ECD SYSTEM(w/o Glow Plug Controller) Pre-heating Control Circuit
| DTC Code | DTC Name |
|---|---|
| Pre-heating Control Circuit |
DESCRIPTION
The glow plug assemblies are mounted inside the engine combustion chamber. To ensure efficient engine starting with a cold engine, the ECM calculates a time interval during which current needs to flow through the glow plug assemblies, depending on the starting engine coolant temperature when the ignition switch is turned to ON. The ECM then turns on the glow plug relay assembly and permits the current to flow through the glow plug assemblies based on the ECM calculated time. The glow plug assemblies are then heated, and enhances fuel combustion with a cold engine.
These troubleshooting procedures are for: 1) difficult engine starting in cold weather, and 2) difficulty driving/vehicle malfunctions in cold weather immediately after engine is started.
After the engine is started, the ECM performs an "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.
Pre-glow time depends on battery voltage and engine coolant temperature.
After-glow time depends on atmospheric pressure and engine coolant temperature.
WIRING DIAGRAM
CAUTION / NOTICE / HINT
Inspect the fuse for circuits related to this system before performing the following procedure.
When replacing the ECM, perform ECM Initialization and Registration.
After turning ignition switch off, waiting time may be required before disconnecting the cable from the negative (-) battery terminal. Therefore, make sure to read the disconnecting the cable from the negative (-) battery terminal notices before proceeding with work.
PROCEDURE
INSPECT GLOW PLUG RELAY ASSEMBLY
*a
Component without harness connected
(Glow Plug Relay Assembly)
Disconnect the glow plug relay assembly connector.
Measure the resistance according to the value(s) in the table below.
Standard Resistance
Tester Connection
Condition
Specified Condition
3 - 4
Battery voltage not applied
10 kΩ or higher
Battery voltage applied to terminals 1 - 2
Below 1 Ω
Result
Proceed to
OK
NG
NG REPLACE GLOW PLUG RELAY ASSEMBLY
INSPECT GLOW PLUG ASSEMBLY (RESISTANCE)
Inspect the glow plug assembly.
Result
Proceed to
OK
NG
CHECK GLOW PLUG ASSEMBLY (INSTALLATION)
Check the glow plug assembly installation.
Result
Proceed to
OK
NG
CHECK HARNESS AND CONNECTOR (GLOW PLUG RELAY ASSEMBLY - ECM)
Disconnect the glow plug relay assembly connector.
Disconnect the ECM connector.
Measure the resistance according to the value(s) in the table below.
Standard Resistance
Tester Connection
Condition
Specified Condition
A100-2 - B138-13 (GREL)
Always
Below 1 Ω
A100-2 or B138-13 (GREL) - Body ground
Always
10 kΩ or higher
Result
Proceed to
OK
NG
NG REPAIR OR REPLACE HARNESS OR CONNECTOR
CHECK HARNESS AND CONNECTOR (GLOW PLUG RELAY ASSEMBLY - EFI-MAIN RELAY)
Disconnect the glow plug relay assembly connector.
Turn the ignition switch to ON.
Measure the voltage according to the value(s) in the table below.
Standard Voltage
Tester Connection
Condition
Specified Condition
A100-1 - Body ground
Ignition switch ON
11 to 14 V
Result
Proceed to
OK
NG
NG REPAIR OR REPLACE HARNESS OR CONNECTOR
CHECK ECM POWER SOURCE CIRCUIT
Check the ECM power source circuit.
Result
Proceed to
OK
NG
NG REPAIR OR REPLACE HARNESS OR CONNECTOR
CHECK HARNESS AND CONNECTOR (GLOW PLUG RELAY ASSEMBLY - GLOW PLUG ASSEMBLY - BATTERY)
Disconnect the negative (-) battery terminal.
Disconnect the positive (+) battery terminal.
Disconnect the glow plug relay assembly connector.
Disconnect the glow plug wire.
Measure the resistance according to the value(s) in the table below.
Standard Resistance
Tester Connection
Condition
Specified Condition
A100-3 - B128-1
Always
Below 1 Ω
A100-4 - Battery positive terminal
Always
Below 1 Ω
Result
Proceed to
OK
NG
NG REPAIR OR REPLACE HARNESS OR CONNECTOR