P269D: Exhaust Aftertreatment Glow Plug Control Circuit Low

A low reading on the exhaust glow plug control line points to a path to ground before the load, so the control stage cannot set the right level and the vaporizer glow plug may be switched wrongly. Ford is the documented user: in its 2017 and 2018 diesel summaries the 3.2 L Transit judges the downstream injection glow plug circuit by voltage windows, and a reading held between 1.95 and 2.175 V for 5 s is classed as a short to ground (key on, battery 9–16.3 V). In 2015 and 2016 Ford used P2688 for the identical window. Typical findings are a pinched wire near the exhaust or a shorted relay coil. The DPF regeneration that relies on vaporized fuel is held back until the circuit is repaired.

Low severity. Can I keep driving?You can keep driving, although cold starts will be harder. Avoid cranking the starter repeatedly on cold days.

Symptoms

MIL on
Regeneration suspended, rising soot load
Possible blown fuse in the glow plug feed

Most likely causes

Control wire chafed on the exhaust or body and grounded
Shorted coil in the glow plug relay
Heat-damaged connector near the vaporizer

What to check, in order

Start with the simplest. You can tick off each step.

Check the fuse and connector
With the connector unplugged, check whether the signal wire is making contact with ground.
Measure the resistance of each glow plug with the engine cold
Check the power supply during the preheat cycle
Test the module or relay if the glow plugs are good

Good to know

Repair difficulty: medium
It affects emissions.

What each character of P269D means

P: Powertrain: engine and transmission
2: Generic code: same on every make
6: Control modules and outputs
9D: Specific fault in that system

Frequently asked questions

Can I keep driving with code P269D?

You can keep driving, although cold starts will be harder. Avoid cranking the starter repeatedly on cold days.

What causes code P269D?

The most common causes are: control wire chafed on the exhaust or body and grounded; shorted coil in the glow plug relay; heat-damaged connector near the vaporizer.

Related codes

Sources

Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.