Automatic Transmission - af40-6 Buick Regal V

Transmission Fluid Temperature Sensor Specifications

Transmission Fluid Temperature Sensor Specifications

Fastener Tightening Specifications

Fastener Tightening Specifications

Adhesives, Fluids, Lubricants, and Sealers

Adhesives, Fluids, Lubricants, and Sealers

Transmission General Specifications

Transmission General Specifications

Scheme 30

Scheme 31

Scheme 32

Symptoms - Automatic Transmission

Note. Use the symptom tables only if the following conditions are met: There are no DTCs set. The control modules can communicate via the serial data link. Review the system operation in order to familiarize yourself with the system functions. Refer to Transmission General Description , and Transmission Component and System Description .

Visual/Physical Inspection

Inspect the easily accessible or visible system components for obvious damage or conditions which could cause the symptom.

Intermittent

Faulty electrical connections or wiring may be the cause of intermittent conditions. Refer to Testing for Intermittent Conditions and Poor Connections .

Symptom List

Refer to a symptom diagnostic procedure from the following list in order to diagnose the symptom

1. Fluid Diagnosis «Transmission Fluid Level and Condition Check»(/buick/regal/v-2009-2013/remont/automatic-trans/#automatic-transmission-af40-6__transmission-fluid-level-and-condition-check) «Automatic Transmission Fluid Leaks»(/buick/regal/v-2009-2013/remont/automatic-trans/#automatic-transmission-af40-6__automatic-transmission-fluid-leaks) «Fluid Leak Diagnosis»(/buick/regal/v-2009-2013/remont/automatic-trans/#automatic-transmission-af40-6) .
2. Noise and Vibration Diagnosis «Noise and Vibration Analysis»(/buick/regal/v-2009-2013/remont/automatic-trans/#automatic-transmission-af40-6__noise-and-vibration-analysis) .
3. Symptom Not Found or No Symptom Detected «Transmission Fluid Level and Condition Check»(/buick/regal/v-2009-2013/remont/automatic-trans/#automatic-transmission-af40-6__transmission-fluid-level-and-condition-check) «Road Test»(/buick/regal/v-2009-2013/remont/automatic-trans/#automatic-transmission-af40-6__road-test) .

Scheme 33

The torque converter stator roller clutch can have two different malfunctions.

1. Inspect the control solenoid valve connectors and pins (2), oil temperature sensor connector and pins (1), input speed sensor connector and pins (3), output speed sensor connector and pins (4) for the following conditions: Damage Bent pins Debris Broken retaining tab Contamination
2. Ensure no metallic debris is inside the connectors near the terminal pins.
3. Inspect the control solenoid valve assembly leads for contamination or metallic debris.
4. Inspect for oil leakage from any of the gaskets.

Scheme 34

The torque converter stator roller clutch can have two different malfunctions.

1. Inspect the control solenoid (w/body and TCM) valve assembly connectors and pins (A, B, C) for the following conditions: Damage Bent pins Debris Broken retaining tab Contamination
2. Ensure no metallic debris is inside the connectors near the terminal pins.
3. Inspect the control solenoid (w/body and TCM) valve assembly solenoid leads for contamination or metallic debris.
4. Inspect for oil leakage from any of the gaskets.

Transmission Fluid Level and Condition Check

Note. The following operation includes 2 procedures: Drain and prefill transmission oil with the engine off after repair work on the transmission, removal and installation/exchange of transmission or axle shafts. After prefilling with the engine off, the transmission oil level must be checked with the engine running. Check transmission fluid level and correct with engine running.

Drain and Prefill

1. Remove the transmission fluid filler plug (1).
2. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#general-information__lifting-and-jacking-the-vehicle) .
3. Place basin underneath the vehicle.
4. Clean away all dirt and debris from the transmission fluid filler overflow tube area.
5. Remove the transmission fluid check bolt (5) from the transmission fluid filler tube (3) and DISCARD the O-Ring (4).
6. Remove the transmission fluid filler overflow tube from the transmission and DISCARD the seal (2).
7. Let the transmission fluid run out for 10 minutes.
8. Install and tighten the transmission fluid filler overflow tube to 50 N.m (37 lb ft), use a NEW seal.
9. Lower the vehicle.
10. Fill in ATF until ATF drips out the transmission fluid filler tube.
11. Raise the vehicle.
12. Install and tighten the transmission fluid check bolt to 8 N.m (71 lb in), use a NEW O-Ring.

Check

1. Test conditions: Vehicle must be on a flat surface. Selector lever in position "P". Engine OFF. Connect diagnostic tool. Delete fault memory.
2. Remove the transmission oil filler plug (1).
3. Start engine and allow to run until the end of the test.
4. Move through selector lever positions with the foot brake depressed. Switch selector lever from position "P" to "D" and back to "P". Hold each position for at least 2 seconds. Repeat this process twice. Check transmission fluid temperature with diagnostic tool. Raise the vehicle. Remove the fluid check bolt (5). DISCARD the O-Ring. Drain transmission fluid until it drips out of the transmission fluid filler overflow tube (3), otherwise add transmission fluid until it drips out of the transmission fluid filler overflow tube. Install the fluid check bolt with NEW O-ring and tighten to 8 N.m (71 lb in). Lower the vehicle. Top up 0.4 liters of ATF. Switch off engine.
5. Install the transmission oil filler plug with NEW seal ring and tighten to 40 N.m (30 lb ft).

Special Tools

1. DT-498-B Pressure Measuring Equipment
2. DT-6329 Adapter

For equivalent regional tools, refer to Special Tools .

Note. Due to the risk of overheating, checking at full load must not take longer than 5 seconds. Add a pause for cooling down. The oil level in the transmission must be correct.

1. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#general-information__lifting-and-jacking-the-vehicle) .
2. Remove the lower engine compartment cover.
3. Remove the upper plug (A). (The front torque rod has been removed in the illustration to give a better view of the connections.)
4. Fit DT-6329 adapter (A).
5. Fit DT-498-B equipment (B) on connection (A).
6. Lower the vehicle.
7. Connect the scan tool and check the oil temperature.
8. Check the oil pressure in selector lever position "D". Start the engine. Move the selector lever to position "D". Check the oil pressure at idling speed and at full load - air conditioning and lighting disengaged. Desired value idling speed (foot brake not applied): 370-410 kPa (53.6-59.5 psi). Desired value full load: 1350-1460 kPa (195.8-211.7 psi). Switch off the engine after the check.
9. Raise the vehicle.
10. Remove the oil pressure gauge (B).
11. Remove the connection (A).
12. Install the upper plug (A) with a NEW sealing ring and tighten to 10 N.m (89 lb in).
13. Remove the lower plug (B).
14. Install DT-6329 adapter (A).
15. Install DT-498-B equipment (B) on connection (A).
16. Lower the vehicle.
17. Connect the scan tool and check the oil temperature.
18. Check the oil pressure in selector lever position "R". Start the engine. Move the selector lever to position "R". Check the oil pressure at idling speed and at full load - air conditioning and lighting disengaged. Desired value idling speed (foot brake not applied): 570-660 kPa (82.7-95.7 psi). Desired value full load: 190-213 kPa (27.5-30.9 psi). Switch off the engine after the check.
19. Raise the vehicle.
20. Remove the oil pressure gauge (B).
21. Remove the connection (A).
22. Install the lower plug (B) with a NEW sealing ring and tighten to 10 N.m (89 lb in).
23. Lower the vehicle.
24. Remove the scan tool.

Road Test

Note. The Road Test procedure should be performed only as part of the Symptom Diagnosis. Refer to Symptoms - Automatic Transmission .

The following test provides a method of evaluating the condition of the automatic transmission. The test is structured so that most driving conditions would be achieved. The test is divided into the following parts

1. Visual inspection of transmission fluid leaks
2. Electrical function check
3. Adaptive learning
4. Confirm customer complaint by driving
5. Check oil level and oil quality

Note. Complete the test in the sequence given. Incomplete testing cannot guarantee an accurate evaluation.

Before the road test, ensure the following

1. The engine is performing properly
2. Tire pressure is correct
3. Vent hose is correctly mounted.

During the road test

1. Perform the test only when traffic conditions permit
2. Operate the vehicle in a controlled, safe manner
3. Observe all traffic regulations.
4. View the scan tool data while conducting this test.
5. Observe any unusual sounds or smells.

After the road test, check the following

1. Inspect for proper transmission fluid level and check oil quality. Refer to «Transmission Fluid Level and Condition Check»(/buick/regal/v-2009-2013/remont/automatic-trans/#automatic-transmission-af40-6__transmission-fluid-level-and-condition-check) .
2. Inspect for any diagnostic trouble codes (DTCs) that may have set during the testing. Refer to the applicable DTC.
3. Monitor the scan tool data for any abnormal readings or data.
4. Inspect for fluid leaks. Refer to «Fluid Leak Diagnosis»(/buick/regal/v-2009-2013/remont/automatic-trans/#automatic-transmission-af40-6) .

Electrical Function Check

Perform this procedure first in order to ensure the electronic transmission components are functioning properly. If these components are not checked, a simple electrical condition could be misdiagnosed.

1. Connect the scan tool.
2. Ensure the selector lever is in PARK and set the parking brake.
3. Start the engine.
4. Verify that scan tool data can be obtained. Refer to «Control Module References»(/buick/regal/v-2009-2013/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for typical data values. Data that is questionable may indicate a concern.
5. Monitor the TCC brake switch parameter while applying and releasing the brake pedal. The scan tool should display: Open when the brake pedal is applied. Closed when the brake pedal is released.
6. Check the garage shifts. Apply the brake pedal and ensure the parking brake is set. Move the gear selector through the following ranges: PARK to REVERSE REVERSE to NEUTRAL NEUTRAL to DRIVE Pause 2 to 3 seconds in each shift position. NOTE: Harsh engagement may be caused by any of the following conditions: Verify the gear engagements are immediate and not harsh. High engine idle speed - Compare engine idle speed to desired idle speed. High pressure will cause harsh shifts. A default condition caused by certain DTCs that result in maximum line pressure to prevent clutch slippage. NOTE: Soft or delayed engagement may be caused by any of the following conditions: Low idle speed - Compare engine idle speed to desired idle speed. Low fluid level. Low pressure will cause soft or delayed shifts. Cold transmission fluid temperature (TFT) - Use the scan tool to determine TFT. Selector linkage - Inspect and adjust as necessary. Verify the gear engagements are immediate and not harsh.
7. Monitor transmission range on the scan tool, engine data list. Apply the brake pedal and ensure the parking brake is set. Move the gear selector through all ranges. Pause 2 to 3 seconds in each range. Return gear selector to PARK. Verify that all selector positions match the scan tool display.
8. Check throttle position input. Apply the brake pedal and ensure the parking brake is set. Ensure the selector lever is in PARK. Monitor the scan tool Calc. Throttle Position while increasing and decreasing engine speed with the throttle pedal. The scan tool Calc. Throttle Position percentage should increase and decrease with engine speed.

