AUTO-TENSIONER CHECK

OPERATION CHECK

Turn OFF the engine from the idle state then check to see that the drive belt is not protruding from the pulley width of the auto-tensioner.

Remove the drive belt.(Refer to ).

Securely insert the spindle handle or ratchet handle with a 12.7 mm insertion angle into the jig hole of the auto tensioner. Turn the auto-tensioner to the left and right to check and see that there is no threading.

If there are any problems in the procedure 1 or 3, replace the auto-tensioner.(Refer to ).

Install the drive belt.(Refer to ).

FUNCTION CHECK

You can verify if the auto-tensioner is defective or not by checking the drive belt tension.

When using MUT-II

Check the drive belt tension. (Refer to ).

Measure the drive belt tension vibration frequency by the following procedures:

CAUTION

To prevent damage to MUT-II, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting MUT-II.

Connect special tool belt tension meter set (MB991668) to the MUT-II.

Connect the MUT-II to the diagnosis connector.

Turn the ignition switch to ON position, and select "BELT TENSION" on the menu screen.

CAUTION

The temperature of the surface of the belt should be as close to normal temperature as possible.

Do not allow any contaminants such as water or oil to get onto the microphone.

If strong gusts of wind blow against the microphone or if there are any loud sources of noise nearby, the values measured by the microphone may not correspond to actual values.

If the microphone is touching the belt while the measurement is being made, the values measured by the microphone may not correspond to actual values.

Do not take the measurement while the vehicle's engine is running.

Hold special tool belt tension meter set (MB991668) to the middle of the drive belt between the pulleys (at the place indicated by arrow), approximately 10 - 20 mm away from the rear surface of the belt so that it is perpendicular to the belt (within an angle of ± 15 degree).

Gently tap the middle of the belt between the pulleys (the place indicated by the arrow) with your finger as shown in the illustration, and measure that the vibration frequency of the belt is within the standard value.

Standard value: 110 - 144 Hz

If not within the standard value, replace the auto-tensioner. (Refer to ).

When using V.C.I.

Check the drive belt tension. (Refer to ).

Measure the drive belt tension vibration frequency by the following procedures:

CAUTION

To prevent damage to special tool V.C.I. (MB991824), always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting special tool V.C.I. (MB991824).

Connect special tool belt tension meter set (MB991668) to special tool V.C.I. (MB991824).

Connect special tool MUT-III main harness B (MB991911) to special tool V.C.I. (MB991824).

Connect special tool MUT-III main harness B (MB991911) to the diagnosis connector.

Turn the ignition switch to "ON" position, and select "Belt Tension" on the menu screen.

CAUTION

The temperature of the surface of the belt should be as close to normal temperature as possible.

Do not allow any contaminants such as water or oil to get onto the microphone.

If strong gusts of wind blow against the microphone or if there are any loud sources of noise nearby, the values measured by the microphone may not correspond to actual values.

If the microphone is touching the belt while the measurement is being made, the values measured by the microphone may not correspond to actual values.

Do not take the measurement while the vehicle's engine is running.

Hold special tool belt tension meter set (MB991668) to the middle of the drive belt between the pulleys (at the place indicated by arrow), approximately 10 - 20 mm away from the rear surface of the belt so that it is perpendicular to the belt (within an angle of ± 15 degree).

Gently tap the middle of the belt between the pulleys (the place indicated by the arrow) with your finger as shown in the illustration, and measure that the vibration frequency of the belt is within the standard value.

Standard value: 110 - 144 Hz

If not within the standard value, replace the alternator drive belt auto tensioner. (Refer to ).

When using a tension gauge

Check the drive belt tension. (Refer to ).

Use a belt tension gauge in the middle of the belt between the pulleys (at the place indicated by the arrow) to measure that the belt tension is within the standard value.

Standard value: 245 - 412 N

If not within the standard value, replace the auto-tensioner.(Refer to ).


	AUTO-TENSIONER CHECK
	OPERATION CHECK Turn OFF the engine from the idle state then check to see that the drive belt is not protruding from the pulley width of the auto-tensioner. Remove the drive belt.(Refer to ).
	Securely insert the spindle handle or ratchet handle with a 12.7 mm insertion angle into the jig hole of the auto tensioner. Turn the auto-tensioner to the left and right to check and see that there is no threading. If there are any problems in the procedure 1 or 3, replace the auto-tensioner.(Refer to ). Install the drive belt.(Refer to ).
	FUNCTION CHECK You can verify if the auto-tensioner is defective or not by checking the drive belt tension.
	When using MUT-II Check the drive belt tension. (Refer to ). Measure the drive belt tension vibration frequency by the following procedures:
	CAUTION To prevent damage to MUT-II, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting MUT-II. Connect special tool belt tension meter set (MB991668) to the MUT-II. Connect the MUT-II to the diagnosis connector. Turn the ignition switch to ON position, and select "BELT TENSION" on the menu screen. CAUTION The temperature of the surface of the belt should be as close to normal temperature as possible. Do not allow any contaminants such as water or oil to get onto the microphone. If strong gusts of wind blow against the microphone or if there are any loud sources of noise nearby, the values measured by the microphone may not correspond to actual values. If the microphone is touching the belt while the measurement is being made, the values measured by the microphone may not correspond to actual values. Do not take the measurement while the vehicle's engine is running.
	Hold special tool belt tension meter set (MB991668) to the middle of the drive belt between the pulleys (at the place indicated by arrow), approximately 10 - 20 mm away from the rear surface of the belt so that it is perpendicular to the belt (within an angle of ± 15 degree). Gently tap the middle of the belt between the pulleys (the place indicated by the arrow) with your finger as shown in the illustration, and measure that the vibration frequency of the belt is within the standard value. Standard value: 110 - 144 Hz If not within the standard value, replace the auto-tensioner. (Refer to ).
	When using V.C.I. Check the drive belt tension. (Refer to ). Measure the drive belt tension vibration frequency by the following procedures:
	CAUTION To prevent damage to special tool V.C.I. (MB991824), always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting special tool V.C.I. (MB991824). Connect special tool belt tension meter set (MB991668) to special tool V.C.I. (MB991824). Connect special tool MUT-III main harness B (MB991911) to special tool V.C.I. (MB991824). Connect special tool MUT-III main harness B (MB991911) to the diagnosis connector. Turn the ignition switch to "ON" position, and select "Belt Tension" on the menu screen. CAUTION The temperature of the surface of the belt should be as close to normal temperature as possible. Do not allow any contaminants such as water or oil to get onto the microphone. If strong gusts of wind blow against the microphone or if there are any loud sources of noise nearby, the values measured by the microphone may not correspond to actual values. If the microphone is touching the belt while the measurement is being made, the values measured by the microphone may not correspond to actual values. Do not take the measurement while the vehicle's engine is running.
	Hold special tool belt tension meter set (MB991668) to the middle of the drive belt between the pulleys (at the place indicated by arrow), approximately 10 - 20 mm away from the rear surface of the belt so that it is perpendicular to the belt (within an angle of ± 15 degree). Gently tap the middle of the belt between the pulleys (the place indicated by the arrow) with your finger as shown in the illustration, and measure that the vibration frequency of the belt is within the standard value. Standard value: 110 - 144 Hz If not within the standard value, replace the alternator drive belt auto tensioner. (Refer to ).
	When using a tension gauge Check the drive belt tension. (Refer to ).
	Use a belt tension gauge in the middle of the belt between the pulleys (at the place indicated by the arrow) to measure that the belt tension is within the standard value. Standard value: 245 - 412 N If not within the standard value, replace the auto-tensioner.(Refer to ).