Complaint/Problem	Possible cause	Test step/Remedy 1)
Preglow indicator lamp does not light with glow/starter switch ON, engine can be started.	Preglow indicator lamp. Open or short circuit in wiring.	24 1.0
Preglow indicator lamp lights constantly.	Preglow time-limit relay module (N14) binding.	N14
Preglow indicator lamp does not light, engine can not be started.	Preglow time-limit relay module (N14). Voltage supply to preglow time-limit relay module (N14) is missing.	24 2.0 + 3.0
Preglow indicator lamp does not light with glow/starter switch ON or lights for approx. 1 minute while driving. Engine is hard to start.	Open circuit in one or several glow plugs or wires to glow plugs. Current draw of glow plugs not in order. Preglow indicator lamp	24 3.0
Preglow time until preglow indicator lamp goes out is too short or too long	ECT sensor (B11/8). Wires to ECT sensor (B11/8).	24 4.0

1) Observe Preparation for Test, see 22 .

Note regarding preglow circuit: An electronic short circuit protection feature is installed in the preglow time-limit relay module. If a short circuit occurs in the glow plugs or the wires to the glow plugs, the current is interrupted. The preglow time-limit relay module is again operational if the short circuit is eliminated and the glow/starter switch is turned to position "0". A malfunction of a glow plug is not indicated by the preglow indicator lamp.