If any of the above checks do not perform properly, record the result for reference after completion of the road test.

Adaptive Learning

Start driving the car and make the adaptive learning. Refer to Transmission Adaptive Functions .

Confirm Customer Complaint by Driving

Continue driving to verify the customer complaint. It might be useful to use manual shifting in order to verify the problem.

Check Oil Level and Oil Quality

After the driving is finalized and the complaint has been recorded

1. Check fluid level. Refer to «Transmission Fluid Level and Condition Check»(/buick/regal/v-2009-2013/remont/automatic-trans/#automatic-transmission-af40-6__transmission-fluid-level-and-condition-check) .
2. Check oil quality. If the oil is milky there is a water leakage into the transmission. Check the vent hose. If the oil smells burnt and its color is dark some disc may have been overloaded.
3. If the oil quality is too bad, change oil, make a new adaptive driving and the check if the problem is still there.

Torque Converter Diagnosis

The torque converter clutch (TCC) is applied by fluid pressure, which is controlled by a pulse width modulated (PWM) solenoid valve. This solenoid valve is located inside of the automatic transmission assembly. The solenoid valve is controlled through a combination of computer controlled switches and sensors.

Torque Converter Stator

The torque converter stator roller clutch can have two different malfunctions.

1. The stator assembly freewheels in both directions.
2. The stator assembly remains locked up at all times.

Poor Acceleration at Low Speed

If the stator is freewheeling at all times, the car tends to have poor acceleration from a standstill. At speeds above 50-55 km/h (30-35 mph), the car may act normally. For poor acceleration, you should first determine that the exhaust system is not blocked, and the transmission is in First gear when starting out.

If the engine freely accelerates to high RPM in NEUTRAL, you can assume that the engine and the exhaust system are normal. Check for poor performance in DRIVE and REVERSE to help determine if the stator is freewheeling at all times.

Poor Acceleration at High Speed

If the stator is locked up at all times, performance is normal when accelerating from a standstill. Engine RPM and car speed are limited or restricted at high speeds. Visual examination of the converter may reveal a blue color from overheating.

If the converter has been removed, you can check the stator roller clutch by inserting a finger into the splined inner race of the roller clutch and trying to turn the race in both directions. You should be able to freely turn the inner race clockwise, but you should have difficulty in moving the inner race counterclockwise or you may be unable to move the race at all.

Noise

Note. Do not confuse this noise with pump whine noise, which is usually noticeable in PARK, NEUTRAL and all other gear ranges. Pump whine will vary with line pressure.

You may notice a torque converter whine when the vehicle is stopped and the transmission is in DRIVE or REVERSE. This noise will increase as you increase the engine RPM. The noise will stop when the vehicle is moving or when you apply the torque converter clutch, because both halves of the converter are turning at the same speed.

Perform a stall test to make sure the noise is actually coming from the converter

1. Place your foot on the brake.
2. Put the gear selector in DRIVE.
3. Depress the accelerator to approximately 1, 200 RPM for no more than 6 seconds.

A torque converter noise will increase under this load.

Torque Converter Clutch Shudder

The key to diagnosing TCC shudder is to note when it happens and under what conditions.

TCC shudder which is caused by the transmission should only occur during the apply or the release of the converter clutch. Shudder should never occur after the TCC plate is fully applied.

If the shudder occurs while the TCC is applying, the problem can be within the transmission or the torque converter. Something is causing one of the following conditions to occur

1. Something is not allowing the clutch to become fully engaged.
2. Something is not allowing the clutch to release.
3. The clutch is releasing and applying at the same time.

One of the following conditions may be causing the problem to occur

1. Leaking turbine shaft seals
2. A restricted release orifice
3. A distorted clutch or housing surface due to long converter bolts
4. Defective friction material on the TCC plate

If Shudder Occurs After TCC has Applied

If shudder occurs after the TCC has applied, most of the time there is nothing wrong with the transmission.

As mentioned above, the TCC is not likely to slip after the TCC has been applied. Engine problems may go unnoticed under light throttle and load, but they become noticeable after the TCC apply when going up a hill or accelerating. This is due to the mechanical coupling between the engine and the transmission.

Once TCC is applied, there is no torque converter, fluid coupling, assistance. Engine or driveline vibrations could be unnoticeable before TCC engagement.

Inspect the following components in order to avoid misdiagnosis of TCC shudder. An inspection will also avoid the unnecessary disassembly of a transmission or the unnecessary replacement of a torque converter.

1. Spark plugs - Inspect for cracks, high resistance or a broken insulator.
2. Coil - Look for a black discoloration on the bottom of the coil. This indicates arcing while the engine is misfiring.
3. Fuel injector - The filter may be plugged.
4. Vacuum leak - The engine will not get a correct amount of fuel. The mixture may run rich or lean depending on where the leak occurs.
5. EGR valve (Petrol) - The valve may let in too much or too little unburnable exhaust gas and could cause the engine to run rich or lean.
6. MAP sensor - Like a vacuum leak, the engine will not get the correct amount of fuel for proper engine operation.
7. Carbon on the intake valves - Carbon restricts the proper flow of air/fuel mixture into the cylinders.
8. Flat cam - Valves do not open enough to let the proper fuel/air mixture into the cylinders.
9. Oxygen sensor - This sensor may command the engine too rich or too lean for too long.
10. Fuel pressure - This may be too low.
11. Engine mounts - Vibration of the mounts can be multiplied by TCC engagement.
12. Axle joints - Check for vibration.
13. TP Sensor (Petrol) - The TCC apply and release depends on the TP Sensor in many engines. If the TP Sensor is out of specification, TCC may remain applied during initial engine loading.
14. Cylinder balance - Bad piston rings or poorly sealing valves can cause low power in a cylinder.
15. Fuel contamination - This causes poor engine performance.

Torque Converter Evaluation and Diagnosis

Replace the torque converter if any of the following conditions exist

1. External leaks appear in the hub weld area.
2. The converter hub is scored or damaged.
3. The converter pilot is broken, damaged, or fits poorly into the crankshaft.
4. You discover steel particles after flushing the cooler and the cooler lines.
5. The pump is damaged, or you discover steel particles in the converter.
6. The vehicle has TCC shudder and/or no TCC apply. Replace the torque converter only after all hydraulic and electrical diagnoses have been made. The converter clutch material may be glazed.
7. The converter has an imbalance which cannot be corrected.
8. The converter is contaminated with engine coolant which contains antifreeze.
9. An internal failure occurs in the stator roller clutch.
10. You notice excessive end play.
11. Overheating produces heavy debris in the clutch.
12. You discover steel particles or clutch lining material in the fluid filter or on the magnet, when no internal parts in the unit are worn or damaged. This condition indicates that lining material came from the converter.

Do not replace the torque converter if you discover any of the following symptoms

1. The oil has an odor or the oil is discolored, even though metal or clutch facing particles are not present.
2. The threads in one or more of the converter bolt holds are damaged. Correct the condition with a new thread inset.
3. Transmission failure did not display evidence of damaged or worn internal parts, steel particles or clutch plate lining material in the unit and inside the fluid filter. If the vehicle has been exposed to high mileage only. An exception may exist where the lining of the torque converter clutch dampener plate has seen excess wear by vehicles operated in heavy and/or constant traffic, such as taxi, delivery, or police use.

Noise and Vibration Analysis

A noise or vibration that is noticeable when the vehicle is in motion MAY NOT be the result of the transmission. Refer to the Symptoms - Vibration Diagnosis and Correction procedure.

If noise or vibration is noticeable in PARK and NEUTRAL with the engine at idle, but is less noticeable as RPM increases, the vibration may be a result of poor engine performance.

1. Vibration may also be caused by a small amount of water inside the converter.
2. Inspect the shift control cable mounting.
3. Inspect the engine and transmission mounts for damage and loose bolts.
4. Inspect the transmission case mounting holes for the following conditions: Missing bolts, nuts, and studs Stripped threads Cracks
5. Inspect the flywheel for the following conditions: Missing or loose bolts Cracks Imbalance
6. If the noise or vibration is noticeable in PARK and NEUTRAL with the engine at idle, but is more noticeable as RPM increases, the vibration may be an engine imbalance or a transmission imbalance.

General Method

1. Verify that the leak is transmission fluid.
2. Thoroughly clean the suspected leak area.
3. Operate the vehicle for 24 km (15 mi), or until normal operating temperatures are reached.
4. Park the vehicle over clean paper or cardboard.
5. Shut OFF the engine.
6. Look for fluid spots on the paper.
7. Make the necessary repairs.

Powder Method

1. Thoroughly clean the suspected leak area with solvent.
2. Apply an aerosol type leak tracing powder to the suspected leak area.
3. Operate the vehicle for 24 km (15 mi), or until normal operating temperatures are reached.
4. Shut OFF the engine.
5. Inspect the suspected leak area.
6. Trace the leak path through the powder in order to find the source of the leak.
7. Make the necessary repairs.

Dye and Black Light Method

A fluid dye and black light kit is available from various tool manufacturers.

1. Follow the manufacturer instructions in order to determine the amount of dye to use.
2. Operate the vehicle for 24 km (15 mi) or until normal operating temperatures are reached.
3. Detect the leak with the black light.
4. Make the necessary repairs.

