Glow Plugs, Checking

Special tools and workshop equipment required 

• Multimeter.
• Diode test lamp.
• Wiring diagram.

Test requirements 

• Fuse -S39- OK.
• The Glow Plug Relay -J52- OK.
• Battery voltage at least 12.5 volts.
• Ground (GND) connections between engine/transmission/chassis OK.
• Ignition switched off.

Test procedure 

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

Start diagnosis 

-- Disconnect the Engine Coolant Temperature (ECT) Sensor -G62- electrical harness connector -1-.

Checking voltage supply 

-- Disconnect the Glow Plug -- electrical connectors.

-- Using a Multimeter, check each Glow Plug -- electrical connector, in sequence, from 1 to 4, to Ground (GND) for voltage.

Specified value: Battery voltage for 20 seconds.

If the specified value is not obtained:

-- Using a Multimeter, check each Glow Plug -- electrical harness to the Glow Plug Relay -J52- socket 4 & 6 for resistance.

Specified value: 1.5 Ω Max.

If the specification was not obtained:

-- Check the wiring from the Glow Plug -- electrical harness to the Glow Plug Relay -J52- socket 4 & 6 for an open circuit, short circuit to each other or to Battery (+) or Ground (GND).

-- 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 the voltage supply was not OK:

-- Check the Glow Plug Relay -J52-. Refer to GLOW PLUG RELAY, CHECKING .

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

Checking Glow Plug 

-- Using a Diode test lamp, check the Glow Plug -- from Battery (+) to each individual Glow Plug --.

The Diode test lamp must light up.

If the Diode test lamp does not light up:

-- Replace the faulty Glow Plug --.

-- Perform a road test to verify repair.

If the fault does not return:

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

-- End diagnosis.

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

-- Recheck the voltage supply.

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

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 .

End diagnosis.