Symptoms - Automatic Transmission
| Diagnostic Category | Diagnostic Information |
|---|---|
| The following table consists of eight diagnostic categories that are located in the left-hand column. Using this column, choose the appropriate category based on the operating conditions of the vehicle or transmission. After selecting a category, use the right-hand column to locate the specific symptom diagnostic information. | |
| Fluid Diagnosis: This category contains the following topics: Fluid condition - appearance, contaminants, smell, overheating Line pressure - high or low Fluid leaks | Refer to Transmission Fluid Checking Procedure . Refer to Fluid Foaming . Refer to Transmission Overheats . Refer to Transmission Overheats at WOT . Refer to High Line Pressure . Refer to Low Line Pressure . Refer to Inadequate Lubrication at Low Line or Heavy Loads . Refer to Inadequate Lubrication . Refer to Fluid Leak Diagnosis . Refer to Case Extension Bearing/Seal Failed . Refer to Oil Out the Vent Tube . Refer to Automatic Transmission Fluid Leaks . |
| Noise and Vibration Diagnosis: This category contains the following topics: Noise - drive gear, final drive, whine, growl, rattle, buzz, popping Vibration | Refer to Noise . Refer to Vibration . Refer to Flexplate/Torque Converter Vibration Test . |
| Range Performance Diagnosis: This category contains the following topics: Drives in Neutral No Park/Neutral No Reverse Engine stalling No Drive No engine braking No or incorrect gear selection Shift selector indicator does not match transmission gear range | Refer to Forward Motion in Neutral . Refer to No Park . Refer to No Reverse . Refer to Engine Stall . Refer to No Torque in Reverse and Third . Refer to Loss of Power . Refer to No Torque in Second Gear . Refer to Loss of Drive . Refer to No Overrun Braking - D1 . Refer to No Engine Braking - D1 . Refer to No Overrun Braking - D2 . Refer to No Engine Braking - D2 . Refer to No Second Gear Engine Braking - D2 . Refer to No Overrun Braking - D3 . Refer to No Engine Braking - D3 . Refer to Engine Starts in Gear . Refer to Shift Lever Indicates Wrong Gear . Refer to No Gear Selection . Refer to Remains in Park . Refer to Difficult to Shift Out of Park . Refer to Does Not Stay in Park . Refer to Range Selector Displays Incorrect Range . |
| Shift Quality - Feel - Diagnosis: This category contains the following topics: Erratic shifts Harsh, soft, delayed or slipping shifts Harsh, soft, or delayed engagement | Refer to Erratic Shift Quality . Refer to Harsh Shifts . Refer to Transmission Slips . Refer to Harsh Shift 3 to 4 . Refer to Harsh Shift 4 to 3 . Refer to Harsh Shift D4 to D3, D2, or D1 . Refer to Soft Shifts . Refer to Delayed Shift 1 to 2 . Refer to Soft Shift 2 to 3 . Refer to Soft Shift D3 to D2 . Refer to Soft Shift 3 to 2 . Refer to No D3 to D2 . Refer to No D2 to D1 . Refer to Harsh Shift D to R . Refer to Soft Shift into R . Refer to Soft Shift R to D . |
| Shift Pattern: This category contains the following topics: One forward gear missing or slipping One forward gear only Two forward gears only Non-First gear start | Refer to No First Gear - D1 . Refer to No First Gear - D2 . Refer to No First Gear - D4 . Refer to No Second Gear - D1 . Refer to No Second Gear - D2 . Refer to No Second Gear - D4 . Refer to No Second Gear - D3 . Refer to No Third Gear - D3 . Refer to No Third Gear - D4 . Refer to No Fourth Gear - D4 . Refer to First Gear Only - D4 . Refer to Second Gear Only - D4 . Refer to First and Second Gear Only - D4 . Refer to First and Fourth Gear Only - D4 . Refer to Second and Third Gear Only - D4 . Refer to Third and Fourth Gear Only - D4 . Refer to Second Gear Starts . Refer to Third Gear Starts . Refer to Fourth Gear Starts . |
| Shift Speed Diagnosis: This category contains the following topic: Inaccurate or inconsistent shift points | Refer to Inaccurate Shift Points . |
| Torque Converter Diagnosis: This category contains the following topics: Torque Converter Diagnosis TCC does not apply TCC does not release TCC apply/release quality Poor acceleration/No torque multiplication Converter Ballooning Engine Stall | Refer to Torque Converter Diagnosis Procedure . Refer to Flexplate/Torque Converter Vibration Test . Refer to No Torque Converter Clutch (TCC) Apply . Refer to Torque Converter Clutch (TCC) Stuck On . Refer to Soft Torque Converter Clutch (TCC) Apply . Refer to Incorrect Torque Converter Clutch (TCC) Apply or Release . Refer to No Torque Multiplication . Refer to Torque Converter Clutch (TCC) Slipping . Refer to Converter Ballooning . Refer to Engine Stall in Neutral . |
| Symptom not found or no symptom detected | Refer to Transmission Fluid Checking Procedure . Refer to Road Test Procedure . Refer to Line Pressure Check Procedure . |
Symptoms - Automatic Transmission
Scheme 177
Circuit Description
The transmission range (TR) switch is part of the park/neutral position (PNP) and back-up lamp switch assembly, which is externally mounted on the transmission manual shaft. The TR switch contains four internal switches that indicate the transmission gear range selector lever position. The PCM supplies ignition voltage to each switch circuit. As the gear range selector lever is moved, the state of each switch may change, causing the circuit to open or close. An open circuit or switch indicates a high voltage signal. A closed circuit or switch indicates a low voltage signal. The PCM detects the selected gear range by deciphering the combination of the voltage signals. The PCM compares the actual voltage combination of the switch signals to a TR switch combination chart stored in memory.
Diagnostic Aids
Refer to Transmission Range Switch Logic for valid combinations of switch signal circuits A, B, C and Parity. On the table, HI indicates an ignition voltage signal. LOW indicates a zero voltage signal.
Test Description
The numbers below refer to the step numbers on the diagnostic table.
- 4: By disconnecting the TR switch, the ground path of all TR switch circuits would be removed and the PCM should recognize all circuits as open. The scan tool should display HI for all range signal states.
- 6: This step tests the TR switch wiring for an open or the lack of the signal voltage from the PCM.
- 7: This step tests the TR switch wiring and the PCM by providing a ground path through a fused jumper wire. When grounded, the scan tool range signal states should change to LOW.
- 8: This step tests the TR switch wiring and the PCM by providing a ground path through a fused jumper wire. When grounded, the scan tool range signal states should change to LOW.
- 9: This step tests the TR switch wiring and the PCM by providing a ground path through a fused jumper wire. When grounded, the scan tool range signal states should change to LOW.
- 10: This step tests the TR switch wiring and the PCM by providing a ground path through a fused jumper wire. When grounded, the scan tool range signal states should change to LOW.
| Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
| 1 | Install a scan tool. Turn ON the ignition, with the engine OFF. Select the TR Sw. on the scan tool. With the scan tool, observe the TR Sw. display while selecting each transmission range: P, R, N, D4, D3, D2 and D1. Does each selected transmission range match the scan tool TR Sw. display? | Go to Step 2 | Go to Step 3 | |
| 2 | Observe the IPC gear range display while selecting each transmission range: P, R, N, D4, D3, D2, D1. Does each selected transmission range match the IPC display? | Go to Intermittent Conditions in Engine Controls - 4.8L, 5.3L, and 6.0L | Go to Step 13 | |
| 3 | With the scan tool, observe the TR Sw. A/B/C/P display. Does the scan tool TR Sw. A/B/C/P parameter indicate HI for all range signal states? | Go to Step 15 | Go to Step 4 | |
| 4 | Turn OFF the ignition. Disconnect the TR switch connector. Turn ON the ignition, with the engine OFF. Does the scan tool TR Sw. A/B/C/P parameter indicate HI for all range signal states? | Go to Step 6 | Go to Step 5 | |
| 5 | Disconnect the IPC connector. Refer to Instrument Panel Cluster (IPC) Replacement in Instrument Panel, Gages and Console. Did the affected circuit display HI? | Go to Step 18 | Go to Step 6 | |
| 6 | Using the DMM and the J 35616 GM Terminal Test Kit, measure the voltage from terminal 5 of the TR switch connector to ground. Measure the voltage from terminal 6 of the TR switch connector to ground. Measure the voltage from terminal 8 of the TR switch connector to ground. Measure the voltage from terminal 4 of the TR switch connector to ground. Does the voltage measure within the specified value at all four terminals? | 10-12 V | Go to Step 7 | Go to Step 12 |
| 7 | Connect a fused jumper wire from terminal 5 of the TR switch connector, signal circuit A, to ground while monitoring the scan tool TR Sw. A/B/C/P parameter. When signal circuit A is grounded, do any other signal circuits indicate LOW? | Go to Step 14 | Go to Step 8 | |
| 8 | Connect a fused jumper wire from terminal 4 of the TR switch connector, signal circuit B, to ground while monitoring the scan tool TR Sw. A/B/C/P parameter. When signal circuit B is grounded, do any other signal circuits indicate LOW? | Go to Step 14 | Go to Step 9 | |
| 9 | Connect a fused jumper wire from terminal 6 of the TR switch connector, signal circuit C, to ground while monitoring the scan tool TR Sw. A/B/C/P parameter. When signal circuit C is grounded, do any other signal circuits indicate LOW? | Go to Step 14 | Go to Step 10 | |
| 10 | Connect a fused jumper wire from terminal 8 of the TR switch connector, signal circuit P, to ground while monitoring the scan tool TR Sw. A/B/C/P parameter. When signal circuit P is grounded, do any other signal circuits indicate LOW? | Go to Step 14 | Go to Step 13 | |
| 11 | Test the signal circuits of the TR switch that did not indicate HI for a short to ground. Refer to Testing for Short to Ground and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 19 | Go to Step 17 | |
| 12 | Test the signal circuits of the TR switch and the PCM that did not indicate proper voltage for an open. Refer to Testing for Continuity and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 19 | Go to Step 17 | |
| 13 | Test the signal circuits of the TR switch between the PCM and the IPC for an open. Refer to Testing for Continuity and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 19 | Go to Step 18 | |
| 14 | Test the affected signal circuits of the TR switch for a shorted together condition. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 19 | Go to Step 16 | |
| 15 | Test the ground circuit of the TR switch for an open. Refer to Testing for Continuity and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 19 | Go to Step 16 | |
| 16 | Replace the TR switch. The TR switch is part of the park/neutral position switch. Refer to Park/Neutral Position Switch Replacement . Did you complete the replacement? | Go to Step 19 | ||
| 17 | Replace the PCM. Refer to Powertrain Control Module (PCM) Replacement in Engine Controls - 4.8L, 5.3L, and 6.0L. Did you complete the replacement? | Go to Step 19 | ||
| 18 | Replace the IPC. Refer to Instrument Panel Cluster (IPC) Replacement in Instrument Panel, Gages and Console. Did you complete the replacement? | Go to Step 19 | ||
| 19 | Turn ON the ignition, with the engine OFF. With the scan tool, observe the TR Sw. display while selecting each transmission range: P, R, N, D4, D3, D2 and D1. Does each selected transmission range match the scan tool TR Sw. display? | System OK | Go to Step 2 |
Range Selector Displays Incorrect Range
Scheme 178
Tow/haul mode enables the operator to achieve enhanced shift performance when towing or hauling a load. When tow/haul mode is selected, the tow/haul switch input signal to the body control module (BCM) is momentarily toggled to zero volts. This signals the powertrain control module (PCM) to extend the length of time between upshifts and increase transmission line pressure. Cycling the tow/haul switch again disables tow/haul mode and returns the transmission to a normal shift pattern.
If the electrical circuit checks are OK and the tow/haul shift pattern is not occurring, there may be a mechanical/hydraulic condition that prevents tow/haul operation. Refer to Symptoms - Automatic Transmission .
The numbers below refer to the step numbers on the diagnostic table.
- 2: This step tests for a faulty tow/haul switch.
- 3: This step tests for voltage input from the BCM to the tow/haul switch.
- 6: This step tests for ground integrity.
| Step | Action | Yes | No |
|---|---|---|---|
| 1 | Install a scan tool. Turn ON the ignition, with the engine OFF. Cycle the tow/haul switch while observing Tow/Haul Mode on the scan tool. Does the scan tool display Active when the switch is first pressed, and then Inactive when the switch is pressed again? | Go to Intermittent Conditions in Engine Controls - 4.8L, 5.3L, and 6.0L | Go to Step 2 |
| 2 | Remove the connector from the tow/haul switch. Using the J 35616 GM Terminal Test Kit, install a fused jumper wire from terminal D to terminal A of the tow/haul switch connector. Does the scan tool Tow/Haul Mode indicate a status change? | Go to Step 7 | Go to Step 3 |
| 3 | Using the DMM and the J 35616 , measure the voltage at terminal D of the tow/haul switch connector. Is ignition voltage measured? | Go to Step 6 | Go to Step 4 |
| 4 | Using the DMM and the J 35616 , measure the voltage at terminal C3-B11 of the body control module (BCM). Is ignition voltage measured? | Go to Step 5 | Go to Step 8 |
| 5 | Test the Tow/Haul switch signal circuit of the tow/haul switch for an open or shorted condition. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 9 | Go to Intermittent Conditions in Engine Controls - 4.8L, 5.3L, and 6.0L |
| 6 | Test the ground circuit of the tow/haul switch for an open or shorted condition. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 9 | Go to Intermittent Conditions in Engine Controls - 4.8L, 5.3L, and 6.0L |
| 7 | Replace the tow/haul switch. Refer to Trim Plate Bezel Replacement - Instrument Panel (I/P) Cluster in Instrument Panel, Gages, and Console. Did you complete the replacement? | Go to Step 9 | |
| 8 | Test the BCM for proper operation. Refer to Diagnostic Starting Point - Body Control System in Body Control System. Did you find and correct the condition? | Go to Step 9 | |
| 9 | After the repair is complete, observe Tow/Haul Mode on the scan tool display, while cycling the tow/haul switch. Does the scan tool display Active when the switch is first pressed, and then Inactive when the switch is pressed again? | System OK | Go to Step 1 |
Tow/Haul Switch/Indicator Always On or Inoperative
Transmission Fluid Checking Procedure
- Start the engine and operate the vehicle for 15 minutes or until the transmission fluid reaches an operating temperature of 82-93° C (180-200° F).
- Park the vehicle on a level surface.
- With your foot on the brake, move the shift lever through each gear range. Pause for about three seconds in each range, ending in Park.
- Apply the parking brake and let the engine idle for 3 minutes.
- Remove the transmission fluid level indicator. Wipe the indicator clean. Insert the indicator. Give the indicator a full twist in order to close.
- Wait 3 seconds and remove the indicator.
- Read both sides of the indicator. The fluid must be within the hot cross-hatched area using the lowest level reading.
| Step | Action | Yes | No |
|---|---|---|---|
| DEFINITION: Diagnose transmission fluid conditions by color. | |||
| 1 | Check the fluid color. Is the fluid color red? | Go to Step 2 | Go to Step 11 |
| 2 | Is the fluid level satisfactory? | System OK | Go to Step 3 |
| 3 | Check the fluid. Is the fluid foamy? | Go to Step 8 | Go to Step 4 |
| 4 | Check the fluid level. The proper fluid level should be in the middle of the X-hatch. Is the fluid level high? | Go to Step 9 | Go to Step 5 |
| 5 | The fluid will be low. Add fluid to the proper fluid level. Is the fluid level satisfactory? | Go to Step 6 | |
| 6 | Check for external leaks. Refer to Fluid Leak Diagnosis . Were any leaks found? | Go to Step 7 | Go to Step 20 |
| 7 | Correct the leak condition. Was the leak condition corrected? | Go to Step 20 | |
| 8 | Is the fluid level too high? | Go to Step 9 | Go to Step 10 |
| 9 | Remove excess fluid to the proper fluid level. Refer to Automatic Transmission Fluid/Filter Replacement . Is the fluid level satisfactory? | Go to Step 20 | |
| 10 | Check for contaminants in the fluid. Drain the fluid to determine the source of the contamination. Was the fluid drained? | Go to Step 15 | |
| 11 | Is the fluid color non-transparent pink? | Go to Step 12 | Go to Step 13 |
| 12 | Replace the cooler. Is the replacement complete? | Go to Step 15 | |
| 13 | IMPORTANT: Transmission fluid may turn dark with normal use. This does not always indicate oxidation or contamination. The fluid color should be light brown.Is the fluid color light brown? | Go to Step 14 | |
| 14 | IMPORTANT: A very small amount of material in the bottom pan is a normal condition, but large pieces of metal or other material in the bottom pan require a transmission overhaul. Drain the fluid to determine if the fluid is contaminated.Is the fluid contaminated? | Go to Step 15 | Go to Step 18 |
| 15 | Perform root cause and repair as necessary. Is the repair complete? | Go to Step 16 | |
| 16 | Clear TRANS ADAPT. Are the reset procedures complete? | Go to Step 17 | |
| 17 | Add new fluid. Is the procedure complete? | Go to Step 20 | |
| 18 | Change the fluid and the filter. Refer to Automatic Transmission Fluid/Filter Replacement . Is this procedure complete? | Go to Step 19 | |
| 19 | Are the reset procedures complete? | Go to Step 20 | |
| 20 | Is the fluid level satisfactory? | System OK | Go to Step 1 |
| IMPORTANT |
|---|
| Transmission fluid may turn dark with normal use. This does not always indicate oxidation or contamination. |
| IMPORTANT |
|---|
| A very small amount of material in the bottom pan is a normal condition, but large pieces of metal or other material in the bottom pan require a transmission overhaul. |
Transmission Fluid Checking Procedure
Scheme 179
Tools Required
J 21867 Pressure Gage
Line pressures are calibrated for two sets of gear ranges-Drive-Park-Neutral, and Reverse. This allows the transmission line pressure to be appropriate for different pressure needs in different gear ranges
| Gear Range | Line Pressure Range |
|---|---|
| Drive, Park, or Neutral | 35-171 psi |
| Reverse | 67-324 psi |
Line Pressure Check Procedure
Before performing a line pressure check, verify that the pressure control solenoid for the transmission is receiving the correct electrical signal from the vehicle computer
- Install a scan tool.
- Start the engine and set the parking brake.
- Check for diagnostic trouble codes, including the diagnostic code for a pressure control solenoid.
- Repair the vehicle if necessary. Include the following areas: Inspect the fluid level. Inspect the manual linkage at the transmission. Install or connect the scan tool. Install or connect the J 21867 at the line pressure tap.
- Put the gear selector in PARK and set the parking brake.
- Start the engine and allow the engine to warm up at idle.
- Access the Override Pressure Control Solenoid test on the scan tool.
- Increase the Pressure Control Solenoid Current in 0.1 amp increments. Read the corresponding line pressure on the J 21867 . Allow the pressure to stabilize for 5 seconds after each current change.
- Compare your data to the Drive-Park-Neutral «Line Pressure»(/chevrolet/chevy-express-g1500/1996-2012/remont/automatic-trans/#automatic-transmission-4l80-e4l85-e-introduction-service-replacement__line-pressure) .
- Remove the J 21867 .
- Install the line pressure tap plug.
If your pressure readings differ greatly from the line pressure table, refer to the Diagnostic Tables.
The scan tool is only able to control the pressure control solenoid in PARK and NEUTRAL with the vehicle stopped at idle. This protects the clutches from extremely high or low pressures in DRIVE or REVERSE ranges.
Road Test Procedure
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
- Electrical Function Check
- Upshift Control and Torque Converter Clutch (TCC) Apply
- Part Throttle Detent Downshifts
- Full Throttle Detent Downshifts
- Manual Downshifts
- Coasting Downshifts
- Manual Gear Range Selection REVERSE Manual FIRST Manual SECOND Manual THIRD
| IMPORTANT | Complete the test in the sequence given. Incomplete testing cannot guarantee an accurate evaluation. |
Before the road test, ensure the following
- The engine is performing properly.
- Transmission fluid level is correct.
- Tire pressure is correct.
During the road test
- Perform the test only when traffic conditions permit.
- Operate the vehicle in a controlled, safe manner.