Find the Cause of the Leak

Pinpoint the leak and trace the leak back to the source. You must determine the cause of the leak in order to repair the leak properly. For example, if you replace a gasket, but the sealing flange is bent, the new gasket will not repair the leak. You must also repair the bent flange. Before you attempt to repair a leak, check for the following conditions, and make repairs as necessary

Gaskets

1. Fluid level/pressure is too high.
2. Plugged vent or drain-back holes.
3. Improperly tightened fasteners.
4. Dirty or damaged threads.
5. Warped flanges or sealing surface.
6. Scratches, burrs, or other damage to the sealing surface.
7. Damaged or worn gasket.
8. Cracking or porosity of the component.
9. Improper sealant used, where applicable.
10. Incorrect gasket.

Seals

1. Fluid level/pressure is too high.
2. Plugged vent or drain-back holes.
3. Damaged or worn seal.
4. Cracks in component.
5. Manual shaft or output shaft surface is scratched, nicked, or damaged.
6. Loose or worn bearing causing excess seal wear.

Possible Points of Fluid Leaks

Transmission Valve Body Cover

1. Incorrectly tightened bolts.
2. Improperly installed or damaged gasket/seal.
3. Damaged mounting face.
4. Incorrect gasket seal.

Transmission Case Leak

1. Loose or damaged oil cooler lines/seals.
2. Worn or damaged axle shaft oil seal.
3. Loose line pressure pipe plug or fluid level pipe plug.

Leak at the Transmission Vent

1. Overfilled system.
2. Water or coolant in the fluid. The fluid will appear milky. Check vent hose mounting.
3. Plugged vent.

1. DT-45096 TransFlow Cooler Flush Machine
2. DT-45096-30 TransFlow Adapter

For equivalent regional tools, refer to Special Tools .

GM studies indicate that plugged or restricted transmission oil coolers and pipes cause insufficient transmission lubrication and elevated operating temperatures which can lead to premature transmission failure. Many repeat repair cases could have been prevented by following published procedures for transmission oil cooler flushing and flow checking. This procedure includes flow checking and flushing the auxiliary transmission oil cooler, if equipped.

Note. Use the DT-45096 TransFlow Cooler Flush Machine or equivalent to flush and flow test the transmission oil cooler and the oil cooler pipes after the transaxle is removed for repairs or replacement. Use only GM Goodwrench DEXRON VI automatic transmission fluid in the DT-45096 TransFlow Cooler Flush Machine. The AF40-6 uses AW-1 automatic transmission fluid. After completing the flushing and flow test procedure, remove the residual DEXRON VI left in the oil cooler by carefully blowing out with compressed air. Time allowance for performing the cooler flow checking and flushing procedure is included in the appropriate labor time guide operations. The service procedure steps for oil cooler flushing and flow testing are as follows

Cooler Flow Check and Flushing Steps

1. Machine Set-up
2. Determine Minimum Flow Rate
3. Back Flush
4. Forward Flush
5. Flow Test
6. Code Recording Procedure
7. Clean-up

Special Tools

1. DT-45096 TransFlow Cooler Flush Machine
2. DT-45096-30 TransFlow Adapter
3. Shop air supply with water/oil filters, regulator and pressure gauge - minimum 90 psi
4. Eye protection
5. Rubber gloves

Machine Set-up

1. Verify that the main power switch (1) is in the OFF position.
2. Place the main function switch (2) in the IDLE position.
3. Connect DT-45096 flush machine to the vehicle 12V DC power source by connecting the red battery clip to the positive, +, battery post on the vehicle and connect the negative lead to a known good chassis ground.
4. Turn the main power switch to the ON position.
5. Fill the supply tank with Dexron®VI through the fill port.
6. Reinstall and tighten the fill cap.
7. Connect a shop air supply hose to the quick-disconnect on the rear panel marked SUPPLY AIR.

Determine Minimum Flow Rate

1. From the machine display, identify the temperature of the automatic transmission fluid that is stored in the supply vessel of DT-45096 flush machine.
2. Determine whether the transmission oil cooler is steel or aluminum by using a magnet (1) at the cooler flange (2) at the radiator.
3. Refer to the table below. Using the temperature from step 1, locate on either the Steel MINIMUM Flow Rate table or the Aluminum MINIMUM Flow Rate table the minimum flow rate in gallons per minutes (GPM). Record the minimum flow rate in GPMs and the supply fluid temperature for further reference. Example: Fluid temperature: 75°F Cooler type: Steel The MINIMUM flow rate for this example would be 0.8 GPM.
4. Inspect transmission oil cooler lines for damage or kinks that could cause restricted oil flow. Repair as needed and refer to the appropriate GM service manual procedures.

Minimum Flow Rate in Gallons Per Minute (GPM)

Back Flush Procedure

1. Install the DT-45096-30 adapter onto the oil cooler lines.
2. Connect the black supply hose (1) to the adapter connected to the return line, bottom hose of the transmission oil cooler.
3. Connect the clear waste hose (2) to the adapter connected to the supply line, top hose from the transmission oil cooler. The above connections are the reverse flow or back-flush direction.
4. Turn the main function switch to the FLUSH position. Allow the machine to operate for 30 seconds.
5. Turn the main function switch to the IDLE position and allow the supply vessel pressure to dissipate.

Forward Flush

1. Disconnect the DT-45096 flush machine at the hose couplings at the adapters and switch the hoses. The black hose (2) to the oil cooler supply hose and the clear hose (1) to the oil cooler return hose. The above connections are now in the normal flow direction.
2. Turn the main function switch to the FLUSH position and allow machine to operate for 30 seconds.

Flow Test

1. Turn the main function switch to the FLOW position and allow the oil to flow for 15 seconds. Observe and note the flow rate; this is the TESTED flow rate.
2. Compare the TESTED flow rate to the MINIMUM flow rate information previously recorded. If the TESTED flow rate is equal to or greater than the MINIMUM flow rate recorded, the oil cooling system is functioning properly. Perform Code Recording Procedure. If the TESTED flow rate is less than the MINIMUM flow rate previously recorded, repeat the back flush and forward flush procedures.
3. If the TESTED flow rate is less than the MINIMUM flow rate after the second test, perform Code Recording Procedure. Replace the transmission oil cooler. Reconnect supply and waste hoses to the cooler lines in the normal flow direction. Perform Flow Test. Perform Code Recording Procedure.

Code Recording Procedure

1. Turn the main function switch to the CODE position.
2. Record TESTED flow rate, temperature, cycle and seven-character flow code information on repair order.

Clean-up

1. Turn the main function switch to the IDLE position and allow the supply vessel pressure to dissipate.
2. Turn the main power switch to the OFF position.
3. Disconnect the supply and waste hoses and the 12-volt power source from the vehicle.
4. Disconnect the air supply hose from DT-45096 flush machine.
5. Dispose of the waste ATF in accordance with all applicable federal, state, and local requirements.
6. Clean the residual DEXRON VI from the transmission oil cooler, using compressed air to blow out the transmission oil cooler.

Transmission Overheats

Transmission Overheats

Automatic Transmission Fluid Leaks

Automatic Transmission Fluid Leaks

Scheme 35

Transmission Control Lever Knob Replacement

Scheme 36

Transmission Control Lever Boot Replacement

Scheme 37

Transmission Control Replacement

Range Selector Lever Cable Adjustment

This style cable does not require any adjustment. To reset the range selector cable after servicing perform the following procedure

1. Ensure that the shift lever and the shifter are in the Park position.
2. Secure the cable adjustment lock into place.

Scheme 38

Range Selector Lever Cable Replacement

Scheme 39

Automatic Transmission Range Selector Lever Replacement

Scheme 40

Transmission Control Module Replacement

Scheme 41

Transmission Front Mount Replacement

Scheme 42

Transmission Rear Mount Replacement

Removal Procedure

1. Loosen the rear part of the front wheelhouse front liner. Refer to «Front Wheelhouse Front Liner Replacement»(/buick/regal/v-2009-2013/remont/frames-subframes-crossmembers/#frame-and-underbody) .
2. Remove front transmission mount to subframe fastener. Refer to «Transmission Front Mount Replacement»(/buick/regal/v-2009-2013/remont/automatic-trans/#automatic-transmission-af40-6) .
3. Remove the battery tray. Refer to «Battery Tray Replacement»(/buick/regal/v-2009-2013/remont/charging-system/#battery-charging-system-and-starting-system-non-hybrid) .
4. Support the transmission using a jack.
5. Remove transmission mount fasteners (1).
6. Lower the transmission.
7. Remove transmission mount fasteners (2).
8. Remove the left side transmission mount (4).

Installation Procedure

1. Install the left side transmission mount (4).
2. Install the transmission mount fasteners (2) and tighten to 22 N.m (16 lb ft).
3. Lift the transmission.
4. Loosely install the transmission mount fasteners (1) with NEW bolts.
5. Install the front transmission mount to subframe fastener. Refer to «Transmission Front Mount Replacement»(/buick/regal/v-2009-2013/remont/automatic-trans/#automatic-transmission-af40-6) .
6. Tighten the transmission mount fasteners (1) to 50 N.m (37 lb ft) plus 60 degrees plus 15 degrees.
7. Install the rear part of the front wheelhouse front liner. Refer to «Front Wheelhouse Front Liner Replacement»(/buick/regal/v-2009-2013/remont/frames-subframes-crossmembers/#frame-and-underbody) .
8. Install the battery tray. Refer to «Battery Tray Replacement»(/buick/regal/v-2009-2013/remont/charging-system/#battery-charging-system-and-starting-system-non-hybrid) .

Scheme 43

Control Valve Body Cover Replacement

Scheme 44

1. Remove the control valve body cover. Refer to «Control Valve Body Cover Replacement»(/buick/regal/v-2009-2013/remont/automatic-trans/#automatic-transmission-af40-6) .
2. Remove the wiring harness for the solenoid valves. The illustration shows how to use a screwdriver for removing the different connectors. Remove 8 connectors from the solenoid valves (1). Disconnect the 2 connectors from the engine speed sensors (2). Remove the wiring harness from the 2 retaining clips (3).
3. Disconnect the engine speed sensor connectors. Remove the connectors from the 2 mountings (4).
4. Remove the temperature sensor. Remove the screw (1). Lift away the attaching plate (2). Remove the temperature sensor (3).
5. Move the wiring harness for the solenoid valves and the wiring harness for the engine speed sensors aside.
6. Remove the cover (1). Remove the screws (2). Remove the gasket (3).
7. Remove the valve housing. Loosen the fasteners in the specified order. Remove the fasteners.
8. Lower the vehicle.
9. Disconnect the clutch rod (1).
10. Carefully lift the valve housing upwards.

