DTC 14 (4) Timing Control System Malfunction
DESCRIPTION
The ECM controls the injection timing by actuating the timing control valve. The timing control valve is mounted on the injection pump and controls the internal fuel pressure of the pump through duty control.
The ECM detects the injection advance angle based on TDC and NE signals.
| DTC No. | DTC Detection Condition | Trouble Area |
| 14 (4) |
During and after warming up the engine, the actual injection timing is different from the target value that the ECM calculated for several seconds. |
Open or short in timing control valve circuit
Timing control valve
Fuel filter element assembly (clogging)
Fuel (frozen, air present)
Injection pump assembly (internal pressure and timing control valve)
ECM
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WIRING DIAGRAM
INSPECTION PROCEDURE
| 1.INSPECT TIMING CONTROL VALVE |
Inspect the timing control valve (See page ).
| | REPLACE TIMING CONTROL VALVE
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| 2.CHECK ECM (TCV VOLTAGE) |
Disconnect the ECM connector.
Turn the ignition switch to ON.
Measure the voltage according to the value(s) in the table below.
- Standard Voltage:
| Tester Connection | Switch Condition | Specified Condition |
| C101-11 (TCV) - Body ground | Ignition switch ON | 11 to 14 V |
Text in Illustration| *a | Rear view of wire harness connector
(to ECM) |
Reconnect the ECM connector.
| 3.CHECK ECM (TCV VOLTAGE, SIGNAL) |
Turn the ignition switch to ON.
Measure the voltage according to the value(s) in the table below.
- Standard Voltage:
| Tester Connection | Switch Condition | Specified Condition |
| C101-11 (TCV) - C101-14 (E1) | Ignition switch ON | 11 to 14 V |
While idling, check the waveform according to the value(s) in the table below.
- OK:
| Tester Connection | Condition | Specified Condition |
| C101-11 (TCV) - C101-14 (E1) | Idling | Correct waveform is as shown |
Text in Illustration| *a | Component with harness connected
(ECM) |
| *b | TCV Signal Waveform |
| 4.CHECK LEVEL WARNING SWITCH |
Check the level warning switch (See page ).
| | REPLACE LEVEL WARNING SWITCH
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Visually check the injection pump, each injector and the fuel line for fuel leaks.
| | REPAIR OR REPLACE PART WITH FUEL LEAKAGE |
|
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| OK | |
| |
| REPLACE INJECTION PUMP ASSEMBLY
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| 6.CHECK TIMING CONTROL VALVE (POWER SOURCE) |
Disconnect the timing control valve connector.
Turn the ignition switch to ON.
Measure the voltage according to the value(s) in the table below.
- Standard Voltage:
| Tester Connection | Switch Condition | Specified Condition |
| C108-1 - Body ground | Ignition switch ON | 11 to 14 V |
Text in Illustration| *a | Front view of wire harness connector
(to Timing control valve) |
Reconnect the timing control valve connector.
| OK | |
| |
| REPAIR OR REPLACE HARNESS OR CONNECTOR (TIMING CONTROL VALVE - ECM) |
|
| 7.CHECK HARNESS AND CONNECTOR (TIMING CONTROL VALVE - NO. 1 INTEGRATION RELAY (EFI)) |
Disconnect the timing control valve connector.
Disconnect the No. 1 integration relay (EFI) connector from the engine room junction block.
Measure the resistance according to the value(s) in the table below.
- Standard Resistance (Check for Open):
| Tester Connection | Condition | Specified Condition |
| C108-1 - 1B-4 | Always | Below 1 Ω |
- Standard Resistance (Check for Short):
| Tester Connection | Condition | Specified Condition |
| C108-1 or 1B-4 - Body ground | Always | 10 kΩ or higher |
Reconnect the timing control valve connector.
Reconnect the No. 1 integration relay (EFI) connector.
| | REPAIR OR REPLACE HARNESS OR CONNECTOR |
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| OK | |
| |
| CHECK ECM POWER SOURCE CIRCUIT
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