DTC 13 (2) Engine Speed Sensor Circuit Malfunction
DESCRIPTION
The engine speed sensor in the engine control system contains a signal plate and a pickup coil for the NE signal. The NE signal plate has 56 teeth and is mounted in the injection pump. The NE signal sensor generates 56 signals for every 2 engine revolutions. The ECM detects the engine speed and cam lift position of the injection pump. The ECM uses the TDC and NE signals for injection timing control. The NE signal is also used for injection volume control.
| DTC No. | DTC Detection Condition | Trouble Area |
| 13 (2) |
No NE signal is sent to the ECM for 0.5 sec. or more at 680 rpm or more. | Open or short in engine speed sensor circuit
Engine speed sensor
ECM
|
| No NE signal is sent to the ECM for 2.0 sec. or more during cranking. |
WIRING DIAGRAM
Refer to DTC 12 (See page ).
INSPECTION PROCEDURE
| 1.INSPECT ENGINE SPEED SENSOR |
Inspect the engine speed sensor (See page ).
| | REPLACE INJECTION PUMP ASSEMBLY
|
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| 2.CHECK ECM (TDC, NE SIGNAL)
|
While cranking or idling, check the waveforms according to the value(s) in the table below.
- OK:
| Tester Connection | Condition | Specified Condition |
| C101-17 (TDC+) - C101-16 (TDC-) | Idling | Correct waveform is as shown |
| C101-19 (NE+) - C101-18 (NE-) | Idling | Correct waveform is as shown |
Text in Illustration| *a | Component with harness connected
(ECM) |
| *b | TDC and NE Signal Waveforms |
| 3.CHECK HARNESS AND CONNECTOR (ECM - ENGINE SPEED SENSOR) |
Disconnect the engine speed sensor connector.
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 |
| C103-2 (NE+) - C101-19 (NE+) | Always | Below 1 Ω |
| C103-1 (NE-) - C101-18 (NE-) | Always | Below 1 Ω |
- Standard Resistance (Check for Short):
| Tester Connection | Condition | Specified Condition |
| C103-2 (NE+) or C101-19 (NE+) - Body ground | Always | 10 kΩ or higher |
| C103-1 (NE-) or C101-18 (NE-) - Body ground | Always | 10 kΩ or higher |
Reconnect the engine speed sensor connector.
Reconnect the ECM connector.
| | REPAIR OR REPLACE HARNESS OR CONNECTOR |
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|
| OK | |
| |
| CHECK FOR INTERMITTENT PROBLEMS
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