TROUBLESHOOTING E306

Service Code in Electrical System E306 (Abnormality in governor potentiometer)

User Code Service Code Failure Code Failure Abnormality in governor potentiometer
— E306 DK54KZ phenomenon (in governor • pump controller)
Failure content • Signal voltage from the governor potentiometer dropped below 0.4 V or exceeded 4.6 V.
• The controller exercises control by computing the motor position through voltage right before a failure
Response from occurred.
controller • Even if the failure cause disappears of itself, the governor potentiometer does not return to normalcy,
unless the engine starting switch is once turned OFF.
• The engine cannot attain the specified rotation at high idling. (A bit lower)
• The engine cannot attain the specified rotation at low idling (A bit higher)
Phenomenon
• The auto-decelerator or automatic warming-up function does not work.
occurring on
• There is hunting while the engine is running.
machine
• The engine stalls.
• The engine does not stop.
Relative • Input from the governor potentiometer (voltage) can be confirmed in the monitor function.
information (Code No. 031: Governor potentiometer voltage)

Cause Standard value in normalcy and references for troubleshooting

Sensor power source
1 If Service Code No. [E226] is displayed, troubleshoot the failure first.
defective
a Turn the engine starting switch OFF for the preparations, and hold it in the OFF posi-
tion during the troubleshooting.
Governor potentiometer E10 (male) Resistance value
2 defective
Between (A) and (C) 4.0 – 6.0 kz
(Internal failure)
Between (B) and (A) 0.25 – 5.0 kz
Between (B) and (C) 0.25 – 5.0 kz
Presumed cause and standard value in normalcy

a Turn the engine starting switch OFF for the preparations, and hold it in the OFF posi-
tion during the troubleshooting.
Disconnection of wiring Wiring harness from C01 (female) (22) to J07 to E10 Resistance
harness Max. 1 z
(female) (A) value
3 (Disconnection or defec-
tive contact with connec- Wiring harness between C01 (female) (21) and E10 Resistance
Max. 1 z
tor) (female) (C) value
Wiring harness between C01 (female) (13) and E10 Resistance
Max. 1 z
(female) (B) value
Grounding fault of wiring a Turn the engine starting switch OFF for the preparations, and hold it in the OFF posi-
harness tion during the troubleshooting.
4
(Contact with grounding Between wiring harness between C01 (female) (13) and Resistance
circuit) Min. 1 Mz
E10 (female) (B) and grounding value
a Turn the engine starting switch OFF for the preparations, and hold it in the ON position
Short-circuiting of wiring during the troubleshooting.
harness Between wiring harness from C01 (female) (22) to J07 to
5 Voltage Max. 1 V
(Contact with 24 V cir- E10 (female) (A) and grounding
cuit) Between wiring harness between C01 (female) (13) and
Voltage Max. 1 V
E10 (female) (B) and grounding
a Turn the engine starting switch OFF for the preparations, and hold it in the ON position
during the troubleshooting.
Governor • pump C01 Resistance value
6
controller defective
Between (22) and (21) Power supply 4.5 – 5.5 V
Between (13) and (21) Signal 0.5 – 4.5 V

20-364 PC200/220(LC)-7
(5)
TESTING AND ADJUSTING E306

Electrical Circuit Diagram for Governor Motor in Governor • Pump Controller

PC200/220(LC)-7 20-365