Diagnostics and checks of accessory drive

Inspection and verification

1. Check the validity of the customer's complaint.

2. Visually inspect for obvious signs of mechanical damage.

Visual inspection table

Mechanical factors:

• Damaged or dirty accessory drive belt
• Incorrect accessory drive belt
• Accessory drive belt tensioner.
• Idle pulley of accessory drive belt.
• Generator
• Power steering pump
• Air Conditioning (A/C) Compressor
• Pulley(s)
• Loosening of fasteners

3. If an obvious cause for the problem you identified or the customer described is found, correct it (if possible) before moving on to further actions.

CAUTION: Do not lubricate the accessory drive belt, accessory drive belt tensioner, or idler pulley(s), as this may cause damage to the material structure of the accessory drive belt, accessory drive belt tensioner damper mechanism, accessory drive belt tensioner pulley bearing, and idler pulley(s) bearing.

NOTE: Up to 15 cracks per belt rib at a distance of 100 mm are allowed. If cracks exceed the allowable limit or any belt fragments are found missing, install a new accessory drive belt.

4. The condition of the accessory drive belt should be compared with the figure and appropriate action should be taken.

• 1. Small scattered deposits of rubber crumb are not a problem and therefore a new accessory drive belt should not be installed.
• 2. Extended rubber crumb deposits, occupying up to 50% of the accessory drive belt rib height - this is not a problem, but it may be the cause of increased noise. If increased noise is present, install a new accessory drive belt. Vehicles with 1.6L Zetec-SE/1.4L engine For more information, refer to Accessory Drive Belt - available in this section. Vehicles with 1.6L Duratec engine. For more information, refer to Accessory Drive Belt - 1.6L Duratec available in this section. Vehicles with 1.8L/2.0L/1.6L Zetec-E engine. For more information, refer to Accessory Drive Belt - available in this section. Vehicles without accessory drive belt tensioner. For more information, refer to Accessory Drive Belt - Vehicles without accessory drive belt tensioner available in this section.
• 3. Large deposits of crumb rubber along the grooves are a problem and may cause increased noise and instability of the accessory drive belt. If large deposits or excessive accessory drive belt noise are evident, install a new accessory drive belt. Vehicles with 1.6L Zetec-SE/1.4L engine For more information, refer to Accessory Drive Belt - available in this section. Vehicles with 1.6L Duratec engine For more information, refer to Accessory Drive Belt - 1.6L Duratec available in this section. Vehicles with 1.8L/2.0L/1.6L Zetec-E engine For more information, refer to Accessory Drive Belt - available in this section. Vehicles without accessory drive belt tensioner For more information, refer to Accessory Drive Belt - Vehicles without accessory drive belt tensioner available in this section.

5. Check the accessory drive belt for cracks. If the damage exceeds the permissible limit, install a new accessory drive belt. Vehicles with 1.6L Zetec-SE/1.4L engine For more information, refer to Accessory Drive Belt - available in this section. Vehicles with 1.6L Duratec engine For more information, refer to Accessory Drive Belt - 1.6L Duratec available in this section. Vehicles with 1.8L/2.0L/1.6L Zetec-E engine For more information, refer to Accessory Drive Belt - available in this section. Vehicles without accessory drive belt tensioner For more information, refer to Accessory Drive Belt - Vehicles without accessory drive belt tensioner available in this section.




6. Check the accessory drive belt for damage. If there are no large pieces of belt, install a new accessory drive belt. Vehicles with 1.6L Zetec-SE/1.4L engine For more information, refer to Accessory Drive Belt - available in this section. Vehicles with 1.6L Duratec engine For more information, refer to Accessory Drive Belt - 1.6L Duratec available in this section. Vehicles with 1.8L/2.0L/1.6L Zetec-E engine For more information, refer to Accessory Drive Belt - available in this section. Vehicles without accessory drive belt tensioner For more information, refer to Accessory Drive Belt - Vehicles without accessory drive belt tensioner available in this section.

