Preliminary Inspection
Preliminary InspectionWARNING: If equipped with fire suppression system, refer to Fire Suppression System for Important Safety Warnings.
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 as to 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 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
^ Upshift
^ 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 vehicle has been operated for an extended period of time at highway speeds, in city traffic, in hot weather, or when 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 has 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 range selector lever in the PARK 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.
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 malfunction and/or damage. 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, malfunction and/or damage. This could also indicate a leak in one of the transmission seals or gaskets.
Adding Fluid
CAUTION: The use of any type of transmission fluid other than specified could result in transmission malfunction and/or damage.
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 General Specifications 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, coolers and cooler lines.
7. Carry out diagnostic checks and adjustments; refer to Diagnosis By Symptom. Diagnosis By Symptom
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.