Automatic Glow Time Control Module - J179- And Glow Plug, Checking: General Description

The glow plugs are activated by the Engine Control Module -J623- through theAutomatic Glow Time Control Module -J179-. The voltage on the individual glow plugs is adjusted over the frequency of the PWM impulses. For quick start with an ambient temperature of less than 64° F (18° C), a maximum voltage of 11.5 volts is present during preheating. This ensures that the glow plug heats up as quickly as possible (maximum two seconds) to over 1, 832° F (1, 000° C), thus reducing the preheating time of the engine. Post-heating is performed up to a coolant temperature of 64° F (18° C) after engine start for a maximum of five minutes. Post-heating helps reduce hydrocarbon emissions and combustion noise during the engine warm-up phase.