Normal Operation - Diesel Engine; Cold Weather Precautions - Jeep Grand Cherokee 2017 Manual

26 STARTING AND OPERATING
NORMAL OPERATION — DIESEL ENGINE
Observe the following when the diesel engine is operating.
• All message center lights are off.
• Malfunction Indicator Light (MIL) is off.
• Engine Oil Pressure telltale is not illuminated.
• Voltmeter operation:
The voltmeter may show a gauge fluctuation at various
engine temperatures. This is caused by the glow plug
heating system. The number of cycles and the length of the
cycling operation is controlled by the engine control mod-
ule. Glow plug heater operation can run for several min-
utes, once the heater operation is complete the voltmeter
needle will stabilize.

Cold Weather Precautions

Operation in ambient temperature below 32°F (0°C) may
require special considerations. The following charts sug-
gest these options: