Automatic Transmission, VT25-E (Troubleshooting): Other Saturn VUE I

Tools Required

J 45195 Pressure Gage

1. Remove the fluid pressure test hole plug from the transaxle.
2. Install the J 45195 .
3. Ensure that the gear selector is in PARK and the parking brake is set.
4. Install a scan tool.
5. Start the engine and allow the engine to warm up at idle.
6. Access the Line PC Solenoid functional test on the scan tool output controls.
7. With the engine speed at idle, use the scan tool to increase the Line PC Solenoid amperage to 1 amp. Read and record the corresponding line pressure on the pressure gage.
8. Slowly increase the engine speed to 1,400-1,500 RPM before performing the next test step.
9. Using the scan tool, decrease the Line PC Solenoid amperage to 0.2 amp. Read and record the corresponding line pressure on the pressure gage.
10. Compare the collected readings to the Line Pressure table. Refer to «Line Pressure»(ref-188804-S16655942942005090200000) .
11. If pressure readings differ greatly from the table, refer to «Low Line Pressure»(ref-188833-S21910024472005090200000) or «High Line Pressure»(ref-188833-S19177230802005090200000) .
12. Shut the engine OFF. Remove the J 45195 .
13. Install the fluid pressure test hole plug. Tighten: Tighten the plug to 9 N.m (7 lb ft).

Electrical/Garage Shift Procedure

Perform a preliminary test before the road test in order to ensure that the electronic control inputs are operating properly. If you do not check the inputs before operating the transmission, you could misdiagnose a simple electrical condition as a major transmission condition.

A scan tool provides valuable information and must be used on the VT25-E transaxle for accurate diagnosis.

1. Ensure that the gear selector is in PARK (P) and set the parking brake.
2. Install the scan tool.
3. Start the engine.
4. Using the scan tool, the Transmission Scan Tool Data Definitions and the Transmission Scan Tool Data List, verify that the data parameters listed are present and functioning properly. Refer to «Scan Tool Data Definitions»(ref-188805-S03492120982005090200000) and «Scan Tool Data List»(ref-188805-S22953402622005090200000) .

Poor Acceleration at Low Speed

If the stator is freewheeling at all times, the vehicle tends to have poor acceleration from a standstill. At speeds above 50-55 km/h (30-35 mph), the vehicle may act normal. For poor acceleration, you should first determine that the exhaust system is not blocked, and the transmission ratio is accurate for the throttle angle and the output speed.

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.

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 conditions 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. Plug wires Look in each end. If there is red dust, ozone, or a black substance - carbon - present, then the wires are bad. Also look for a white discoloration of the wire. This indicates arcing during hard acceleration.
3. Coil Look for a black discoloration on the bottom of the coil. This indicates arcing while the engine is misfiring.
4. Fuel injector The filter may be plugged.
5. 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.
6. EGR valve The valve may let in too much or too little unburnable exhaust gas and could cause the engine to run rich or lean.
7. MAP sensor Like a vacuum leak, the engine will not get the correct amount of fuel for proper engine operation.
8. Carbon on the intake valves Carbon restricts the proper flow of air/fuel mixture into the cylinders.
9. Flat cam Valves do not open enough to let the proper fuel/air mixture into the cylinders.
10. Oxygen sensor This sensor may command the engine too rich or too lean for too long.
11. Fuel pressure This may be too low.
12. Engine mounts Vibration of the mounts can be multiplied by TCC engagement.
13. Axle joints Check for vibration.
14. TP Sensor 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.
15. Cylinder balance Bad piston rings or poorly sealing valves can cause low power in a cylinder.
16. Fuel contamination This causes poor engine performance.

Composition Side of Clutch Plates

Dry the plates and inspect the plates for the following conditions

1. Pitting
2. Flaking
3. Wear
4. Glazing
5. Cracking
6. Charring
7. Chips or metal particles embedded in the lining

Replace a composition plate which shows any of these conditions.

Steel Side of Clutch Plates

Wipe the plates dry and check the plates for heat discoloration. If the surfaces are smooth, even if color smear is indicated, you can reuse the plate. If the plate is discolored with heat spots or if the surface is scuffed, replace the plate.

Causes of Burned Clutch Plates

The following conditions can result in a burned clutch plate

1. Incorrect usage of clutch or apply plates
2. Engine coolant or water in the transmission fluid
3. A cracked clutch piston
4. Damaged or missing seals
5. Low line pressure
6. Valve body conditions The valve body face is not flat. Porosity is between channels. The valve bushing clips are improperly installed. The checkballs are misplaced.
7. The Teflon® seal rings are worn or damaged.

Engine Coolant/Water in Transmission

Note. The antifreeze or water will deteriorate the seals, gaskets and the glue that bonds the clutch material to the pressure plate. Both conditions may cause damage to the transmission.

If antifreeze or water has entered the transmission, perform the following

1. Disassemble the transmission.
2. Replace all of the rubber type seals (the coolant will attack the seal material which will cause leakage).
3. Replace the composition-faced clutch plate assemblies (the facing material may separate from the steel center portion).
4. Replace all of the nylon parts (washers).
5. Replace the torque converter.
6. Thoroughly clean and rebuild the transmission, using new gaskets and oil filter.
7. Flush the cooler lines after the transmission cooler has been properly repaired or replaced.

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 powder, such as foot 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's instructions in order to determine the amount of dye to use.
2. Detect the leak with the black light.
3. 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 seal bore
4. Damaged or worn seal
5. Improper installation
6. Cracks in component
7. Manual or output shaft surface is scratched, nicked, or damaged
8. Loose or worn bearing causing excess seal wear

Case Porosity Repair

Some external leaks are caused by case porosity in non-pressurized areas. You can usually repair these leaks with the transmission in the vehicle.

1. Thoroughly clean the area to be repaired with a cleaning solvent. Air dry the area.
2. Using instructions from the manufacturer, mix a sufficient amount of an epoxy to make the repair.
3. While the transmission case is still hot, apply the epoxy. You can use a clean, dry soldering acid brush to clean the area and also to apply the epoxy cement. Make certain that the area to be repaired is fully covered.
4. Allow the epoxy cement to cure for three hours before starting the engine.
5. Repeat the fluid leak diagnosis procedures.

Transmission Overheats

Transmission Overheats

Line Pressure Instability

Line Pressure Instability

Low Line Pressure

Low Line Pressure

High Line Pressure

High Line Pressure

Noisy in Reverse Only

Noisy in Reverse Only

No Drive in Forward Ranges

No Drive in Forward Ranges

Slips in Drive

Slips in Drive

No Reverse

No Reverse

Slips in Reverse

Slips in Reverse

No Forward and Reverse

No Forward and Reverse

No Low or Reverse

No Low or Reverse

No Park

No Park

Transmission Does Not Shift Out of Park

Transmission Does Not Shift Out of Park

Stays in Drive

Stays in Drive

Stays in Low

Stays in Low

Stays in Intermediate

Stays in Intermediate

Stays in Reverse

Stays in Reverse

Range Selector Displays Incorrect Range

Range Selector Displays Incorrect Range

Harsh Garage Shift

Harsh Garage Shift

Poor Driveability - Poor or No Ratio Control

Poor Driveability - Poor or No Ratio Control