- Observe all traffic regulations.
- View the scan tool data while conducting this test. Take along qualified help in order to operate the vehicle safely.
- Observe any unusual sounds or smells.
After the road test, check the following
- Transmission fluid level. Refer to «Transmission Fluid Checking Procedure»(/chevrolet/chevy-express-g1500/1996-2012/remont/automatic-trans/#automatic-transmission-4l80-e4l85-e-troubleshooting__transmission-fluid-checking-procedure) .
- Diagnostic Trouble Codes (DTCs) that may have set during the testing. Refer to the applicable DTC.
- Scan tool data for any abnormal readings or data.
Electrical Function Check
Perform this check first, in order to ensure the electronic transmission components are connected and functioning properly. If these components are not checked, a simple electrical condition could be mis-diagnosed.
- Connect the scan tool.
- Ensure the gear selector is in PARK and set the parking brake.
- Start the engine.
- Verify that the following scan tool data can be obtained and is functioning properly. Refer to «Scan Tool Data List»(/chevrolet/chevy-express-g1500/1996-2012/remont/automatic-trans/#automatic-transmission-4l80-e4l85-e-diagnostic-information-procedures__scan-tool-data-list) for typical data values. Data that is questionable may indicate a concern. Engine speed Transmission input speed, turbine Transmission output speed Vehicle speed TFP manual valve position switch Transmission range, engine list 4WD low Commanded gear PC solenoid reference current PC solenoid actual current PC solenoid duty cycle Brake switch Engine coolant temperature Transmission fluid temperature Throttle angle Ignition voltage 1-2 shift solenoid 2-3 shift solenoid TCC solenoid duty cycle TCC slip speed
- Monitor the brake switch signal while depressing and releasing the brake pedal. The scan tool should display: Closed when the brake pedal is released Open when the brake pedal is depressed
- 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 2-3 seconds in each gear position. Verify the gear engagements are immediate and not harsh.
- Monitor transmission range on the scan tool, engine list. Apply the brake pedal and ensure the parking brake is set. Move the gear selector through all ranges. Pause 2-3 seconds in each range. Return gear selector to PARK. Verify that all selector positions match the scan tool display.
- Check throttle angle input. Apply the brake pedal and ensure the parking brake is set. Ensure the gear selector is in PARK. Monitor throttle angle while increasing and decreasing engine speed with the throttle pedal. The scan tool throttle angle 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.
Upshift Control and Torque Converter Clutch (TCC) Apply
The PCM calculates the upshift points based primarily on two inputs: throttle angle and vehicle speed. When the PCM determines that conditions are met for a shift to occur, the PCM commands the shift by closing or opening the ground circuit for the appropriate solenoid.
Perform the following steps
- Refer to «Shift Speed»(/chevrolet/chevy-express-g1500/1996-2012/remont/automatic-trans/#automatic-transmission-4l80-e4l85-e-introduction-service-replacement__shift-speed) and choose a throttle position of 10 percent, 25 percent or 50 percent. All throttle angles shown should be tested to cover the normal driving range.
- Monitor the following scan tool parameters: Throttle angle Vehicle speed Engine speed Output shaft speed Commanded gear Slip speed Solenoid states
- Place the gear selector in the OVERDRIVE position.
- Accelerate the vehicle using the chosen throttle angle. Hold the throttle steady.
- As the transmission upshifts, note the vehicle speed when the shift occurs for each gear change. There should be a noticeable shift feel or engine speed change within 1-2 seconds of the commanded gear change.
- Compare the shift speeds to the Shift Speed table. Refer to «Shift Speed»(/chevrolet/chevy-express-g1500/1996-2012/remont/automatic-trans/#automatic-transmission-4l80-e4l85-e-introduction-service-replacement__shift-speed) . Shift speeds may vary slightly due to transmission fluid temperature or hydraulic delays in responding to electronic controls. Note any harsh, soft or delayed shifts or slipping. Note any noise or vibration.
- Repeat steps 1-6 to complete all throttle angles.
