(Komatsu forklifts – error codes / diagnostic trouble codes)
ALA-5206 – The key switch is turned ON when the lift lever is in the position other than neutral.
Remedy: Return the lift lever to neutral position, turn off the key switch then turn it on again. (If not recovered proceed as follow)
Symptom of vehicle
– The lift only is inoperable.
– When turning ON the key, the error appears immediately.
Cause of trouble
– The lift lever sensor is improperly adjusted.
– The lift lever sensor is defective.
– The harness of lift lever sensor circuit is defective.
– Fuse 20 or 21 is defective.
Repair Procedure
1. Confirm that the lift lever sensor signal is input. Measure the voltage between terminals 3 and 2 of connector CS1S. Normal Value: 2.39 – 2.61V
2. If the voltage is normal in step 1, replace the proportional solenoid valve controller board.
4. If the voltage is abnormal in step 1, check the harness between lever sensor and proportional solenoid valve controller and repair it, or check fuse 20 or 21 and change the fuse (2A).
5. If the voltage is abnormal in step 1 and the harness is normal in step 3, repair the lever sensor.
Remark: When 5292 and 5294 are simultaneously displayed, check these codes first.
For remedy, refer to the item of each trouble code.
Condition of abnormal detection:
Lever sensor neutral output voltage
Other than 2.14 – 2.82V.
ALA-5207 – The key switch is turned ON when the tilt lever is in the position other than neutral.
Remedy: Return the lift lever to neutral position, turn off the key switch then turn it on again. (If not recovered proceed as follow)
Symptom of vehicle
– The tilt only is inoperable.
– When turning ON the key, the error appears immediately.
Cause of trouble
– The tilt lever sensor is improperly adjusted.
– The tilt lever sensor is defective.
– The harness of tilt lever sensor circuit is defective.
– Fuse 22 or 23 is defective.
Repair Procedure
1. Confirm that the lift lever sensor signal is input. Measure the voltage between terminals 4 and 2 of connector CS1S. Normal Value: 2.39 – 2.61V
2. If the voltage is normal in step 1, replace the proportional solenoid valve controller board.
3. If the voltage is abnormal in step 1, check the harness between lever sensor and proportional solenoid valve controller and repair it, or check fuse 22 or 23 and change the fuse (2A).
4. If the voltage is abnormal in step 1 and the harness is normal in step 3, repair the lever sensor.
Remark: When 5292 and 5294 are simultaneously displayed, check these codes first.
For remedy, refer to the item of each trouble code.
Condition of abnormal detection:
Lever sensor neutral output voltage
Other than 2.14 – 2.82V.
ALA-5208 – The key switch is turned ON when the ATT 1 lever is in the position other than neutral.
Remedy: Return the ATT 1 lever to neutral position, turn off the key switch then turn it on again. (If not recovered proceed as follow)
Symptom of vehicle
– The ATT 1 only is inoperable.
– When turning ON the key, the error appears immediately.
Cause of trouble
– The ATT 1 lever sensor is improperly adjusted.
– The ATT 1 lever sensor is defective.
– The harness of ATT 1 lever sensor circuit is defective.
– Fuse 24 or 25 is defective.
Repair Procedure
1. Confirm that the ATT 1 lever sensor signal is input.
Measure the voltage between terminals 5 and 2 of connector CS1S. Normal Value: 2.39 – 2.61V
2. If the voltage is normal in step 1, replace the proportional solenoid valve controller board.
3. If the voltage is abnormal in step 1, check the harness between lever sensor and proportional solenoid valve controller and repair it, or check fuse 24 or 25 and change the fuse (2A).
4. If the voltage is abnormal in step 1 and the harness is normal in step 3, repair the lever sensor.
Remark : When 5292 and 5294 are simultaneously displayed, check these codes first.
For remedy, refer to the item of each trouble code.
Condition of abnormal detection:
Lever sensor neutral output voltage
Other than 2.14 – 2.82V.
ALA-5209 – The key switch is turned ON when the ATT 2 lever is in the position other than neutral.
Remedy: Return the ATT 2 lever to neutral position, turn off the key switch then turn it on again. (If not recovered proceed as follow)
Symptom of vehicle
– The ATT 2 only is inoperable.
– When turning ON the key, the error appears immediately.
Cause of trouble
– The ATT 2 lever sensor is improperly adjusted.
– The ATT 2 lever sensor is defective.