Scheme 45

1. Clean the sealing surfaces.
2. Clean the threads (arrows).
3. Install the valve housing. Connect the clutch rod (1). Install the 6 fasteners.
4. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#general-information__lifting-and-jacking-the-vehicle) .
5. Install the cover. Install a new gasket (3). Install the cover (1). Install two screws (2).
6. Install the valve housing.
7. Tighten the 8 fasteners (arrows) in the specified order and tighten to 10 N.m (88 lb in).
8. Install the temperature sensor (3). Lubricate the temperature sensor O-ring with gearbox oil. Install the attaching plate (2). Tighten the fastener (1) to 10 N.m (88 lb in).
9. Connect the engine speed sensor connectors. Install the connectors to the two mountings (4).
10. Connect the connector for the solenoid valves. Secure the wiring harness in the 2 retaining clips (3). Connect the 2 connectors for the engine speed sensors (2). Connect the 8 connectors for the solenoid valves (1).
11. Install the control valve body. Refer to «Control Valve Body Cover Replacement»(/buick/regal/v-2009-2013/remont/automatic-trans/#automatic-transmission-af40-6) .
12. Lower the vehicle.

Scheme 46

Transmission Fluid Cooler Hose/Pipe Quick-Connect Fitting Disconnection and Connection

1. DT-41239-1A Cooler Line Seal Installer
2. DT-45201 Cooler Line Seal Remover

For equivalent regional tools, refer to Special Tools .

1. Raise the vehicle. Refer to «Lifting and Jacking the Vehicle»(/buick/regal/v-2009-2013/remont/ignition-switchsteering-lock/#general-information__lifting-and-jacking-the-vehicle) .
2. Place a drain pan or suitable container under the vehicle.
3. Remove the transaxle oil cooler line assembly nut from the transaxle.
4. Disconnect the transaxle oil cooler lines from the vehicle.
5. Insert the collet piece (2) of the DT-45201 Cooler Line Seal Remover into the cooler line seal.
6. Insert the forcing screw piece (1) of the DT-45201 Cooler Line Seal Remover into the collet (2).
7. Tighten the forcing screw (1) until snug.
8. Thread the collar piece (1) of the DT-45201 Cooler Line Seal Remover onto the collet (3) until snug.
9. Turn the collar clockwise in order to remove the cooler line seal (87).
10. Discard the seal (87).
11. Clean the case bores for the cooler line seals.

1. Insert a new transaxle cooler line seal into the case bore.
2. Remove the nub from the DT-41239-1A Cooler Line Seal Installer.
3. Install the nub of the DT-41239-1A Cooler Line Seal Installer on the transaxle cooler line seal.
4. Tap the new transaxle cooler line seal into the case bore.
5. Install the transaxle oil cooler line assembly to the transaxle.
6. Install the transaxle oil cooler line assembly nut and tighten to 9 N.m (80 lb in).
7. Lower the vehicle.
8. Add fluid to the transaxle. Refer to «Adhesives, Fluids, Lubricants, and Sealers»(/buick/regal/v-2009-2013/remont/automatic-trans/#automatic-transmission-af40-6__adhesives-fluids-lubricants-and-sealers)
9. Start the engine and check for leaks.

Scheme 47

Transmission Fluid Cooler Hose Replacement

Scheme 48

Front Axle Shaft Seal Replacement - Right Side

Scheme 49

Front Axle Shaft Seal Replacement - Left Side

Scheme 50

Torque Converter Replacement

Scheme 51

Torque Converter Fluid Seal Replacement

Transmission Replacement

Special Tools

EN-47649 Engine Support Fixture

For equivalent regional tools, refer to Special Tools .

1. Remove the battery tray. Refer to «Battery Tray Replacement»(/buick/regal/v-2009-2013/remont/charging-system/#battery-charging-system-and-starting-system-non-hybrid) .
2. Remove the connector (1) to the transmission control module.
3. Remove the shift lever cable from the selector on the transmission. Refer to «Range Selector Lever Cable Replacement»(/buick/regal/v-2009-2013/remont/automatic-trans/#automatic-transmission-af40-6) .
4. Remove the upper transmission fasteners (1).
5. Support the engine with EN-47649 support fixture. Refer to «Engine Support Fixture»(/buick/regal/v-2009-2013/remont/mechanical/#engine-mechanical-20l-repair-instructions-on-vehicle) .
6. Remove the exhaust front pipe. Refer to «Exhaust Front Pipe Replacement (LHU)»(/buick/regal/v-2009-2013/remont/exhaust/#engine-exhaust-system) , «Exhaust Front Pipe Replacement (LDK or LHU)»(/buick/regal/v-2009-2013/remont/exhaust/#engine-exhaust-system) .
7. Remove the subframe. Refer to «Drivetrain and Front Suspension Frame Replacement»(/buick/regal/v-2009-2013/remont/frames-subframes-crossmembers/#frame-and-underbody) .
8. Remove the transmission front mount. Refer to «Transmission Front Mount Replacement»(/buick/regal/v-2009-2013/remont/automatic-trans/#automatic-transmission-af40-6) .
9. Remove the transmission rear mount bracket. Refer to «Transmission Rear Mount Replacement»(/buick/regal/v-2009-2013/remont/automatic-trans/#automatic-transmission-af40-6) .
10. Drain the transmission fluid. Refer to «Transmission Fluid Level and Condition Check»(/buick/regal/v-2009-2013/remont/automatic-trans/#automatic-transmission-af40-6__transmission-fluid-level-and-condition-check) .
11. Remove the right driveshaft from the intermediate shaft then remove the intermediate shaft. Refer to «Intermediate Shaft Replacement»(/buick/regal/v-2009-2013/remont/axle-shafts/#wheel-drive-shafts) .
12. Remove the left driveshaft from the transmission. Refer to «Front Wheel Drive Shaft Replacement - Left Side (GNA)»(/buick/regal/v-2009-2013/remont/axle-shafts/#wheel-drive-shafts) .
13. Remove the starter motor. Refer to «Starter Replacement (LDK Or LHU)»(/buick/regal/v-2009-2013/remont/charging-system/#battery-charging-system-and-starting-system-non-hybrid) , «Starter Replacement (LEA)»(/buick/regal/v-2009-2013/remont/charging-system/#battery-charging-system-and-starting-system-non-hybrid) .
14. Remove the fasteners (1) to the converter.
15. Remove the oil cooler hose connection (1) from the transmission.
16. Lower the vehicle.
17. Remove the fasteners to the transmission mount bracket left side. Refer to «Transmission Mount Replacement - Left Side»(/buick/regal/v-2009-2013/remont/automatic-trans/#automatic-transmission-af40-6) .
18. Lower the engine enough to access the transmission.
19. Raise the vehicle.
20. Support the transmission with a suitable transmission jack.
21. Remove the lower transmission fasteners (1).
22. Remove the lower transmission fasteners (1).
23. Separate the transmission from the engine.
24. Secure the torque converter against falling, attach the DT-6388 holder.
25. Remove the transmission from the transmission jack.
26. Flush and flow test the transmission oil cooler and lines. Refer to «Transmission Fluid Cooler Flushing and Flow Test»(/buick/regal/v-2009-2013/remont/automatic-trans/#automatic-transmission-af40-6) .

1. Place the transmission on the transmission jack.
2. Lubricate the centering pin on the converter and the two guiding sleeves.
3. Remove DT-6388 holder.
4. Check torque converter position. Refer to «Torque Converter Replacement»(/buick/regal/v-2009-2013/remont/automatic-trans/#automatic-transmission-af40-6) .
5. Attach the transmission to the engine.
6. Install the lower transmission fasteners (1) and tighten to 60 N.m (44 lb ft).
7. Install the lower transmission fasteners (1) and tighten to 60 N.m (44 lb ft).
8. Remove the transmission jack.
9. Lower the vehicle.
10. Raise the engine to the correct level with the engine support fixture.
11. Install the fasteners to the transmission mount bracket left side. Refer to «Transmission Mount Replacement - Left Side»(/buick/regal/v-2009-2013/remont/automatic-trans/#automatic-transmission-af40-6)
12. Remove the engine support fixture.
13. Install the upper transmission fasteners (1) and tighten to 60 N.m (44 lb ft).
14. Install the shift lever cable from the selector on the transmission. Refer to «Range Selector Lever Cable Replacement»(/buick/regal/v-2009-2013/remont/automatic-trans/#automatic-transmission-af40-6) .
15. Install the connector to the transmission control module.
16. Raise the vehicle.
17. Install the fastener (1) to the converter. Apply locking agent on the bolts and tighten to 60 N.m (44 lb ft)
18. Install the starter motor. Refer to «Starter Replacement (LDK Or LHU)»(/buick/regal/v-2009-2013/remont/charging-system/#battery-charging-system-and-starting-system-non-hybrid) , «Starter Replacement (LEA)»(/buick/regal/v-2009-2013/remont/charging-system/#battery-charging-system-and-starting-system-non-hybrid) .
19. Install the oil cooler hose connection (1) to the transmission and tighten to 7 N.m (62 lb in).
20. Install the transmission rear mount bracket. Refer to «Transmission Rear Mount Replacement»(/buick/regal/v-2009-2013/remont/automatic-trans/#automatic-transmission-af40-6) .
21. Install the transmission front mount. Refer to «Transmission Front Mount Replacement»(/buick/regal/v-2009-2013/remont/automatic-trans/#automatic-transmission-af40-6) .
22. Install the intermediate shaft then install the right driveshaft to the intermediate shaft. Refer to «Intermediate Shaft Replacement»(/buick/regal/v-2009-2013/remont/axle-shafts/#wheel-drive-shafts) .
23. Install the left driveshaft to the transmission. Refer to «Front Wheel Drive Shaft Replacement - Left Side (GNA)»(/buick/regal/v-2009-2013/remont/axle-shafts/#wheel-drive-shafts) .
24. Install the subframe. Refer to «Drivetrain and Front Suspension Frame Replacement»(/buick/regal/v-2009-2013/remont/frames-subframes-crossmembers/#frame-and-underbody) .
25. Install the exhaust front pipe. Refer to «Exhaust Front Pipe Replacement (LHU)»(/buick/regal/v-2009-2013/remont/exhaust/#engine-exhaust-system) , «Exhaust Front Pipe Replacement (LDK or LHU)»(/buick/regal/v-2009-2013/remont/exhaust/#engine-exhaust-system) .
26. Lower the vehicle.
27. Install the battery tray and battery. Refer to «Battery Tray Replacement»(/buick/regal/v-2009-2013/remont/charging-system/#battery-charging-system-and-starting-system-non-hybrid) .
28. Fill the transmission fluid. Refer to «Transmission Fluid Level and Condition Check»(/buick/regal/v-2009-2013/remont/automatic-trans/#automatic-transmission-af40-6__transmission-fluid-level-and-condition-check) .
29. If the transmission is replaced, it is necessary to make an adaption. Refer to «Transmission Adaptive Functions»(/buick/regal/v-2009-2013/remont/automatic-trans/#automatic-transmission-af40-6) and a SPS programming.

