6.
When the voltage or continuity time is not normal, check the terminal voltage in glow control unit, and single parts.
Conditions before inspection :
Battery voltage : 12V
Cooling water temperature : Below 30℃ (86°F)
(Disconnect the water temperature sensor connector).
Reconnect the water temperature sensor connector after inspection.
Connect voltmeter between glow plug plate and plug body (ground).
Check indicated value on voltmeter with ignition switch ON.
Check that preheat indication lamp lights for about 6 seconds and indicates battery voltage (about 9V or over) for about 20 seconds immediately after ignition switch is turned on. [At cooling water temperature 20°C (68.0°F)]
Continuity time varies depending upon cooling water temperature.
After checking 3, set ignition switch at START position.
The system is normal if battery voltage (about 9V or over) is generated for about 6 seconds during engine cranking and after start operation. [at cooling water temperature 20°C (68.0°F)]
When the voltage or continuity time is not normal, check the terminal voltage in glow control unit, and single parts.
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.
Check the continuity between the terminal and body as illustrated. Replace if discontinuity or with very small or large resistance.
Standard value
Ceramic : 0.31Ω
Metal : 0.35Ω
State | Resistance |
Short | Below 100mΩ |
Open | Over 1Ω |
Remove oil from plug before measuring as glowplug resistance is very small.
Check for rust on glow plug plate.
Check glow plug for damage.
The vehicle with NHTC glow plugs (ceramic heating element, beige insulator) should be equipped with black glow plug relay unit.
The vehicle with AQGS glow plugs (metal coil heating element, black insulator) should be equipped with gray glow lug relay unit.
Remove the glow plug relay after disconnecting it from wire harness.
Check open / short at each point of the glow plug relay by using multi meter (1MΩ range).
Check open / short between terminals 87 and 31.
State | Open / short criteria | Remedy |
Short / Open | Out the range of 350kΩ ± 30% | Change the glow plug relay |
Not Short / Open | In the range of 350kΩ ± 30% | Go to next step |
Check open / short between terminals G and 30.
Connect (+) rod to 30 terminal and (-) rod to G terminal.
State | Open / short criteria | Remedy |
Short / Open | Out the range of 100kΩ ± 30% | Change the glow plug relay |
Not Short / Open | In the range of 100kΩ ± 30% | Go to next step |
Connect (+) rod to G terminal and (-) rod to 30 terminal.
State | Open / short criteria | Remedy |
Short / Open | Out the range of 100kΩ ± 30% | Change the glow plug relay |
Not Short / Open | In the range of 100kΩ ± 30% | o.k |
Install the glow plug relay and then connect wiring harness to it.
