108B0A

What Code 108B0A Means

Code 108B0A points to a fault in the crankcase ventilation heater circuit. The heater keeps condensate from freezing and forming emulsion in the crankcase ventilation lines, especially in cold weather. When it fails, the crankcase ventilation system doesn't work correctly, which leads to oil sludge buildup and higher emissions.

The crankcase ventilation (PCV) system routes blow-by gases back into the intake manifold for reburning. The heater in the ventilation circuit holds a temperature high enough to evaporate moisture and keep the passages from clogging. The engine control unit (DME) sets code 108B0A when it detects an open circuit, a short, or out-of-spec parameters in the heater circuit.

Affected components: the crankcase ventilation heater, its wiring and connector, and the engine control unit (DME), which monitors the heater.

Symptoms

• Check Engine light: the malfunction indicator lamp comes on in the instrument cluster.
• Rough idle: the engine may run unevenly, especially on a cold start or in low ambient temperatures.
• Higher oil consumption: disrupted crankcase ventilation can increase oil consumption.

Symptoms vary with operating conditions and the condition of the crankcase ventilation system.

Diagnosis and Repair

1. Read the fault codes with diagnostic equipment (ISTA, INPA) and confirm code 108B0A is present.
2. Visually inspect the crankcase ventilation heater and its wiring for damage, corrosion, opens, or shorts.
3. Check resistance of the heater with a multimeter against the manufacturer's specifications. Compare to the nominal value.
4. Check power and ground at the heater connector with the ignition on. Confirm voltage is present and the ground circuit is intact.
5. If the heater or its wiring is faulty, replace the bad component. Repair the wiring and connectors as needed.
6. After the repair, clear the fault codes and take a test drive to confirm the code doesn't return.

Tools needed: diagnostic scanner (ISTA, INPA), multimeter, electrical repair tool kit.

Secondary Problems

Ignoring a failed crankcase ventilation heater can lead to oil sludge buildup in the ventilation system, clogged passages, and as a result, higher crankcase pressure. That can push out seals and gaskets, cause oil leaks, and lead to more serious engine damage. Disrupted crankcase ventilation also raises emissions and lowers engine efficiency. Fix the fault promptly to avoid costly repairs.