1. Remove the control valve body cover. Refer to «Control Valve Body Cover Replacement»(/buick/regal/v-2009-2013/remont/automatic-trans/#automatic-transmission-af40-6) .
2. Remove the control valve body. Refer to «Control Valve Body Replacement»(/buick/regal/v-2009-2013/remont/automatic-trans/#automatic-transmission-af40-6) .
3. Remove the transmission control module. Refer to «Transmission Control Module Replacement»(/buick/regal/v-2009-2013/remont/automatic-trans/#automatic-transmission-af40-6) .
4. Remove the wiring harness. Remove the clip (1). Lift out the wiring harness (2).

1. Install the wiring harness. Install a new seal (2) in the gearcase and an O-ring (1) on the connection.
2. Install the wiring harness (2). Ensure the connector's guide pin locates in the groove and install the clip (1).
3. Install the transmission control module. Refer to «Transmission Control Module Replacement»(/buick/regal/v-2009-2013/remont/automatic-trans/#automatic-transmission-af40-6) .
4. Install the control valve body. Refer to «Control Valve Body Replacement»(/buick/regal/v-2009-2013/remont/automatic-trans/#automatic-transmission-af40-6) .
5. Install the control valve body cover. Refer to «Control Valve Body Cover Replacement»(/buick/regal/v-2009-2013/remont/automatic-trans/#automatic-transmission-af40-6) .

Scheme 52

For automatic transmission AF40, the identification plate is on the top of the transmission housing.

Transmission Identification Information

Transmission General Description

The AF 40-6 automatic transmission is an electronic 6-speed automatic transmission with lock-up. The transmission is mounted directly against the engine and has a final drive with integrated differential. The power unit is transverse mounted with front-wheel drive. Gear positions P-R-N-D are selected with the selector lever mounted in the centre console. Manual up/downshifting is possible.

A special automatic transmission fluid must be used. The transmission does not have an oil dipstick. The drain plug has an extra, central check plug for checking the level that is connected to a rising tube that reaches up to the correct level in the box. Fill the oil through the conventional oil filler plug until the level is correct and oil runs out of the check plug hole in the rising tube. Measure the temperature when checking the level. The temperature is read using a scan tool.

The AF 40-6 transmission has planetary gears, disc clutches, brakes and torque converter with lock-up. The clutches and brakes are applied hydraulically. The hydraulic system is controlled by the Transmission Control Module (TCM) with the help of 8 solenoids, 2 shaft speed sensors and one oil temperature sensor. TCM communicates on the high speed bus.

The TCM is mounted directly on top of the transmission and has one connector to the car's electrical system and one directly to the transmission. The gear position sensor is a Hall sensor and is integrated in the control module. The TCM is mounted so that the selector lever shaft goes through the control module. The selector lever position can be calibrated with the scan tool, there is no mechanical adjustment.

The TCM controls the transmission according to its programming, the information from its own sensors and from other control modules. The control module adapts its control of the solenoids to compensate for normal wear in the transmission. The TCM is SPS programmable.

Shifting

The TCM can determine whether to leave a gear engaged or to change up or down. What it does is determined mainly by the gear that is currently engaged, the speed of the output shaft and the position of the accelerator pedal. The TCM changes gear by applying or releasing a friction element in the transmission. The application is regulated with PWM from the respective solenoid.

The gear can also be changed manually with the selector lever in D position if using the Tap Up/Tap Down switch. The switch is hardwired to the BCM which converts the information into a HSCAN message that is used by the TCM.

Lock Up

The torque converter clutch is activated at a steady speed when there is no need of torque amplification. If the brakes are applied or acceleration increases, the function will be deactivated.

Safety Features

To protect the transmission there are temperature programs to prevent overheating. The TCM can choose to raise the shift points and activate lock up more often if the oil temperature is too high.

The reverse gear will not be activated if the car is travelling faster than 7 km/h. If the power supply to the solenoids fails, it is still possible to drive the car. The gear position D/M gives 2nd gear and P-R-N will work as usual. In case of a major fault in the transmission, mechanical or electrical, the TCM will cut the supply to the solenoids in a controlled manner (limp home).

In case the TCM detects a failure it will go into emergency mode.

Special Gear Change Program

If an uphill gradient is detected, the gears will change at higher engine speeds and each gear will remain engaged for longer periods.

The Sport Mode can be engaged by a switch. Upon detecting the sport mode request TCM adapts the shift lines in order to enable a more progressive driving.

Transmission Component and System Description

Gearbox functions can be divided into three parts

1. Mechanical Components
2. Hydraulic Components
3. Control System

Mechanical Components

1. Torque converter with lock-up clutch
2. 2 planetary gear units, of which the rear is double.
3. 3 disc clutches
4. 1 band type brake
5. 1 multi-disc brake
6. 1 free wheel
7. Final drive with differential

Scheme 53

Scheme 54

Control System

1. Linear solenoids
2. PWM solenoids
3. Speed sensors
4. Temperature sensor
5. Transmission Control Module including gear position sensor
6. Gear shift lever
7. Sport Mode Switch

General

If the automatic transmission or Transmission Control Module (TCM) is replaced, the Transmission Control Module (TCM) software is overwritten and the basic settings must be reset. This is done on a long test drive when the automatic transmission is warm by changing through all gears several times while "D" is engaged. After the long test drive, it may be possible that the Transmission Control Module (TCM) might not be completely finished with the running-in process. Thus, the customer must be informed that until the running-in process is complete, the transmission may not change gears or operate optimally. Until the running-in process is complete, there could be hard, jerky gearchanges, increased engine speed during gearchanges and delayed gearchanges.

Transmission Indicators and Messages

The following transmission-related indicators and messages may be displayed on the Driving Information Center (DIC). For a complete listing and description of all vehicle indicators and messages, refer to Indicator/Warning Message Description and Operation .

TRANSMISSION HOT IDLE ENGINE: This message is displayed if the temperature exceeds 150°C for longer than 2 seconds.

SERVICE TRANSMISSION: This message displays when there is a problem with the transmission.

Scheme 55

The TCM (2) is mounted directly on top of the transmission (1). The selector lever is integrated in the control module. The TCM is mounted so that the selector lever shaft goes through the control module. The selector lever position is calibrated with a scan tool, there is no mechanical adjustment.

An exterior 16-pin connector connects to the car's electrical system. Underneath the control module is another connector (22-pin) that connects directly to the transmission. The TCM makes contact with all the transmission solenoids and sensors here.

Note. Magnetic fields from e.g. magnets and from high-current cables, such as starter cables and cables to auxiliary equipment, can interfere with the gear position sensor. A rule of thumb is max 1A per mm in distance from the control module. A starter cable carrying a current of 200A must therefore be kept at least 20 cm away from the control module.

The TCM has a microprocessor with clock, RAM memory and a programmable ROM. An internal bus connects the processor and memory with the I/O unit. The I/O unit reads values from the A/D converter for analogue inputs, digital inputs and bus, as well as activates the transistors' output stages.

Adaptive values are saved in a non-volatile memory (ROM). When changing transmission, these values must be zeroed using scan tool. After changing TCM they will be zeroed automatically after adding the control module using the scan tool.

Scheme 56

The normally open solenoid valve is mounted in the transmission valve housing and is used by TCM when activating C2. The pressure to SLC2 is then raised from system pressure to D-pressure. The valve is also used to apply pressure to brake B2 for engine braking in 1st gear.

The control module activates the valve by applying B+ to it. The valve is powered from control module pin 5 in the connector in direct contact with the transmission on the bottom of the control module. The valve is grounded in the valve housing.

Overview S1 and S2 Solenoids

The normally closed solenoid valve is mounted in the transmission valve housing and is used together with S1 to apply pressure to brake B2 for engine braking in 1st gear.

The control module activates the valve by applying B+ to it. The valve is powered from control module pin 2 in the connector in direct contact with the transmission on the bottom of the control module. The valve is grounded in the valve housing.

Scheme 57

The PWM controlled solenoid valve is mounted in the transmission valve housing and controls the pressure in brake B1. The valve is active in gear positions P, R, N, D (gears 1, 3, 4 and 5).

The control module activates the valve by pulsing it with B+ (300 Hz PWM). The valve is powered from control module pin 21 in the connector that makes contact directly with the transmission on the bottom of the control module. The valve is grounded from pin 16. The current varies between 0-1000 mA. The solenoid is normally open and the hydraulic pressure drops as the current increases.

Overview SLB1, SLC1, SLC2, and SLC3 Solenoids

The PWM controlled solenoid valve is mounted in the transmission valve housing and controls the pressure in clutch C1. The valve is active in gear positions P, R, N, D (gears 5 and 6).

The control module activates the valve by pulsing it with B+ (300 Hz PWM). The valve is powered from control module pin 11 in the connector that makes contact directly with the transmission on the bottom of the control module. The valve is grounded from pin 10. The current varies between 0-1000 mA. The solenoid is normally open and the hydraulic pressure drops as the current increases.