– The harness of ATT 2 lever sensor circuit is defective.
– Fuse 26 or 27 is defective.
Repair Procedure
1. Confirm that the ATT 2 lever sensor signal is input. Measure the voltage between terminals 6 and 2 of connector CS1S. Normal Value: 2.39 – 2.61V
2. If the voltage is normal in step 1, replace the proportional solenoid valve controller board.
3. If the voltage is abnormal in step 1, check the harness between lever sensor and proportional solenoid valve controller and repair it, or check fuse 26 or 27 and change the fuse (2A).
4. If the voltage is abnormal in step 1 and the harness is normal in step 3, repair the lever sensor.
Remark: When 5292 and 5294 are simultaneously displayed, check these codes first.
For remedy, refer to the item of each trouble code.
Condition of abnormal detection:
Lever sensor neutral output voltage
Other than 2.14 – 2.82V.
ALA-5229 – The tilt automatic horizontal stops before or after the completion position.
Remedy: Return the tilt lever to neutral position and turn off the tilt horizontal button. (If not recovered proceed as follow)
Symptom of vehicle
– The tilt horizontal stops before or after the completion position. (Manual operation is possible.)
Cause of trouble
– Mechanical trouble.
Repair Procedure
It is not abnormal. But if the symptom appears frequently, check and repair the mechanical cause that hinders the movement.
Remark: Condition of abnormal detection: It is shifted from the horizontal position.
ALA-5255 – The tilt automatic horizontal is operated incorrectly.
(Manual operation is possible.)
Content of Detection
Case 1: Wrong operation
When in tilt back position, push the tilt switch and pull tilt lever.
When fork is already horizontal, push tilt switch and pull or push tilt lever.
When fork is in forward position, push tilt switch and push tilt lever.
Case 2: When cargo is loaded, push the tilt switch and try to fork horizontal position. This option only works with empty load condition. If load is empty and truck still displays the error code, the hydraulic pressure sensor or its wire may be damaged.
Case 3: Shorted tilt switch. When the tilt switch is shorted, the tilt horizontal function is actuated. In this case, carry out CASE 1 operation. Error is always displayed.
ACTION TO BE TAKEN
Connect PC and start analyzer software; then observe the tilt switch function and hydraulic pressure value at monitor screen.
Remedy:
– Operate the tilt lever in the horizontal direction
– Set the tilt lever in other than horizontal position and operate the automatic horizontal.
– Unload the cargo and operate the automatic horizontal without load
(If not recovered proceed as follow)
Symptom of vehicle
– The tilt automatic horizontal operation cannot be performed.
Cause of trouble
– The lever is operated in the reverse direction.
– The automatic horizontal operation is performed when placed in the horizontal position.
– The automatic horizontal operation is performed with loaded forks.
Repair Procedure
Operate correctly.
Remark: If 5207, 5216, 5217 and 5219 are simultaneously displayed, check these codes first.
For remedy, refer to the item of each trouble code.
Condition of abnormal detection:
When the lever is reversely operated:
– Automatic operation is performed when placed in the horizontal position.
– Automatic operation is performed with loaded forks.
ALA-5255 – The tilt automatic horizontal is incorrectly operated.
(Manual operation is impossible.)
1) The tilt lever is reversely operated.
2) The automatic horizontal operation is performed when the tilt lever is in the horizontal position.
3) The automatic horizontal operation is performed with the cargo loaded.
Remedy:
– Operate the tilt lever in the horizontal direction
– Set the tilt lever in other than horizontal position and operate the automatic horizontal.
– Unload the cargo and operate the automatic horizontal without load
(If not recovered proceed as follow)
Symptom of vehicle
– The tilt automatic horizontal operation cannot be performed.
Cause of trouble
– The tilt horizontal button is shorted.
– The tilt horizontal harness is shorted.
Repair Procedure
1) Operate the tilt horizontal button and confirm that the automatic horizontal display lights (or blinks) / goes off. If normal, replace the proportional solenoid valve controller board.
2) If the automatic horizontal display is abnormal in step 1, remove the tilt horizontal button connector and check the resistance of button. If abnormal, replace the button.
Normal Resistance Value:
Between terminals 1 and 2
– Button ON: 0Ω
– Button OFF: cΩ
3) If the resistance value is normal in step 2, check and repair the short of tilt horizontal harness.
Komatsu error codes list – Error codes description and troubleshooting tips for Komatsu construction eqiupment