Diagnosis and Testing — Accessory Drive

Inspection and Verification

1. 1
   Verify the customer concern.
2. 2
   Visually inspect for obvious signs of mechanical damage.

Visual Inspection Chart

• Damaged or contaminated accessory drive belt
• Damaged or contaminated pulley(s)
• Incorrect accessory drive belt
• Incorrect accessory drive belt installation
• Generator
• A/C compressor
• Pulley(s)
• Accessory

3. If an obvious cause for an observed or reported concern is found, correct the cause (if possible) before proceeding to the next step.

Accessory drive belt concerns

NOTICE: Do not lubricate the accessory drive belt, as damage to the accessory drive belt material may occur.

Cracking

Accessory drive belts are made of rubber, which hardens over time and may develop cracks. Because the accessory drive belt runs over the back of some pulleys, the grooves are exposed. Small cracks are not considered an accessory drive belt fault. Only if a crack is deep enough to reach the bottom of a groove to expose the cord, or if any pieces are missing from the accessory drive belt, is the accessory drive belt condition considered unacceptable.

1. Check the accessory drive belt for cracks. If the damage exceeds the acceptable limit, install a new accessory drive belt.
   REFER TO: Accessory Drive Belt (303-05B Accessory Drive — 2 L EcoBoost (177 kW/240 L PS) — MI4, Removal and Installation).

Chunking

Chunking describes a condition where long sections of rubber separate from the ribs of the accessory drive belt. This is considered a failure of the accessory drive belt.

2. Check the accessory drive belt for damage. If any pieces are missing, install a new accessory drive belt.
   REFER TO: Accessory Drive Belt (303-05B Accessory Drive — 2 L EcoBoost (177 kW/240 L PS) — MI4, Removal and Installation).

Peeling

Peeling is dust that forms between the ribs of the accessory drive belt from rubber that wears off the belt when it is new. There may also be loose particles left on the accessory drive belt during the manufacturing process. These wear off and form small rubber balls that then become lodged in the grooves of the accessory drive belt. This condition usually goes away after 4800–8000 km (3000–5000 miles) of normal driving.

3. Check the accessory drive belt for pilling. The condition of the accessory drive belt should be compared to the illustration.
   
   1. Small scattered pellets. Not considered a concern. No action required.
   2. Small scattered pellets. Not considered a concern. No action required.
   3. Longer pellets up to 50% of rib height. Possible noise concern. INSTALL a new accessory drive belt if noise is heard.
      REFER TO: Accessory Drive Belt (303-05B Accessory Drive – 2 L EcoBoost (177 kW/240 L PS) – MI4, Removal and Installation).
   4. Longer pellets up to 50% of rib height. Possible noise concern. INSTALL a new accessory drive belt if noise is heard.
      REFER TO: Accessory Drive Belt (303-05B Accessory Drive – 2 L EcoBoost (177 kW/240 L PS) – MI4, Removal and Installation).
   5. Heavy deposits in the grooves. Possible noise and stability concerns. INSTALL a new accessory drive belt.
      REFER TO: Accessory Drive Belt (303-05B Accessory Drive – 2 L EcoBoost (177 kW/240 L PS) – MI4, Removal and Installation).
   6. Heavy deposits in the grooves. Possible noise and stability concerns. INSTALL a new accessory drive belt.
      REFER TO: Accessory Drive Belt (303-05B Accessory Drive – 2 L EcoBoost (177 kW/240 L PS) – MI4, Removal and Installation).

Incorrect Installation

Accessory drive belt noise may be caused by the accessory drive belt being incorrectly installed on the pulley, as shown in the following illustration. Make sure that all the V-grooves on the accessory drive belt contact the pulley correctly.

4. If the cause is not visually apparent, verify the symptom and refer to the Symptom Chart.

Global Customer Symptom Codes (GCSC) Table

The diagnosis in this manual assumes a certain level of skill and knowledge of Ford-approved diagnostic procedures.
REFER TO: Diagnostic Methods (100-00 General Information, Description and Operation).

Symptom Chart

Symptom Chart: Accessory Drive

The diagnosis in this manual assumes a certain level of skill and knowledge of Ford-approved diagnostic procedures.
REFER TO: Diagnostic Methods (100-00 General Information, Description and Operation).

Symptom Chart

Pinpoint Tests

NOTICE: Do not lubricate the accessory drive belt, as damage to the accessory drive belt material may occur.

Component Tests

Accessory Drive Belt Tensioner - Static Check

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

1. 1
   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 inside may be damaged. INSTALL a new accessory drive belt tensioner as necessary.
   REFER TO: Accessory Drive Belt Tensioner (303-05A Accessory Drive - 1.5 L EcoBoost (132 kW/180 L PS) - I3 (Y1), Removal and Installation).
2. 2
   Disconnect the accessory drive belt in the area of the accessory drive belt tensioner.
3. 3
   Using a suitable tool, move the accessory drive belt tensioner from the relaxed position through its full travel and back to the relaxed position to make sure there is no excessive stick, binding or catching, and make sure the accessory drive belt tensioner spring is tensioned.
4. 4
   Rotate the accessory drive belt tensioner pulley and check for damage, freedom of rotation and alignment. INSTALL a new accessory drive belt tensioner as necessary.
   REFER TO: Accessory Drive Belt Tensioner (303-05A Accessory Drive - 1.5 L EcoBoost (132 kW/180 L PS) - I3 (Y1), Removal and Installation).
5. 5
   If the accessory drive belt tensioner meets the criteria above, proceed to the dynamic check of the accessory drive belt tensioner. If the accessory drive belt tensioner does not meet the criteria above, INSTALL a new accessory drive belt tensioner.
   REFER TO: Accessory Drive Belt Tensioner (303-05A Accessory Drive - 1.5 L EcoBoost (132 kW/180 L PS) - I3 (Y1), Removal and Installation).

Accessory Drive Belt Tensioner - Dynamic Check

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

1. 1
   With the engine running, observe the movement of the accessory drive belt tensioner. The accessory drive belt tensioner should move (respond) when the engine is quickly accelerated or when the air conditioning clutch cycles on and off (movement may be up to 4 mm). If the accessory drive belt tensioner movement is erratic without engine acceleration or air conditioning clutch cycling, the pulley or shaft may be bent or out of round, or the damping mechanism inside the accessory drive belt tensioner may be damaged. INSTALL a new accessory drive belt tensioner as necessary.
   REFER TO: Accessory Drive Belt Tensioner (303-05A Accessory Drive - 1.5 L EcoBoost (132 kW/180 L PS) - I3 (Y1), Removal and Installation).
2. 2
   Excessive wear of the accessory drive belt (uneven groove depth on the accessory drive belt) may cause excessive movement of the belt tensioner. Check the condition by installing a new accessory drive belt.
   Refer to: Accessory Drive Belt (303-05B Accessory Drive – 2 L EcoBoost (177 kW/240 L hp) – MI4, Removal and Installation).