The PWM controlled solenoid valve is mounted in the transmission valve housing and controls the pressure in clutch C2. The valve is active in gear positions P, R, N, D (gears 1, 2 and 3).

The control module activates the valve by pulsing it with B+ (300 Hz PWM). The valve is powered from control module pin 17 in the connector that makes contact directly with the transmission on the bottom of the control module. The valve is grounded from pin 18. The current varies between 0-1000 mA. The solenoid is normally open and the hydraulic pressure drops as the current increases.

The PWM controlled solenoid valve is mounted in the transmission valve housing and controls the pressure in clutch C3. The valve is active in gear positions P, N, D (gears 1, 2, 4 and 6).

The control module activates the valve by pulsing it with B+ (300 Hz PWM). The valve is powered from control module pin 14 in the connector that makes contact directly with the transmission on the bottom of the control module. The valve is grounded from pin 22. The current varies between 0-1000 mA. The solenoid is normally open and the hydraulic pressure drops as the current increases.

Scheme 58

The PWM controlled solenoid valve is mounted in the transmission valve housing and controls the transmission system pressure. The value is controlled so that it is not higher than what is currently needed for any friction element. Brake B2 does not have its own pressure control valve and is therefore supplied by SLT.

The control module activates the valve by pulsing it with B+ (300 Hz PWM). The valve is powered from control module pin 3 in the connector that makes contact directly with the transmission on the bottom of the control module. The valve is grounded from pin 1. The current varies between 0-1000 mA. The solenoid is normally open and the hydraulic pressure drops as the current increases.

Overview SLT and SLU Solenoids

The solenoid valve is mounted in the transmission valve housing.

The valve controls the pressure used for the torque converter clutch. The pressure is modulated so that full, partial or no engagement is achieved.

The control module activates the valve by pulsing it with B+ (300 Hz PWM). The valve is powered from control module pin 9 in the connector that makes contact directly with the transmission on the bottom of the control module. The valve is grounded from pin 4. The current varies between 0-1000 mA. The solenoid is normally closed and the hydraulic pressure rises as the current increases.

Scheme 59

The sensor is mounted inside the valve housing in the front part of the transmission and measures the speed of the transmission input shaft. This value is used by TCM to calculate the actual gearchange time and to regulate lock up. The Hall sensor measures a toothed wheel with 36 teeth.

The sensor is powered from TCM pin 12 and is grounded through pin 13.

Output Shaft Speed Sensor

The sensor is mounted inside the valve housing in the rear part of the transmission and measures the transmission output shaft speed. This value is used by TCM mainly to determine the gearchange points. The hall sensor measures a toothed wheel with 56 teeth.

The sensor is powered from TCM pin 19 and is grounded through pin 20.

Transmission Oil Temperature Sensor

The temperature sensor is mounted in the transmission valve housing and informs the control module about the current temperature. The value is used to correct the PWM ratio to the solenoids so that the gear changes are not affected by the viscosity of the oil. It is also used to activate the special gearchange program in case of overheating.

Scheme 60

The sensor comprises an NTC resistor built into a plastic casing. The NTC resistor characteristic means that the resistance drops as the temperature rises. The NTC resistor is supplied with 5V through a pull up from control module pin 8 and is grounded through pin 7.

Scheme 61

The TCM is mounted directly on top of the transmission. The selector lever is integrated in the control module. The TCM is mounted so that the selector lever shaft goes through the control module. The selector lever position is calibrated with a scan tool, there is no mechanical adjustment.

An exterior 16-pin connector connects to the car's electrical system. Underneath the control module is another connector (22-pin) that connects directly to the transmission. The TCM makes contact with all the transmission solenoids and sensors here.

Note. Magnetic fields from e.g. magnets and from high-current cables, such as starter cables and cables to auxiliary equipment, can interfere with the gear position sensor. A rule of thumb is max 1A per mm in distance from the control module. A starter cable carrying a current of 200A must therefore be kept at least 20 cm away from the control module.

The TCM has a microprocessor with clock, RAM memory and a programmable ROM. An internal bus connects the processor and memory with the I/O unit. The I/O unit reads values from the A/D converter for analogue inputs, digital inputs and bus, as well as activates the transistors' output stages.

Adaptive values are saved in a non-volatile memory (ROM). When changing transmission, these values must be zeroed using scan tool. After changing TCM they will be zeroed automatically after adding the control module using the scan tool.

The normally open solenoid valve is mounted in the transmission valve housing and is used by TCM when activating C2. The pressure to SLC2 is then raised from system pressure to D-pressure. The valve is also used to apply pressure to brake B2 for engine braking in 1st gear.

The control module activates the valve by applying B+ to it. The valve is powered from control module pin 5 in the connector in direct contact with the transmission on the bottom of the control module. The valve is grounded in the valve housing.

The normally closed solenoid valve is mounted in the transmission valve housing and is used together with S1 to apply pressure to brake B2 for engine braking in 1st gear.

The control module activates the valve by applying B+ to it. The valve is powered from control module pin 2 in the connector in direct contact with the transmission on the bottom of the control module. The valve is grounded in the valve housing.

The PWM controlled solenoid valve is mounted in the transmission valve housing and controls the pressure in brake B1. The valve is active in gear positions P, R, N, D (gears 1, 3, 4 and 5).

The control module activates the valve by pulsing it with B+ (300 Hz PWM). The valve is powered from control module pin 21 in the connector that makes contact directly with the transmission on the bottom of the control module. The valve is grounded from pin 16. The current varies between 0-1000mA. The solenoid is normally open and the hydraulic pressure drops as the current increases.

The PWM controlled solenoid valve is mounted in the transmission valve housing and controls the pressure in clutch C1. The valve is active in gear positions P, R, N, D (gears 5 and 6).

The control module activates the valve by pulsing it with B+ (300 Hz PWM). The valve is powered from control module pin 11 in the connector that makes contact directly with the transmission on the bottom of the control module. The valve is grounded from pin 10. The current varies between 0-1000 mA. The solenoid is normally open and the hydraulic pressure drops as the current increases.

The PWM controlled solenoid valve is mounted in the transmission valve housing and controls the pressure in clutch C2. The valve is active in gear positions P, R, N, D (gears 1, 2 and 3).

The control module activates the valve by pulsing it with B+ (300 Hz PWM). The valve is powered from control module pin 17 in the connector that makes contact directly with the transmission on the bottom of the control module. The valve is grounded from pin 18. The current varies between 0-1000mA. The solenoid is normally open and the hydraulic pressure drops as the current increases.

The PWM controlled solenoid valve is mounted in the transmission valve housing and controls the pressure in clutch C3. The valve is active in gear positions P, N, D (gears 1, 2, 4 and 6).

The control module activates the valve by pulsing it with B+ (300 Hz PWM). The valve is powered from control module pin 14 in the connector that makes contact directly with the transmission on the bottom of the control module. The valve is grounded from pin 22. The current varies between 0-1000mA. The solenoid is normally open and the hydraulic pressure drops as the current increases.

The PWM controlled solenoid valve is mounted in the transmission valve housing and controls the transmission system pressure. The value is controlled so that it is not higher than what is currently needed for any friction element. Brake B2 does not have its own pressure control valve and is therefore supplied by SLT.

The control module activates the valve by pulsing it with B+ (300 Hz PWM). The valve is powered from control module pin 3 in the connector that makes contact directly with the transmission on the bottom of the control module. The valve is grounded from pin 1. The current varies between 0-1000mA. The solenoid is normally open and the hydraulic pressure drops as the current increases.

The solenoid valve is mounted in the transmission valve housing.

The valve controls the pressure used for the torque converter clutch. The pressure is modulated so that full, partial or no engagement is achieved.

The control module activates the valve by pulsing it with B+ (300 Hz PWM). The valve is powered from control module pin 9 in the connector that makes contact directly with the transmission on the bottom of the control module. The valve is grounded from pin 4. The current varies between 0-1000mA. The solenoid is normally closed and the hydraulic pressure rises as the current increases.

Input Shaft Speed Sensor

The sensor is mounted inside the valve housing in the front part of the transmission and measures the speed of the transmission input shaft. This value is used by TCM to calculate the actual gearchange time and to regulate lock up. The Hall sensor measures a toothed wheel with 36 teeth.

The sensor is powered from TCM pin 12 and is grounded through pin 13.

The sensor is mounted inside the valve housing in the rear part of the transmission and measures the transmission output shaft speed. This value is used by TCM mainly to determine the gearchange points. The hall sensor measures a toothed wheel with 56 teeth.

The sensor is powered from TCM pin 19 and is grounded through pin 20.

The temperature sensor is mounted in the transmission valve housing and informs the control module about the current temperature. The value is used to correct the PWM ratio to the solenoids so that the gear changes are not affected by the viscosity of the oil. It is also used to activate the special gearchange program in case of overheating.

The sensor comprises an NTC resistor built into a plastic casing. The NTC resistor characteristic means that the resistance drops as the temperature rises. The NTC resistor is supplied with 5V through a pull up from control module pin 8 and is grounded through pin 7.

Scheme 62

The AF 40-6 automatic transmission (1) is an electronic 6-speed automatic transmission with lock-up. The transmission is mounted directly against the engine and has a final drive with integrated differential. The power unit is transverse mounted with front-wheel drive. Gear positions P-R-N-D are selected with the selector lever mounted in the centre console. Manual up/downshifting is possible.

Transmission functions can be divided into three parts

1. Mechanical
2. Hydraulic
3. Control system

Mechanical

1. Torque converter with lock-up clutch
2. 2 planetary gear units, of which the rear is double
3. 3 disc clutches
4. 1 band type brake
5. 1 multi-disc brake
6. 1 free wheel
7. Final drive with differential

The torque converter is bolted to the engine flywheel (flexplate). The converter is filled with oil via pressure from the automatic transmission oil pump. This is itself a hydraulic transmission that amplifies the engine torque the more it slips. The greatest torque amplification is obtained when the engine stalls (car stationary and full throttle in Drive), as the engine torque is at a maximum while the transmission input shaft is stationary. There will not be any amplification if the engine speed is the same as the transmission input shaft speed.

