Automatic Glow Time Control Module - J179- AND GLOW PLUG, Checking: Notes

General Description 

The glow plugs are activated by the Engine Control Module -J623- through The Automatic 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.

Special Tools And Workshop Equipment Required 

• Multimeter.
• Wiring Diagram.
• Scan Tool.

Test Requirements 

• Fuses OK.
• Battery voltage OK.
• Switch OFF all electrical and electronic accessories.
• Vehicles with Auto. Transmission, ensure Selector Lever position is in "P".
• Vehicles with Man. Transmission, ensure Shifter Lever position is in "N" with Parking Brake applied.
• Coolant Temperature: < 18° C.
• Observe all safety precautions: SAFETY PRECAUTIONS .
• View clean working conditions: CLEAN WORKING CONDITIONS .
• For Hybrid vehicles refer to: HIGH VOLTAGE SYSTEM GENERAL WARNINGS .