DR ALL-TERRAIN Service Manual download pdf (Page 104)

3-40 FUEL SYSTEM (DFI)

Self-Diagnosis

Backups

○

The ECU takes the following measures to prevent engine damage when the DFI or the ignition

system parts have troubles.

Service

Codes

Parts

Output Signal Usable

Range or Criteria

Backups by ECU

Throttle

Sensor

Throttle Sensor Output

Voltage

0.2 ∼ 4.8 V

If the throttle sensor system fails (the signal is

out of the usable range, wiring short or open),

the ECU locks ignition timing into the ignition

timing at opened throttle position and sets the

DFI in the D-J method.

Also, the throttle sensor system and inlet air

pressure sensor fails, the ECU l ocks ignition

timing into the ignition timing at opened throttle

position and sets the DFI in the α-N method.

Inlet Air

Pressure

Sensor

Inlet Air Pressure Sensor

Output Voltage

0.2 ∼ 4.8 V

If the inlet air pressure sensor system fails (the

signal Pv is out of the usable range, wiring

short or open), the ECU sets the DFI in the α

-Nmethod.

Inlet Air

Temperature

Sensor

Inlet Air Temper

ature

Sensor Output Voltage

0.2 ∼ 4.6 V

If the inlet air temperature sensor fails (the

signal is out of the usable range, wiring short

or open), the ECU sets Ta at 30°C.

Water

Temperature

Sensor

Water Temperature

Sensor Output Voltage

0.2 ∼ 4.6 V

If the water temperature sensor system fails

(the signal is out of the usable range, wiring

short or open), the ECU sets Tw at 80°C.

Crankshaft

Sensor

Crankshaft sensor must

send 22 signals (output

signal) to the ECU at the

one cranking.

If crankshaft sensor does not generate signals,

the engine stops by itself.

24 Speed Sensor

Speed sensor must send

20 signals (output signal)

to the ECU at the one

rotation of the output

driven bevel gear.

If the speed sensor system fails (no signal,

wiring short or open), the speedometer shows

Vehicle-down

Sensor

Vehicle-down Sensor

Output Voltage

Vd = 0.2 ∼ 4.6 V

If the vehicle-down sensor system has failures

(the output voltage Vd is more than usable

range, wiring open), the ECU shuts off the fuel

pump.

Fuel Pump

Relay

When the relay ON

condition, battery monitor

voltage 5 V or more

If the relay fails, battery monitor voltage 12 V.

51 Ignition Coil #1

The ignition coil primary

winding must send

signals

(output voltage)

continuously to the ECU.

If the ignition primary winding #1 has failures

(no signal, wiring short or open), the ECU

shuts off the injector #1 to stop fuel to the

cylinder #1, though the engine keeps running.

Ignition Coil #2

The ignition coil primary

winding must send

signals (output voltage)

continuously to the ECU.

If the ignition primary winding #2 has failures

(no signal, wiring short or open), the ECU

shuts off the injector #2 to stop fuel to the

cylinder #2, though the engine keeps running.

Note:

(1) D-J Method and α - N Method: When the engine load is light like at idling or low speed, the ECU

determines the injection quantity by calculating from the throttle vacuum (inlet air pressure sensor

output voltage) and engine speed (crankshaft sensor output voltage). This method is called D-J

method (low-speed mode). As the engine speed increases, and the engine load turns middle to

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DR ALL-TERRAIN Service Manual Page 104

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