The torque converter clutch (lock up) is activated at a steady speed when there is no need for torque amplification. The difference in speed between the engine and the transmission does give an amplification of torque even at steady speeds but also entails heat loss. These losses result in unnecessary fuel consumption.

Note. The car must not be stalled (car held with brakes and full throttle in D position) for longer than 5 seconds.

Scheme 63

The transmission has 2 planetary gear units; front and rear. The front one is a single planetary gear and the rear one is double. The rear unit is Ravigneaux type with two planet gears between the rear sun gear and the only ring gear, which is the transmission output shaft. The two planet gears are fitted on a common planet carrier.

The front planetary gear sun gear is fixed and the power from the torque converter enters via its ring gear. This entails a reduction of the planet carrier speed used for gear 1-5 and R. The power from the planet carrier is conveyed to the rear planetary gear unit via clutches C1 and C3.

The rear planetary gear unit receives power either directly from the torque converter via clutch C2 or from the front planetary gear via clutches C1 and C3. The 2 brakes, B1 and B2, are used to hold firm the components in the rear planetary gear unit. B2 is combined with a free wheel (F1).

The activation of one or more friction elements results in a gear ratio. Brakes and clutches are activated hydraulically using solenoids controlled by the transmission control module (TCM).

The table shows the active elements for each of the gears.

Scheme 64

Gear changing performance is controlled by the applied element. When changing gear, it is not possible to apply more than one friction element for consistent behavior. In the same way, it is not possible to release more than one friction element when changing gear. This means it is not possible to change from one gear to an optional gear. The following shows the normal gear changing sequence from standstill

In this sequence you can clearly see that no more than 1 element is released or applied at one time. If you suddenly release the accelerator in 3rd gear after accelerating at full throttle, it is logical to change up to 6th gear.

Changing directly from 3 to 6, however, is not suitable because C1 and C3 must then be released and C2 and B1 applied. Changing 3 to 5 and 5 to 6 must be done instead. The need of these intermediate changes is especially noticeable during kickdown at various speeds. The permitted changing sequences are determined by a program in TCM.

The transmission is blocked mechanically in selector lever position P.

Hydraulic

A special automatic transmission fluid must be used. The transmission does not have an oil dipstick. The drain plug has an extra, central plug for checking the level that is connected to a pipe that reaches up to the correct level in the box. Fill the oil through the conventional filler plug until the level is correct and oil runs out of the level hole.

The temperature of the oil is important when checking the level. The temperature can be read with a scan tool.

All the friction elements are applied hydraulically. The hydraulic pressure is generated by a pump driven by the engine. The pump is mounted in the transmission behind the torque converter. The drive is direct from the torque converter.

Oil passes to the valve housing where the manual valve is integrated. The valve is affected by the gear selector wire, which in turn is operated by the selector lever. The valve has 3 positions, P/N, R and D/M. In position P/N, the oil will drain directly back to the transmission sump. In position R, the oil will pass directly to brake B2, which is used for reverse gear. In position D/M, oil will pass to the circuits used for the forward gears.

To control the flow of oil to and from the friction elements, 6 stepless (linear) solenoids are used. With them, TCM can regulate the pressure precisely. Each solenoid is connected to a mechanical control valve. They work as variable relay valves and are needed to control the relatively high flow of oil that is required. The solenoids do not possess the flow capacity needed to feed the oil directly to each friction element.

The table below shows the linear solenoids and their task.

There are also 2 on/off-type solenoids. The following table shows these digital solenoids and their duties.

Scheme 65

The automatic transmission (2) has an oil cooler integrated in the engine radiator (1) and constitutes one unit together with the transmission. Fluid is circulated by the transmission fluid pump and carried via hydraulic hoses (3) to the radiator and back to the transmission.

Scheme 66

General

The transmission is electronically controlled by a control unit (TCM, Transmission Control Module). The TCM (1) is mounted directly on top of the transmission (2) and has one connector to the car's electrical system and one to the transmission. The gear position sensor is Hall type and integrated in the control module. The TCM is mounted so that the selector lever shaft goes through the control module. The gear lever sensor position is calibrated in position N with a scan tool, there is no mechanical adjustment. TCM controls the solenoids to maintain or change gear. The solenoids are controlled with PWM (Pulse Width Modulation) to achieve a variable flow of oil.

Shifting

The determining factors for changing gear are two values; current gear and target gear. Current gear is the one engaged at the moment and the target gear is the one TCM wants to change to. As long as these to values are the same there will be no gear change. Gear changing is initiated only when the target gear differs from the current gear. It is mainly the vehicle speed and acceleration that determines the target gear in automatic transmissions. The vehicle speed is taken from a special sensor, output speed, while the acceleration is taken from the engine management system (ECM) via the high speed bus.

Gear changing must also follow a permitted schedule. If a direct change to the target gear is not present in the schedule, there will be an intermediate gear change. If, for example, the car is in 5th gear and the accelerator suddenly indicates a target gear of 2 (kickdown), the gear change will be 5 to 3 and 3 to 2. This is because 5 to 2 is not a valid gear change (refer to the service information Mechanical for more information on this).

When a gear change is carried out, TCM will calculate a requested pressure for each solenoid circuit. The pressure is converted to a requested current that later results in a PWM ratio. The requested pressure is modulated according to a predetermined procedure so that the gear change is made comfortable without unnecessary wear. Current engine torque taken from ECM via the high speed bus is used for this purpose. A higher pressure is required for higher engine torque.

TCM reads the resulting current to each solenoid and can finely adjust the PWM ratio so that the requested pressure (current) agrees with the actual current. The transmission does not have a pressure sensor so current pressure cannot be sent back to the control system. For this reason, the solenoids are calibrated very precisely.

Manual gear changing can be accomplished with the selector lever in position D using the up/down switch in the lever. A manual gear change must be fully completed before TCM will accept a new change command. The current gear is shown in DIC. The highest permitted gear for pulling away is 3rd. For safety's sake, there will be a change down from gear 6, 5 and 4 automatically after kickdown and engine speed below 2000 rpm.

TCM sends continuous information on the high speed bus concerning the engine torque allowed by the transmission. When changing gear this value drops and ECM limits engine torque if it exceeds this value.

Lock Up

The torque converter clutch is activated at steady speed in gears 3-6 when there is no need for any torque amplification. The slipping in procedure is regulated by comparing the speed on the input shaft with the engine speed obtained from ECM via the high speed bus. Lock up will not work at temperatures below 15°C. If the brake is depressed or acceleration increases, the function will be activated.

Safety Features

A reverse detent function prevents reverse gear being engaged if the car is travelling faster than 7 km/h when the selector lever is moved from N to R. Overrevving in gear position M will be prevented by not allowing changing down to take place if the speed is too high.

Special Gear Change Program

For high engine loads without a corresponding increase in speed one of two hill-climbing programs will be chosen. Gear changing is done at higher engine speeds and the gear will remain engaged for longer periods until the extra load ceases. These gearchange programs are used to avoid changing up and down unnecessarily, e.g. when driving up long inclines with trailer and to avoid overheating the transmission oil. The Sport Mode can be engaged by a switch. Upon detecting the sport mode request TCM adapts the shift lines in order to enable a more progressive driving. Special gear change programs are not activated at speeds above 150 km/h. If a special gear change program is active when the speed increases to over 150 km/h, the program will continue, however, until the load has normalized.

Diagnostics

The control module has diagnosis for internal faults. The solenoids are diagnosed with respect to open circuits and short circuits. They are also pulsed and the inductive voltage peak is analyzed to make sure the coil is not partially shorted. The speed sensor and temperature sensor circuits and plausibility are checked. High speed bus communication is checked to make sure no necessary messages are missing. Mechanical faults (slipping or wrong gear) are detected by comparing speed sensor values with the engaged gear.

Limp Home

If the power supply to TCM or to the solenoids is cut, the car can still be driven. Gear position D/M will give 2nd gear and P-R-N will work as normal but the gear will be engaged roughly as there is no regulation.

In case of a major fault in the transmission, mechanical or electrical, TCM will cut the supply to the solenoids in a controlled manner. In most cases, the control module will attempt to maintain the current gear until the car has stopped. Subsequently, the control module will attempt to engage 2nd gear if D/M is selected. After this, the supply to the solenoids will be cut and the transmission will lose all electrical control.

If an invalid gear ratio or the wrong gear is detected, the engine torque will be limited to 170 N.m in reverse and 150 N.m forward. For other faults, the torque will be limited to higher values depending on failure.

Scheme 67

The AF 40-6 automatic transmission (1) is an electronic 6-speed automatic transmission with lock-up. The transmission is mounted directly against the engine and has a final drive with integrated differential. The power unit is transverse mounted with front-wheel drive. Gear positions P-R-N-D are selected with the selector lever mounted in the centre console. Manual up/downshifting is possible.

Transmission functions can be divided into three parts

1. Mechanical
2. Hydraulic
3. Control system

1. Torque converter with lock-up clutch
2. 2 planetary gear units, of which the rear is double
3. 3 disc clutches
4. 1 band type brake
5. 1 multi-disc brake
6. 1 free wheel
7. Final drive with differential

Torque Converter Components

Note. The car must not be stalled (car held with brakes and full throttle in D position) for longer than 5 seconds.

The torque converter is bolted to the engine flywheel (flexplate). The converter is filled with oil via pressure from the automatic transmission oil pump. This is itself a hydraulic transmission that amplifies the engine torque the more it slips. The greatest torque amplification is obtained when the engine stalls (car stationary and full throttle in Drive), as the engine torque is at a maximum while the transmission input shaft is stationary. There will not be any amplification if the engine speed is the same as the transmission input shaft speed.

The torque converter clutch (lock up) is activated at a steady speed when there is no need for torque amplification. The difference in speed between the engine and the transmission does give an amplification of torque even at steady speeds but also entails heat loss. These losses result in unnecessary fuel consumption.

Overview Transmission

The transmission has 2 planetary gear units; front and rear. The front one is a single planetary gear and the rear one is double. The rear unit is Ravigneaux type with two planet gears between the rear sun gear and the only ring gear, which is the transmission output shaft. The two planet gears are fitted on a common planet carrier.

