Possible causes

– Faulty cylinder #4 glow plug
– Cylinder #4 glow plug harness is open or shroted
– Cylinder #4 glow plug circuit poor electrical connection
– Faulty glow plug module

When is the code detected?

The Engine Control Module (ECM) has detected a fault in the cylinder #4 glow plug circuit

Symptoms

– Engine Light ON (or Service Engine Soon Warning Light)
– Lack/Loss of Power
– The engine may be harder to start
– Engine hesitation