Ecd System Pre-Heating Control Circuit
DESCRIPTION
WIRING DIAGRAM
INSPECTION PROCEDURE
CHECK TERMINAL VOLTAGE (GLOW PLUG RELAY(GLOW))
INSPECT GLOW PLUG RELAY(GLOW)
INSPECT GLOW PLUG (RESISTANCE)
CHECK GLOW PLUG (INSTALLATION)
CHECK WIRE HARNESS (GLOW PLUG - GLOW PLUG RELAY(GLOW) - BODY GROUND)
CHECK WIRE HARNESS (GLOW PLUG RELAY(GLOW) - ECM AND BODY GROUND)
ECD SYSTEM - Pre-heating Control Circuit |
DESCRIPTION
The glow plug is mounted inside the engine combustion chamber. To ensure efficient engine starting with a cold engine, the ECM calculates the period of time that the current needs to flow through the glow plug depending on the starting engine coolant temperature when the ignition switch is turned to ON. The ECM then turns on the glow plug relay and permits the current to flow through the glow plug based on the time calculated by the ECM. The glow plug is then heated, and enhances fuel combustion with a cold engine. - HINT:
- These troubleshooting procedures are for: 1) difficulty starting the engine in cold weather, and 2) difficulty driving/vehicle malfunctions in cold weather immediately after the engine is started.
- After the engine is started, the ECM performs "after-glow" for a certain period of time. In proportion to the actual engine coolant temperature, the time period varies. The after-glow reduces diesel engine knocking, white smoke emissions and engine noises when the engine is cold.
WIRING DIAGRAM
INSPECTION PROCEDURE
- NOTICE:
- Inspect the fuses of circuits related to this system before performing the following inspection procedure.
- After replacing the ECM, the new ECM needs registration (LandCruiser RM0000012XK0ARX.html) and initialization (LandCruiser RM000000TIN08CX.html).
| 1.CHECK TERMINAL VOLTAGE (GLOW PLUG RELAY(GLOW)) |
Remove the glow plug relay (GLOW).
Measure the voltage according to the value(s) in the table below.
- Standard Voltage:
Tester Connection
| Switch Condition
| Specified Condition
|
Glow plug relay terminal-5 - Body ground
| Ignition switch ON
| 11 to 14 V
|
Text in Illustration*1
| Engine Room Relay Block
|
*2
| Glow Plug Relay (GLOW)
|
Reinstall the glow plug relay (GLOW).
| | REPAIR OR REPLACE HARNESS AND CONNECTOR (GLOW PLUG RELAY - BATTERY) |
|
|
| 2.INSPECT GLOW PLUG RELAY(GLOW) |
Inspect the glow plug relay (GLOW) (LandCruiser RM000003BIA03DX_01_0004.html).
| 3.INSPECT GLOW PLUG (RESISTANCE) |
Inspect the glow plug (LandCruiser RM0000044ZK00RX_01_0001.html).
| 4.CHECK GLOW PLUG (INSTALLATION) |
Check the glow plug installation.
- OK:
- Glow plugs are installed securely.
- Torque:
- 12.3 N*m{125 kgf*cm, 9 ft.*lbf}
| 5.CHECK WIRE HARNESS (GLOW PLUG - GLOW PLUG RELAY(GLOW) - BODY GROUND) |
Remove the glow plug relay (GLOW).
Disconnect the glow plug connector.
Measure the resistance according to the value(s) in the table below.
- Standard Resistance (Check for Open):
Tester Connection
| Condition
| Specified Condition
|
Glow plug relay terminal-3 - C98-1
| Always
| Below 1 Ω
|
Glow plug relay terminal-1 - Body ground
| Always
| Below 1 Ω
|
- Standard Resistance (Check for Short):
Tester Connection
| Condition
| Specified Condition
|
Glow plug relay terminal-3 or C98-1 - Body ground
| Always
| 10 kΩ or higher
|
Reinstall the glow plug relay (GLOW).
Reconnect the glow plug connector.
| | REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
|
| 6.CHECK WIRE HARNESS (GLOW PLUG RELAY(GLOW) - ECM AND BODY GROUND) |
Remove the glow plug relay (GLOW).
Disconnect the ECM connector.
Measure the resistance according to the value(s) in the table below.
- Standard Resistance (Check for Open):
Tester Connection
| Condition
| Specified Condition
|
Glow plug relay terminal-2 - C91-19 (GREL)
| Always
| Below 1 Ω
|
- Standard Resistance (Check for Short):
Tester Connection
| Condition
| Specified Condition
|
Glow plug relay terminal-2 or C91-19 (GREL) - Body ground
| Always
| 10 kΩ or higher
|
Reinstall the glow plug relay (GLOW).
Reconnect the ECM connector.
| | REPAIR OR REPLACE HARNESS OR CONNECTOR |
|
|
