P269F: Exhaust Aftertreatment Glow Plug Circuit / Open

What it means

The aftertreatment glow plug element itself is open. No current flows even with the relay closed.

At a glance

• Usually lights the check-engine light

How it works

The aftertreatment glow plug is a heater in the exhaust path on some diesels; it helps ignite injected hydrocarbons during DPF regeneration. P269F indicates the module detects an open glow plug element circuit, so current cannot pass through the heater even when its relay is closed.

Common causes

Most likely first.

1. Glow element burnt out from age or HC overload
2. Corroded terminal at the plug body

Symptoms

• Check-engine light
• DPF warning light
• More frequent or unsuccessful DPF regeneration

How to diagnose it

1. Check freeze-frame data and regeneration status to see whether the open element was detected during a heater command.
2. Inspect the glow plug body terminal and connector for corrosion, looseness, or heat damage.
3. Check the glow plug element's continuity with power isolated according to the manufacturer's procedure.
4. If the element is open, verify that the connector and short lead are not the actual break before replacing the plug.
5. If element continuity is present, check relay output and the supply path under load against the manufacturer's specification.

Common fixes

• Clean and secure a serviceable corroded glow plug terminal.
• Repair a broken connector lead or damaged terminal.
• Replace the aftertreatment glow plug if its element is open.
• Repair a faulty relay or supply connection if the plug itself tests correctly.

Can I keep driving?

You can generally drive gently if the engine runs normally, but avoid repeated short trips and heed DPF warnings because regeneration may fail. Continued soot accumulation can eventually restrict the exhaust.