The front planetary gear sun gear is fixed and the power from the torque converter enters via its ring gear. This entails a reduction of the planet carrier speed used for gear 1-5 and R. The power from the planet carrier is conveyed to the rear planetary gear unit via clutches C1 and C3.

The rear planetary gear unit receives power either directly from the torque converter via clutch C2 or from the front planetary gear via clutches C1 and C3. The 2 brakes, B1 and B2, are used to hold firm the components in the rear planetary gear unit. B2 is combined with a free wheel (F1).

The activation of one or more friction elements results in a gear ratio. Brakes and clutches are activated hydraulically using solenoids controlled by the transmission control module (transmission control module (TCM)).

The table shows the active elements for each of the gears.

Operation of Clutches and Brakes - ERROR - Title exists for titlesource=no-title

Overview Clutches and Brakes

Operation of Front and Rear Planetary Gear Units

Gear changing performance is controlled by the applied element. When changing gear, it is not possible to apply more than one friction element for consistent behavior. In the same way, it is not possible to release more than one friction element when changing gear. This means it is not possible to change from one gear to an optional gear. The following shows the normal gear changing sequence from standstill

Normal Gear Change Operation

In this sequence you can clearly see that no more than 1 element is released or applied at one time. If you suddenly release the accelerator in 3rd gear after accelerating at full throttle, it is logical to change up to 6th gear.

Changing directly from 3 to 6, however, is not suitable because C1 and C3 must then be released and C2 and B1 applied. Changing 3 to 5 and 5 to 6 must be done instead. The need of these intermediate changes is especially noticeable during kickdown at various speeds. The permitted changing sequences are determined by a program in transmission control module (TCM).

The transmission is blocked mechanically in selector lever position P.

Hydraulic Components

A special automatic transmission fluid must be used. The transmission does not have an oil dipstick. The drain plug has an extra, central plug for checking the level that is connected to a pipe that reaches up to the correct level in the box. Fill the oil through the conventional filler plug until the level is correct and oil runs out of the level hole.

The temperature of the oil is important when checking the level. The temperature can be read with a scan tool.

All the friction elements are applied hydraulically. The hydraulic pressure is generated by a pump driven by the engine. The pump is mounted in the transmission behind the torque converter. The drive is direct from the torque converter.

Oil passes to the valve housing where the manual valve is integrated. The valve is affected by the gear selector wire, which in turn is operated by the selector lever. The valve has 3 positions, P/N, R and D/M. In position P/N, the oil will drain directly back to the transmission sump. In position R, the oil will pass directly to brake B2, which is used for reverse gear. In position D/M, oil will pass to the circuits used for the forward gears.

To control the flow of oil to and from the friction elements, 6 stepless (linear) solenoids are used. With them, transmission control module (TCM) can regulate the pressure precisely. Each solenoid is activated by the transmission control module transmission control module (TCM) logic to control directly each friction element.

The table below shows the linear solenoids and their task.

SLB1, SLC1, SLC2, and SLC3 Solenoids - ERROR - Title exists for titlesource=no-title

SLT and SLU Solenoids

There are also 2 on/off-type solenoids. The following table shows these digital solenoids and their duties.

S1 and S2 Solenoids

Cooling System

The automatic transmission (2) has an oil cooler integrated in the engine radiator (1) and constitutes one unit together with the transmission. Fluid is circulated by the transmission fluid pump and carried via hydraulic hoses (3) to the radiator and back to the transmission.

General

The transmission is electronically controlled by a control unit (transmission control module (TCM), Transmission Control Module). The transmission control module (TCM) (1) is mounted directly on top of the transmission (2) and has one connector to the car's electrical system and one to the transmission. The gear position sensor is Hall type and integrated in the control module. The transmission control module (TCM) is mounted so that the selector lever shaft goes through the control module. The gear lever sensor position is calibrated in position N with a scan tool, there is no mechanical adjustment. transmission control module (TCM) controls the solenoids to maintain or change gear. The solenoids are controlled with PWM (Pulse Width Modulation) to achieve a variable flow of oil.

Shifting

The determining factors for changing gear are two values; current gear and target gear. Current gear is the one engaged at the moment and the target gear is the one transmission control module (TCM) wants to change to. As long as these to values are the same there will be no gear change. Gear changing is initiated only when the target gear differs from the current gear. It is mainly the vehicle speed and acceleration that determines the target gear in automatic transmissions. The vehicle speed is taken from a special sensor, output speed, while the acceleration is taken from the engine management system (ECM) via the high speed bus.

Gear changing must also follow a permitted schedule. If a direct change to the target gear is not present in the schedule, there will be an intermediate gear change. If, for example, the car is in 5th gear and the accelerator suddenly indicates a target gear of 2 (kickdown), the gear change will be 5 to 3 and 3 to 2. This is because 5 to 2 is not a valid gear change (refer to the service information Mechanical for more information on this).

When a gear change is carried out, transmission control module (TCM) will calculate a requested pressure for each solenoid circuit. The pressure is converted to a requested current that later results in a PWM ratio. The requested pressure is modulated according to a predetermined procedure so that the gear change is made comfortable without unnecessary wear. Current engine torque taken from ECM via the high speed bus is used for this purpose. A higher pressure is required for higher engine torque.

transmission control module (TCM) reads the resulting current to each solenoid and can finely adjust the PWM ratio so that the requested pressure (current) agrees with the actual current. The transmission does not have a pressure sensor so current pressure cannot be sent back to the control system. For this reason, the solenoids are calibrated very precisely.

Manual gear changing can be accomplished with the selector lever in position D using the up/down switch in the lever. A manual gear change must be fully completed before transmission control module (TCM) will accept a new change command. The current gear is shown in DIC. The highest permitted gear for pulling away is 3rd. For safety's sake, there will be a change down from gear 6, 5 and 4 automatically after kickdown and engine speed below 2000 rpm.

transmission control module (TCM) sends continuous information on the high speed bus concerning the engine torque allowed by the transmission. When changing gear this value drops and ECM limits engine torque if it exceeds this value.

Lock Up

The torque converter clutch is activated at steady speed in gears 3-6 when there is no need for any torque amplification. The slipping in procedure is regulated by comparing the speed on the input shaft with the engine speed obtained from ECM via the high speed bus. Lock up will not work at temperatures below 15°C. If the brake is depressed or acceleration increases, the function will be activated.

Safety Features

A reverse detent function prevents reverse gear being engaged if the car is travelling faster than 7 km/h when the selector lever is moved from N to R. Overrevving in gear position M will be prevented by not allowing changing down to take place if the speed is too high.

Special Gear Change Program

For high engine loads without a corresponding increase in speed one of two hill-climbing programs will be chosen. Gear changing is done at higher engine speeds and the gear will remain engaged for longer periods until the extra load ceases. These gearchange programs are used to avoid changing up and down unnecessarily, e.g. when driving up long inclines with trailer and to avoid overheating the transmission oil. The Sport Mode can be engaged by a switch. Upon detecting the sport mode request transmission control module (TCM) adapts the shift lines in order to enable a more progressive driving. Special gear change programs are not activated at speeds above 150 km/h. If a special gear change program is active when the speed increases to over 150 km/h, the program will continue, however, until the load has normalized.

Diagnostics

The control module has diagnosis for internal faults. The solenoids are diagnosed with respect to open circuits and short circuits. They are also pulsed and the inductive voltage peak is analyzed to make sure the coil is not partially shorted. The speed sensor and temperature sensor circuits and plausibility are checked. High speed bus communication is checked to make sure no necessary messages are missing. Mechanical faults (slipping or wrong gear) are detected by comparing speed sensor values with the engaged gear.

Limp Home

If the power supply to transmission control module (TCM) or to the solenoids is cut, the car can still be driven. Gear position D/M will give 2nd gear and P-R-N will work as normal but the gear will be engaged roughly as there is no regulation.

In case of a major fault in the transmission, mechanical or electrical, transmission control module (TCM) will cut the supply to the solenoids in a controlled manner. In most cases, the control module will attempt to maintain the current gear until the car has stopped. Subsequently, the control module will attempt to engage 2nd gear if D/M is selected. After this, the supply to the solenoids will be cut and the transmission will lose all electrical control.

If an invalid gear ratio or the wrong gear is detected, the engine torque will be limited to 170 N.m in reverse and 150 N.m forward. For other faults, the torque will be limited to higher values depending on failure.

Illustration Tool Number/Description DT-498-B GE-498-B KM-498-B CH-48027 J-21867-A Pressure Measuring Equipment DT-519 KM-519 Oil Seal/Ring Installer DT-674-A KM-674-A J-29077 Installer DT-6328 KM-6328 Adapter DT-6329 KM-6329 J-21867-50 Adapter DT-41623-B KM-J-41623-B J-41623-B 8792806 Disconnect Tool DT-45096 J-45096 TransFlow Cooler Flush Machine DT-45096-30 J-45096-30 TransFlow Adapter EN-328-B KM-328-B J-6125-1B Pin Remover EN-469-A KM-469-A J-23129 Remover/Installer J-41239-1A Seal Installer J-45000 Seal Remover J-45201 Seal Remover

Scheme 68

Scheme 69

Scheme 70

Scheme 71

Scheme 72

Scheme 73

Scheme 74

See also:
• Testing for Intermittent Conditions and Poor Connections
• Lifting and Jacking the Vehicle
• Fastener Caution
• Control Module References
• Symptoms - Vibration Diagnosis and Correction
• Front Floor Console Replacement
• Battery Tray Replacement
• Front Wheelhouse Front Liner Replacement
• Tire and Wheel Removal and Installation
• Special Tools
• Front Wheel Drive Shaft Replacement - Left Side (GNA)
• Engine Support Fixture
• Exhaust Front Pipe Replacement (LHU)
• Indicator/Warning Message Description and Operation
• Transmission General Description
• Transmission Component and System Description
• Transmission Fluid Level and Condition Check
• Automatic Transmission Fluid Leaks
• Fluid Leak Diagnosis
• Noise and Vibration Analysis
• Road Test
• Symptoms - Automatic Transmission
• Range Selector Lever Cable Adjustment
• Adhesives, Fluids, Lubricants, and Sealers
• Transmission Replacement