7. Inspect the accessory drive belt for fraying. Compare the accessory drive belt condition to the illustrations. For levels 1 through 3, the accessory drive belt does NOT require replacement. For levels 4 and 5, INSTALL a new accessory drive belt. Vehicles with 1.6L Zetec-SE/1.4L engine Refer to Accessory Drive Belt - available in this section for more information. Vehicles with 1.6L Duratec engine Refer to Accessory Drive Belt - 1.6L Duratec available in this section for more information. Vehicles with 1.8L/2.0L/1.6L Zetec-E engine Refer to Accessory Drive Belt - available in this section for more information. Vehicles without accessory drive belt tensioner Refer to Accessory Drive Belt - Vehicles without accessory drive belt tensioner available in this section for more information.

• 1. No wear (new belt)
• 2. Wear and tear is just beginning
• 3. Light wear
• 4. High wear rate without cord destruction
• 5. High degree of wear with cord destruction

8. If the cause is not visually obvious, check the malfunction symptom and refer to the Malfunction Symptom Table.

Table of signs of malfunction

State	Possible Causes	Action
•Noise or squealing from accessory drive belt	•Wear or damage to accessory drive elements.	•CHECK the system with the engine running and the accessory drive belt removed (run the engine for a very short period only). If noise is present, the accessory drive system is not the cause. If there is no noise, the accessory drive system is the cause. CHECK where the noise is coming from and INSTALL new parts if necessary. CHECK that the system is operating correctly.
	•Incorrect installation of accessory drive elements.	•CHECK accessory drive components for proper installation. REPAIR if necessary.
	•Accessory drive belt is not installed correctly.	•CHECK that the accessory drive belt is correctly installed in the pulley grooves. If necessary, INSTALL a new accessory drive belt. Vehicles with 1.6L Zetec-SE/1.4L engine Refer to Accessory Drive Belt - available in this section for additional information. Vehicles with 1.6L Duratec engine Refer to Accessory Drive Belt - 1.6L Duratec available in this section for additional information. Vehicles with 1.8L/2.0L/1.6L Zetec-E engine Refer to Accessory Drive Belt - available in this section for additional information. Vehicles without accessory drive belt tensioner Refer to Accessory Drive Belt - Vehicles without accessory drive belt tensioner available in this section for additional information. CHECK that the system is operating correctly.
	•Pulley(s)	•CHECK pulley(s) for damage, freedom of rotation and proper alignment. INSTALL new ones if necessary.
	•Grease or other contamination.	•CHECK the accessory drive belt for dirt or damage. REMOVE the accessory drive belt and wash it using detergent and water. If the accessory drive belt does not clean or is damaged, INSTALL a new accessory drive belt. Vehicles with 1.6L Zetec-SE/1.4L engine Refer to Accessory Drive Belt - available in this section for additional information. Vehicles with 1.6L Duratec engine Refer to Accessory Drive Belt - 1.6L Duratec available in this section for additional information. Vehicles with 1.8L/2.0L/1.6L Zetec-E engine Refer to Accessory Drive Belt - available in this section for additional information. Vehicles without accessory drive belt tensioner Refer to Accessory Drive Belt - Vehicles without accessory drive belt tensioner available in this section for additional information. CHECK the system operates correctly.
	•Accessory drive belt	• CHECK that the accessory drive belt is applied correctly. INSTALL a new accessory drive belt. CHECK that the system operates correctly. Vehicles with 1.6L Zetec-SE/1.4L engine Refer to Accessory Drive Belt - in this section for additional information. Vehicles with 1.6L Duratec engine Refer to Accessory Drive Belt - 1.6L Duratec in this section for additional information. Vehicles with 1.8L/2.0L/1.6L Zetec-E engine Refer to Accessory Drive Belt - in this section for additional information. Vehicles without accessory drive belt tensioner Refer to Accessory Drive Belt - Vehicles without accessory drive belt tensioner in this section for additional information. CHECK that the system operates correctly.
•Fraying of accessory drive belt	•Accessory drive belt. •Pulley(s) •Generator. •Power steering pump •A/C compressor.	•CHECK pulley(s) for damage, freedom of rotation and proper alignment. Install new components if necessary. CHECK system for proper operation.
•Accessory drive belt does not hold tension	•The accessory drive belt is cracked or damaged.	•INSPECT the accessory drive belt for cracks or damage. If the cracks are within the acceptable limit, the accessory drive belt is OK. If the cracks are greater than the acceptable limit, INSTALL a new accessory drive belt. Vehicles with 1.6L Zetec-SE/1.4L engine Refer to Accessory Drive Belt - available in this section for additional information. Vehicles with 1.6L Duratec engine Refer to Accessory Drive Belt - 1.6L Duratec available in this section for additional information. Vehicles with 1.8L/2.0L/1.6L Zetec-E engine Refer to Accessory Drive Belt - available in this section for additional information. Vehicles without accessory drive belt tensioner Refer to Accessory Drive Belt - Vehicles without accessory drive belt tensioner available in this section for additional information. CHECK that the system is operating correctly.
	•Worn or damaged accessory drive belt tensioner.	•CHECK the accessory drive belt tensioner for proper operation or damage. If necessary, INSTALL a new accessory drive belt tensioner. Vehicles with 1.6L Zetec-SE/1.4L engine Refer to Accessory Drive Belt Tensioner - available in this section for additional information. Vehicles with 1.6L Duratec engine Refer to Accessory Drive Belt Tensioner - 1.6L Duratec available in this section for additional information. Vehicles with 1.8L/2.0L/1.6L Zetec-E engine Refer to Accessory Drive Belt Tensioner - available in this section for additional information. CHECK the system for proper operation.

