Never connect glow plug directly to car battery to test the heating performance of the glow plug. It causes damage to the glow plug.
Before removing glow plug to inspect it, be sure to check that glow plug fuse (in the engine compartment fuse & relay box) is properly connected in place. If starting the engine with the glow plug fuse improperly connected, it causes damage to the glow plug.
"Be sure to check that the engine coolant temperature is below 30°C prior to inspection. If the coolant temperature is above 30°C, incorrect resistance of the glow plug may be measured."
Remove oil from plug before measuring as glowplug resistance is very small.
Remove the glow plug
(Refer to Engine Electrical System - "Glow Plug")
Check the continuity between the terminal and body as illustrated. Replace if discontinuity or with very small or large resistance.
State | Resistance (Ω) | |
Normal | 0.25 ~ 5 [15 ~ 25 °C (59 ~ 77 °F)] | |
Open | Over 5 [15 ~ 25 °C (59 ~ 77 °F)] | |
Short | Below 0.25 [15 ~ 25 °C (59 ~ 77 °F)] | |
