Ford Fusion: Automatic Transmission - 6-Speed Automatic Transmission – 6F35 / Transmission Stall Speed Test. Diagnosis and Testing
Stall Speed Test
WARNING:
Block all wheels, set the parking brake and firmly apply the
service brake to reduce the risk of vehicle movement during this
procedure. Failure to follow these instructions may result in serious
personal injury.
NOTE:
Carry out the Line Pressure Test prior to the Stall Speed
Test. If line pressure is low, do not carry out the stall test or
additional transmission damage will occur. Do not maintain Wide Open
Throttle (WOT) in any gear range for more than 5 seconds.
NOTE:
If the engine speed exceeds maximum specified rpm, release the accelerator pedal immediately.
NOTE:
Only perform the stall speed test with the engine and transmission at normal operating temperatures.
To
prevent damage to transmission and driveline components, the PCM will
truncate engine torque output when a stall condition exists. Because of
this torque truncation, the stall test cannot be used as a diagnostic
test for determining the health of the transmission clutches.
The PCM monitors clutch performance and will set one or more DTCs when an undesired slip is detected.
The
torque converter stator one-way clutch should hold at idle and during
acceleration. A failed one-way clutch can be identified if all of the following conditions/symptoms exist:
-
Transmission fluid is clean and free of excessive contamination
-
Normal/expected vehicle performance at cruising speed
-
Poor engine idle quality. The engine may even stall
-
Very poor acceleration/Lack of power
-
Very low stall RPM: <1500 RPM. Perform test procedure below:
-
Apply the parking brake.
-
Connect the scan tool. Navigate to Datalogger: PCM
-
Monitor the PIDs: APP (%), RPM, LOAD (%) and GEAR_CMD
-
Start the engine.
-
Place the transmission in reverse.
-
Start datalogger recording.
-
With the brake pedal firmly applied, press the accelerator pedal to 100% for 2-3 seconds until engine RPM stabilizes. Release the accelerator pedal.
-
Place the transmission in neutral.
-
Press the accelerator pedal to maintain 1500 RPM for 10 seconds to allow the torque converter to cool. Release the accelerator pedal.
-
Place the transmission in drive.
-
With the brake pedal firmly applied, press the accelerator pedal to 100% for 2-3 seconds until engine RPM stabilizes. Release the accelerator pedal.
-
Place the transmission in neutral.
-
Press the accelerator pedal to maintain 1500 RPM for 10 seconds to allow the torque converter to cool. Release the accelerator pedal.
-
Turn the engine off.
-
Review the recording. A properly functioning stator one-way clutch should fall within the following parameters:
-
GEAR_CMD = Reverse or 1st Gear commanded
Line Pressure Test
NOTE:
Perform the line pressure test prior to performing the stall
speed test. If the line pressure is low at stall, do not perform the
stall speed test or transmission damage will occur...
Symptom Chart
Forward Clutch
For forward (1,2,3,4) clutch operation, REFER to: Transmission Description - System Operation and Component Description (307-01A Automatic Transmission - 6-Speed Automatic Transmission – 6F35, Description and Operation)...
Other information:
Removal
NOTE:
Left hand (LH) side shown, right hand (RH) side similar.
NOTE:
Engine removed for clarity.
Overview
Remove the hood and prop rod.
Refer to: Hood (501-02 Front End Body Panels, Removal and Installation)...
Removal
WARNING:
Front seat backrest trim covers installed on seats equipped
with seat side airbags cannot be repaired. A new trim cover must be
installed. Cleaning is permissible. Failure to follow these instructions
may result in the seat side airbag deploying incorrectly and increase
the risk of serious personal injury or death in a crash...