Ford Mustang (1999-2004) Service Manual: Preliminary Inspection

The following items must be checked prior to beginning the diagnostic procedures:

Know and Understand the Concern

In order to correctly diagnose a concern, first understand the customer complaint or condition.

Customer contact may be required in order to begin to verify the concern. Understand the conditions, including when the concern occurs. For example:

  • Hot or cold vehicle temperature
  • Hot or cold ambient temperature
  • Vehicle driving conditions
  • Vehicle loaded/unloaded

After understanding when and how the concern occurs, proceed to Verification of Condition.

Verification of Condition

This section provides information that must be used in both determining the actual cause of customer concerns and carrying out the appropriate procedures.

The following procedures must be used when verifying customer concerns for the transmission.

Determine Customer Concern

NOTE: Some transmission conditions can cause engine concerns. An electronic pressure control short circuit can cause engine misfiring. The torque converter clutch not disengaging will stall the engine.

Determine customer concerns relative to vehicle use and dependent driving conditions, paying attention to the following items:

  • Hot or cold vehicle operating temperature
  • Hot or cold ambient temperatures
  • Type of terrain
  • Vehicle loaded/unloaded
  • City/highway driving
  • Upshifting
  • Downshift
  • Coasting
  • Engagement
  • Noise/vibration - check for dependencies, either rpm dependent, vehicle speed dependent, shift dependent, gear dependent, range dependent, or temperature dependent.

Check Fluid Level and Condition

Fluid Level Check

CAUTION: The vehicle should not be driven if the fluid level indicator shows the fluid below the DO NOT DRIVE mark or internal failure could result.

NOTE: If the vehicle has been operated for an extended period, at high highway speeds, in city traffic, during hot weather, or while pulling a trailer, the fluid needs to cool down to obtain an accurate reading.

NOTE: The fluid level reading on the indicator will differ from operating and ambient temperatures. The correct reading should be within the normal operating temperature range.

Under normal circumstances the fluid level should be checked during normal maintenance. If the transmission starts to slip, shifts slowly, or shows signs of fluid leaking, the fluid level should be checked.

1. With the transmission in P (PARK), the engine at idle, foot pressed on the brake, move the range selector lever through each gear and allow engagement of each gear. Place the transmission range selector lever in the P position.

2. Wipe the fluid level indicator cap and remove the indicator.

3. Wipe the indicator with a clean cloth.

4. Install the indicator back in the filler tube until it is fully seated, then remove the indicator. The fluid level should be within the normal operating temperature range.

Fluid Level Check


Fluid Level Check

High Fluid Level

A fluid level that is too high may cause the fluid to become aerated due to the churning action of the rotating internal parts. This will cause erratic control pressure, foaming, loss of fluid from the vent tube, and possible transmission failure. If an overfill reading is indicated, drain and refill the transmission.

Low Fluid Level

A low fluid level could result in poor transmission engagement, slipping, or failure. This could also indicate a leak in one of the transmission seals or gaskets.

Adding Fluid

CAUTION: The use of any other type of transmission fluid than specified could result in transmission failure.

If fluid needs to be added, add fluid in 0.25L (1/2 pint) increments through the filler tube. Do not overfill the fluid. For fluid type, refer to the specification chart.

Fluid Condition Check

1. Check the fluid level.

2. Observe the color and the odor. The color under normal circumstances should be dark reddish, not brown or black or have a burnt odor.

3. Hold the fluid level indicator over a white facial tissue and allow the fluid to drip onto the facial tissue and examine the stain.

4. If evidence of solid material is found, the transmission fluid pan should be removed for further inspection.

5. If the stain is a foamy pink color this may indicate coolant in the transmission. The engine cooling system should also be inspected at this time.

6. If fluid contamination or transmission failure is confirmed by the sediment in the bottom of the fluid pan, the transmission must be disassembled and completely cleaned. This includes the torque converter and cooler tubes. The oil-to-air cooler will need to be installed.

7. Carry out diagnostic checks and adjustments. Refer to Diagnosis By Symptom in this section.

Road Testing Vehicle

NOTE: Always drive the vehicle in a safe manner according to the driving conditions and obey all traffic laws.

The shift point road test and torque converter operation tests provide diagnostic information on transmission shift controls and torque converter operation.

    Diagnostic Strategy
    Troubleshooting an electronically controlled automatic transmission is simplified by using the proven method of diagnosis. One of the most important things to remember is that there is a defin ...

    Shift Point Road Test
    This test verifies that the shift control system is operating correctly. 1. Bring engine and transmission up to normal operating temperature. 2. Operate vehicle with transmission range selecto ...

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