Element checks

Accessory Drive Belt Tensioner - Static Check

The accessory drive belt tensioner can be checked statically as follows:

1. Disconnect the accessory drive belt at the accessory drive belt tensioner area.

2. Using the correct tool, move the accessory drive belt tensioner from its free position through its full piston stroke and back to the free position to ensure that there is no binding or seizing, and ensure that the accessory drive belt tensioner spring is under tension.

3. Rotate the accessory drive belt tensioner pulley and check for damage, freedom of rotation and proper alignment. INSTALL a new accessory drive belt tensioner if necessary.

4. Inspect the area around the accessory drive belt tensioner for grease or other contamination. Repair any leaks before installing a new accessory drive belt tensioner. If the accessory drive belt tensioner is contaminated, do not attempt to clean it as the damping mechanism located inside may be damaged. INSTALL a new accessory drive belt tensioner if necessary.

5. If the accessory drive belt tensioner meets the above criteria, proceed to the accessory drive belt tensioner dynamic inspection. If the accessory drive belt tensioner does not meet the above criteria, INSTALL a new accessory drive belt tensioner.

Accessory Drive Belt Tensioner - Dynamic Test

The accessory drive belt tensioner can be checked dynamically by proceeding as follows:

1. With the engine running, observe the accessory drive belt tensioner movement. The accessory drive belt tensioner should move (respond) when the engine is accelerated rapidly or when the A/C clutch is cycled. If the accessory drive belt tensioner movement is not consistent without engine acceleration or A/C clutch cycling, the pulley or shaft may be warped or out of round, or the damping mechanism located inside the accessory drive belt tensioner may be damaged. Excessive accessory drive belt play (uneven groove depth in the accessory drive belt) may be the cause of excessive accessory drive belt tensioner movement. Check for the problem condition by installing a new accessory drive belt. Vehicles with 1.6L Zetec-SE/1.4L engine Refer to Accessory Drive Belt Tensioner - located in this section for additional information. Vehicles with 1.6L Duratec engine For additional information, refer to Accessory Drive Belt Tensioner - 1.6L Duratec in this section. Vehicles with 1.8L/2.0L/1.6L Zetec-E engine. For additional information, refer to Accessory Drive Belt Tensioner - in this section. CHECK for proper system operation.