Automatic Transmission: Maintenance Ford Focus II

Transmission Fluid Temperature (TFT) Sensor

The transmission fluid temperature (TFT) sensor is located on the internal wiring harness to the solenoid valves in the fluid pan.

It is a resistor and measures the transmission fluid temperature.

The transmission fluid temperature is used by the PCM for the following functions

1. Applying the torque converter clutch is not permitted until the transmission fluid reaches a certain temperature.
2. Engagement of 4th gear is prevented in extreme sub-zero temperatures until the normal operating temperature is reached.
3. If the transmission fluid temperature is excessive, a pre-set fixed shift curve is selected and the torque converter lock-up clutch is closed in 2, 3 and 4, and the transmission warning indicator is activated. No substitute signal is available for the TFT sensor.

Scheme 143

The O/D switch transmits a signal to the PCM to select or suppress 4th gear in manual selector lever position D.

The signal of the O/D switch is used for the following functions

1. as an input signal to convey the driver's intent to the PCM.
2. to display the driver's intent with the O/D indicator in the instrument cluster.

No substitute signal is available for the O/D switch. If it should fail, it is always possible to shift into 4th gear in manual selector lever position D.

Scheme 144

When the ignition is switched on, the manual selector lever shift lock solenoid is actuated by depressing the brake (signal from the stoplamp switch). This retracts the locking pin so that the manual selector lever can be moved out of position P.

Scheme 145

Note. If P is selected again, the manual selector lever is locked again.

If the brake signal should fail due to a malfunction, manual unlocking is possible.

For this, the cover of the release mechanism must be removed and a suitable object (ignition key) pressed into the opening until the manual selector lever can be moved out of position P.

Check Fluid Level

Under normal conditions, there is no requirement to check the transaxle fluid level. However, if the transaxle is not functioning correctly, the transaxle may slip, shift slowly or there may be some sign of fluid leakage, the fluid level should be checked.

Note. Automatic transmission fluid expands when warmed. To obtain an accurate fluid level check, drive the vehicle until normal operating temperature is reached, approximately 30 km (20 miles).

Note. If the vehicle has been operated for an extended period at high speeds, in city traffic, during hot weather or while pulling a trailer the vehicle should be turned OFF for approximately 30 minutes to allow the fluid to cool before checking.

Note. Incorrect fluid level may affect the transaxle operation and could result in transaxle damage. To correctly check and add fluid to the transaxle, refer to PRELIMINARY INSPECTION in this article.

Scheme 146

1. Drive the vehicle 30 km (20 miles) or until the vehicle reaches normal operating temperature.
2. Park the vehicle on a level surface and engage the parking brake.
3. With your foot on the brake, start the engine and move the range selector lever through all the gear ranges. Allow sufficient time for each gear to engage.
4. Place the range selector in PARK and leave the engine running.
5. Remove the fluid level indicator and wipe it clean with a lint free cloth.
6. Install the fluid level indicator, making sure that it is fully seated in the filler tube.
7. Remove the fluid level indicator. The fluid should be within the designated areas.

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 transaxle damage. If an overfill reading is indicated, adjust fluid to correct level.

Low Fluid Level

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

Adding Fluid

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

Check The Fluid Condition

1. Check the fluid level. Refer to «PRELIMINARY INSPECTION»(ref-255393-S27282065952007053100000) in this article.
2. Observe the color and the odor. The color under normal circumstances should be reddish, not brown or black.
3. Allow the fluid to drip onto a facial tissue and examine the stain.
4. If evidence of solid material is found, the transaxle fluid pan should be removed for further inspection.
5. If fluid contamination or transaxle failure is confirmed by the sediment in the bottom of the transaxle fluid pan, the transaxle must be disassembled and completely cleaned.
6. Carry out diagnostic checks and adjustments. Refer to «DIAGNOSIS BY SYMPTOM»(ref-255393-S30097251742007053100000) in this article.

Transmission Fluid Cooler

Note. Cleaning and backflushing the transaxle fluid cooling system along with normal cleaning and inspection procedures as outlined in this article during disassembly and reassembly will keep contamination from reentering the transaxle and causing a repeat repair.

When internal wear or damage has occurred in the transaxle, metal particles, clutch plate material or band material may have been carried into the torque converter and transaxle fluid cooler. These contaminants are a major cause of recurring transaxle troubles and must be removed from the system before the transaxle is put back in use.

Other Concerns: Fluid Venting Or Foaming

OTHER CONCERNS: FLUID VENTING OR FOAMING

Transmission Fluid Drain and Refill

MATERIALS

Scheme 147

Scheme 148

Scheme 149

Scheme 150

Scheme 151

Scheme 152

1. With the vehicle in NEUTRAL, position it on a hoist. For additional information, refer to «JACKING AND LIFTING»(ref-255374) .
2. Disconnect the return hose from the transmission fluid cooler. Push the connector fitting into the cooler line. Press the yellow release button. Pull the connector fitting off the cooler line.
3. Attach a length of suitable drain hose to the transmission fluid cooler return tube.
4. Lower the vehicle.
5. Insert the drain hose into a calibrated 10 liter (10.5 quarts) container. CAUTION: To prevent damage to the transaxle, do not run the engine above idle. NOTE: If the fluid return rate is less than 0.95L (1.0 qt) in 30 seconds, or if the return hose pulsates, check for restrictions at the pump, cooler or cooler lines.
6. Run the engine at idle and pump out 3L (3.17 qt) of automatic transmission fluid.
7. Switch OFF the engine.
8. Remove the fluid level indicator from the fluid level indicator tube.
9. Add 3 liters of automatic transmission fluid to the transaxle. CAUTION: To prevent damage to the transaxle, do not run the engine above idle. NOTE: If the fluid return rate is less than 0.95 liters in 30 seconds, or if the return hose pulsates, check for restrictions at the pump, cooler or cooler lines.
10. Run the engine at idle and pump out 3L (3.17 qt) of automatic transmission fluid.
11. Switch OFF the engine.
12. Add 3L (3.17 qt) of automatic transmission fluid to the transaxle. CAUTION: To prevent damage to the transaxle, do not run the engine above idle.
13. Run the engine at idle and pump out 3L (3.17 qt) of automatic transmission fluid.
14. Switch OFF the engine.
15. Raise the vehicle.
16. Remove the length of suitable drain hose from the transmission fluid return hose.
17. Connect the return hose to the transmission fluid cooler.
18. Lower the vehicle.
19. Add 3L (3.17 qt) of automatic transmission fluid to the transaxle.
20. Install the fluid level indicator to the fluid level indicator tube. CAUTION: To prevent damage to the transaxle, do not run the engine above idle.
21. Run the engine.
22. Check the automatic transmission fluid level and fill if necessary.

Transmission Fluid Pan

MATERIALS

Scheme 153

Scheme 154

1. With the vehicle in NEUTRAL, position it on a hoist. For additional information, refer to «JACKING AND LIFTING»(ref-255374) . CAUTION: The transmission fluid pan is filled with automatic transmission fluid and can not be drained before removing.
2. Remove the transmission fluid pan. Remove the bolts. Using a suitable tool, separate the bead of sealer.
3. Clean the silicone from the transmission fluid pan and transaxle case surfaces thoroughly with metal surface cleaner.