Diagnosis And Testing - Glow Plugs
CAUTION:
DO NOT attempt to start the engine until the glow plug system tests correctly.
CAUTION:
Do not apply 12 V battery voltage to the glow plug. Damage the glow plug, engine, or personal injury may result.
NOTE:
To ensure a good contact of the measurement connections the contacts have to be free of oil, dirt or corrosion.
- Measure the electrical resistance of each glow plug while it is still installed in the cylinder head. Resistance should be between 0.2 E 5? between the electrical connector point on the glow plug and the cylinder head. The ground contact on the DVOM must be as close as possible to the point where the glow plug contacts the cylinder head to avoid erratic resistance measurements.
- If the resistance is out of tolerance, remove the glow plug from the cylinder head and check the resistance again.
- Dismantled state: measure between connection side (connector/thread) and housing.
- Engine mounted state: measure between connection side (connector/thread) and engine mass.
- Resistance value:
- Resistance > 5 Ω: open circuit failure.
- Resistance < 200 mΩ: short circuit failure.
- 200 mΩ < Resistance < 5 Ω: glow plug OK.
- Use the actuator test function of the scan tool to test the glow plug module and glow plug lamp. The glow plug module's on-board diagnostic tests will automatically check the electrical condition of the entire glow plug system.
- After the scan tool glow plug actuator test function is complete, if MIL is OFF and no glow plug DTCs are present, testing is complete and the engine can be started.
- If MIL is still ON, check the harness connectors of glow plugs, repair any loose or damaged connections, and run the glow plug actuator test again.
- If MIL is still ON, check the electrical connectors of glow plugs and power up the glow plugs again.