injector -- to be tested.

Checking internal resistance

-- Using a multimeter, check terminals 1 to 2 of the Fuel Injector -- to be tested for resistance.

Specified value: 12.0 to 20.0 Ω (at approx. 20° C)

If the specified value was not obtained:

-- Replace the faulty Fuel Injector --. Refer to Fuel Injectors .

If the specified value was obtained:

Checking activation

-- Connect a diode test lamp (12V) to the Fuel Injector -- electrical harness connector terminals 1 and 2 of the Fuel Injector -- to be tested.

-- Operate the starter and test the activation of the Fuel Injector --.

LED should flicker.

-- Switch the ignition off.

If LED flickers:

-- Replace the faulty Fuel Injector -- Refer to Fuel Injectors . .

If LED does not flicker:

Checking activation and wiring

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

-- Install the test box. Refer to Wiring and Components, Checking with Test Box VAG 1598/42 .

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 electrical harness connector terminals of the Fuel Injector -- to be tested to the Motronic Engine Control Module (ECM) -J623- electrical harness connector T60a terminals for an open circuit.

Component	Fuel Injector -- electrical harness connector terminals	Motronic Engine Control Module (ECM) -J623- electrical connector T60a terminals or test box sockets
Cylinder 1 Fuel Injector -N30-	1	33
	2	2
Cylinder 2 Fuel Injector -N31-	1	31
	2	18
Cylinder 3 Fuel Injector -N32-	1	48
	2	16
Cylinder 4 Fuel Injector -N33-	1	32
	2	1
Cylinder 5 Fuel Injector -N83-	1	32
	2	17

Specified value: 1.5 Ω Max.

If the specification is not obtained:

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

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

-- If necessary, repair the faulty wiring connection.

If no malfunction is detected in the 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 intake manifold. Refer to Intake Manifold .

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.

Fuel Injectors

The following test procedure is used to diagnose all fuel injectors controlled by the Engine Control Module (ECM) 2 -J624-.

Special tools and workshop equipment required 

• Multimeter.
• Diode test lamp (12V).
• Wiring diagram.

Test requirements 

• The Engine Control Module (ECM) 2 -J624- fuses OK.
• The Engine Speed (RPM) Sensor -G28- OK.
• Battery voltage at least 12.5 volts.
• All electrical consumers such as, lights and rear window defroster, switched off.
• Vehicles with automatic transmission, shift selector lever into position "P" or "N".
• A/C switched off.
• Ground (GND) connections between engine/transmission/chassis OK.
• Ignition switched off.

-- Observe safety precautions.

-- Observe rules for cleanliness.

Procedure 

-- Remove the intake manifold. Refer to Intake Manifold .

-- Disconnect the Fuel Injector -- electrical harness connector -arrow- from the Fuel Injector -- to be tested.

Checking internal resistance

-- Using a multimeter, check terminals 1 to 2 of the Fuel Injector -- to be tested for resistance.

Specified value: 12.0 to 20.0 Ω (at approx. 20° C)

If the specified value was not obtained:

-- Replace the faulty Fuel Injector --. Refer to Fuel Injectors . .

If the specified value was obtained:

Checking activation

-- Connect a diode test lamp (12V) to the Fuel Injector -- electrical harness connector terminals 1 and 2 of the Fuel Injector -- to be tested.

-- Operate the starter and test the activation of the Fuel Injector --.

LED should flicker.

-- Switch the ignition off.

If LED flickers:

-- Replace the faulty Fuel Injector --. Refer to Fuel Injectors . .

If LED does not flicker:

Checking activation and wiring

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

-- Install the test box. Refer to Wiring and Components, Checking with Test Box VAG 1598/42 .

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

-- Remove the Engine Control Module (ECM) 2 -J624-. Refer to ENGINE CONTROL MODULE, REMOVING AND INSTALLING .

-- Using a Multimeter --, check the electrical harness connector terminals of the Fuel Injector -- to be tested to the Engine Control Module (ECM) 2 -J624- electrical harness connector T60b terminals for an open circuit.

Component	Fuel Injector -- electrical harness connector terminals	Engine Control Module (ECM) 2 -J624- electrical connector T60b terminals or test box sockets
Cylinder 6 Fuel Injector -N84-	1	33
	2	2
Cylinder 7 Fuel Injector -N85-	1	31
	2	18
Cylinder 8 Fuel Injector -N86-	1	48
	2	16
Cylinder 9 Fuel Injector -N299-	1	32
	2	1
Cylinder 10 Fuel Injector -N300-	1	32
	2	17

Specified value: 1.5 Ω Max.

If the specification is not obtained:

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

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

-- If necessary, repair the faulty wiring connection.

If no malfunction is detected in the wiring:

-- Replace the Engine Control Module (ECM) 2 -J624-. Refer to ENGINE CONTROL MODULE, REMOVING AND INSTALLING .

Assembly is performed in the reverse order of removal.

-- Install the intake manifold. Refer to Intake Manifold .

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.