Cooling Fan 1, 2 Control Circuit Checking

Special tools and workshop equipment required 

• Multimeter.
• Test lamp
• Wiring diagram.

Test requirements 

• The Cooling Fan Module fuse S1 for J293 or S2 for J671 and S10 (for both modules) are OK.
• Battery voltage at least 12.5 V.
• All electrical consumers switched off.
• A/C switched off.
• The ignition switched OFF.

Test procedure 

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

Start diagnosis 

-- Disconnect the Cooling Fan Control Module -J293 or J671- electrical harness connector.

Checking voltage supply 

Switch the ignition ON.

-- Using a multimeter, check the Cooling Fan Control Module -J293 or J671- harness connector terminal 1 to ground for voltage.

-- Using a multimeter, check the Cooling Fan Control Module -J293 or J671- harness connector terminal 2 to ground for voltage.

Specified value for both terminals: Battery voltage.

Switch the ignition OFF.

If the specified value was Not obtained at Terminal 1 of the Cooling Fan Control Module:

-- Check the wiring from the Cooling Fan Control Module -J293 or J671- harness connector terminal 1 to fuse S1 (for J293) or S2 (for J671) for high resistance, open or short to ground.

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

-- If necessary, repair the wiring connection and replace any blown fuse.

If the specified value was Not obtained at Terminal 2 of the Cooling Fan Control Module:

-- Check the wiring from the Cooling Fan Control Module -J293 or J671- harness connector terminal 2 to fuse S10 for high resistance, open or short to ground.

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

-- If necessary, repair the wiring connection and replace any blown fuse.

If the specified value was obtained:

-- Connect a test lamp to Battery positive. Connect the other end to terminal 4 of the Cooling Fan Control Module -J293 or J671- harness connector.

Switch the ignition ON.

Specified value: Test lamp is ON.

Switch the ignition OFF.

If the specified value was Not obtained:

-- Check the ground circuit for an open or high resistance.

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

-- If necessary, repair the faulty wiring connection.

If the specified value was obtained:

Switch the ignition ON.

-- Using a multimeter, check the Cooling Fan Control Module -J293 or J671- harness connector terminal 3 to ground for voltage.

Specified value: 0.330 to 0.360 V.

Switch the ignition OFF.

If the specified value was obtained:

-- Replace the Cooling Fan Control Module -J293 or J671-. Refer to the Repair Information.

If the specified value 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 Cooling Fan Control Module --N112-- harness connector terminal 3 to the Engine Control Module (ECM) -J623- electrical harness connector T121 for high resistance, short to ground or voltage, or an open circuit.

Cooling Fan Control Module 1 -J293- electrical harness connector terminal	Engine Control Module (ECM) -J623- electrical connector T94 terminal or test box socket
3	28

OR 

Cooling Fan Control Module 2 -J671- electrical harness connector terminal	Engine Control Module (ECM) -J623- electrical connector T94 terminal or test box socket
3	30

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 or voltage.

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

-- If necessary, repair the faulty wiring connection.

If no malfunction is detected in the wiring:

-- 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 .