OBD-II fault code

P06BD: Cylinder 5 Glow Plug Circuit Range or Performance

What it means

The cylinder 5 glow plug circuit is not performing within the expected range. The cause may be the glow plug, its wiring or connections, or the control circuit.

At a glance

  • Usually lights the check-engine light
  • Affects emissions; the car can fail an emissions test

How it works

The cylinder 5 glow plug warms the combustion chamber for diesel cold starting. P06BD sets when the control module finds the cylinder 5 glow plug circuit is performing outside its expected range.

Common causes

Most likely first.

  1. Faulty glow plug
  2. Damaged or corroded wiring or connector
  3. Glow plug control circuit fault

Symptoms

  • Glow plug warning light on (often orange coil symbol)
  • Hard cold start or no start in cold weather
  • White smoke from exhaust during warm-up

How to diagnose it

  1. Record freeze-frame data and note ambient and engine temperature, since the fault may be most apparent during cold-start preheating.
  2. Inspect the cylinder 5 glow plug connector and wiring for corrosion, looseness, heat damage, or chafing.
  3. With the ignition off and following the vehicle's service procedure, compare cylinder 5 glow plug resistance with the manufacturer's specification and with the other plugs.
  4. Check the cylinder 5 circuit for continuity and unwanted shorts, and verify the glow plug control unit supplies the circuit as specified.
  5. If wiring and supply are sound, test or remove the cylinder 5 glow plug using the specified procedure and replace it if it fails.

Common fixes

  • Reconnect or clean the cylinder 5 glow plug connector.
  • Repair damaged wiring in the cylinder 5 glow plug branch.
  • Replace the cylinder 5 glow plug if its test result is outside specification.
  • Repair or replace the glow plug control unit if testing confirms it is not controlling the cylinder 5 circuit correctly.

Can I keep driving?

The vehicle may start and run poorly in cold weather, with white smoke during warm-up; avoid repeated long cranking, which can drain the battery and stress the starter. Arrange repair soon, especially if cold starting becomes unreliable.

A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together

This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.