Positive Crankcase Ventilation Heating Element Checking

Special tools and workshop equipment required 

• Multimeter.
• Wiring diagram.

Test requirements 

• Fuse -SA1- OK.
• Fuse -SA5- OK.
• Fuse -SC1- 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 connections between engine/transmission/chassis OK.
• Ignition switched off.
• Engine cold.

Test procedure 

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

Start diagnosis 

-- Disconnect the Positive Crankcase Ventilation (PCV) Heating Element -N79- electrical harness connector.

-- Using a multimeter, check the Positive Crankcase Ventilation (PCV) Heating Element -N79- terminals 1 to 2 for resistance.

Specified value: 25 to 35 Ω (at approx. 20°C)

If the specified value was not obtained:

-- Replace the Positive Crankcase Ventilation (PCV) Heating Element -N79-.

If the specified value was obtained:

Checking voltage 

Switch the ignition On.

-- Using a multimeter, check the Positive Crankcase Ventilation (PCV) Heating Element -N79- electrical connector terminal 1 to Ground for voltage.

Specified value: Battery voltage.

Switch the ignition Off.

If the specified value was Not obtained:

-- Check the wiring from the Positive Crankcase Ventilation (PCV) Heating Element -N79- electrical connector terminal 1 to the Battery positive for an open circuit, high resistance, or a short circuit to Ground.

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

-- If necessary, repair the wiring connection.

If the specified value was obtained:

Checking Ground 

-- Using a multimeter, check the Positive Crankcase Ventilation (PCV) Heating Element -N79- electrical connector terminal 2 to Ground for resistance.

Specified value: 1.5 Ω Max.

If the specification was Not obtained:

-- Check the wiring for an open circuit, high resistance, a short circuit to each other, Battery or Ground.

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

-- If necessary, repair the faulty wiring connection.

If the specification was obtained:

-- Replace the Positive Crankcase Ventilation (PCV) Heating Element -N79-.

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 .