First of all check damage of harness and terminals : Check terminals for contact resistance, corrosion and deformation.
When glow plug is not heated although glow plug relay circuit is normal, Inspect the glow plug. If glow plug has a problem, engine hard starting occurs at cold starting or initial engine hesitation occurs after starting and exhaust fumes are discharged.
IG KEY "OFF", ENGINE "OFF"
Disconnect battery (-) terminal.
Remove EGR cooler and the parts related with EGR valve.
Remove glow plugs from the engine.
- Be sure not shocked to the ceramic tip of the glow plug.
- Do not use air power tool for removing (Installing) glow plugs.
Before measuring resistance, you must calibrate(0Ω) the tester.
"Multitester Calibration" of "Details Inspection(Equipment Setting)" reference
Measure the resistance between the terminal and body as below.
- The resistance value is very small, Inspect foreign substances on the glow plug meticulously.
Specification : 0.2 Ω ± 10% (20℃)
Case 1 : In case that resistance is high. (Open or over resistance)
Heating coil in the glow plug open
Replace the glow plug.
Case 2 : In case that resistance is low. (Short)
Heating coil in the glow plug short and fusible link is blown because of over current.
Replace the glow plug.