- Check for TCC apply in THIRD and FOURTH gear. Typical apply speeds in FOURTH gear range from 72-88 km/h (45-55 mph) depending on engine size, engine type and axle ratio. Note the TCC apply point. When the TCC applies there should be a noticeable drop in engine speed and a drop in slip speed to below 100 RPM. If the TCC apply can not be detected: Check for DTCs. Refer to «Torque Converter Diagnosis Procedure»(/chevrolet/chevy-express-g1500/1996-2012/remont/automatic-trans/#automatic-transmission-4l80-e4l85-e-troubleshooting__torque-converter-diagnosis-procedure) . Lightly tap and release the brake pedal. The TCC will release.
Part Throttle Detent Downshift
- Place the gear selector in the OVERDRIVE position.
- Accelerate the vehicle to 64-88 km/h (40-55 mph) in FOURTH gear.
- Quickly increase throttle angle to greater than 50 percent.
- Verify the following: The TCC releases The transmission downshifts immediately to THIRD gear
Full Throttle Detent Downshift
- Place the gear selector in the OVERDRIVE position.
- Accelerate the vehicle to speeds of 64-88 km/h (40-55 mph) in FOURTH gear.
- Quickly increase throttle angle to 100 percent (WOT).
- Verify the following: The TCC releases The transmission downshifts immediately to SECOND gear
Manual Downshifts
The shift solenoid valves do not control manual downshifts. All manual downshifts are hydraulic. The solenoid states will change during, or shortly after, a manual downshift is selected.
Manual 4-3 Downshift
- Place the gear selector in the OVERDRIVE position.
- Accelerate the vehicle to 64-88 km/h (40-55 mph) in FOURTH gear.
- Release the throttle while moving the gear selector to THIRD.
- Verify the following: The transmission downshifts immediately to THIRD gear The engine slows the vehicle
Manual 4-2 Downshift
- Place the gear selector in the OVERDRIVE position.
- Accelerate the vehicle to 64-72 km/h (40-45 mph).
- Release the throttle while moving the gear selector to SECOND.
- Verify the following: The TCC releases The transmission downshifts immediately to SECOND gear The engine slows the vehicle
Manual 4-1 Downshift
- Place the gear selector in the OVERDRIVE position.
- Accelerate the vehicle to 64 km/h (40 mph).
- Release the throttle while moving the gear selector to FIRST.
- Verify the following: The TCC releases The transmission immediately downshifts to FIRST Gear. The engine slows the vehicle.
Coasting Downshifts
- Place the gear selector in the OVERDRIVE position.
- Accelerate the vehicle to FOURTH gear with the TCC applied.
- Release the throttle and lightly apply the brakes.
- Verify the following: The TCC releases Downshifts occur at speeds shown in the Shift Speed table. Refer to «Shift Speed»(/chevrolet/chevy-express-g1500/1996-2012/remont/automatic-trans/#automatic-transmission-4l80-e4l85-e-introduction-service-replacement__shift-speed) .
Manual Gear Range Selection
The shift solenoids control the upshifts in the manual gear ranges.
Perform the following tests using 10 percent to 15 percent throttle angle.
Reverse
- With the vehicle stopped, move the gear selector to REVERSE.
- Slowly accelerate the vehicle.
- Verify that there is no noticeable slip, noise or vibration.
Manual First
- With the vehicle stopped, move the gear selector to FIRST.
- Accelerate the vehicle to 32 km/h (20 mph).
- Verify the following: No upshifts occur. The TCC does not apply. There is no noticeable slip, noise, or vibration.
Manual Second
- With the vehicle stopped, move the gear selector to SECOND.
- Accelerate the vehicle to 57 km/h (35 mph).
- Verify the following: The 1-2 shift occurs. The 2-3 shift does not occur. There is no noticeable slip, noise, or vibration.
Manual Third
- With the vehicle stopped, move the gear selector to THIRD.
- Accelerate the vehicle to 64 km/h (40 mph).
- Verify the following: The 1-2 shift occurs. The 2-3 shift occurs. There is no noticeable slip, noise, or vibration.
Torque Converter Diagnosis Procedure
The torque converter clutch (TCC) is applied by fluid pressure, which is controlled by a 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.
- The stator assembly freewheels in both directions.
- The stator assembly remains locked up at all times.
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 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 vehicle 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 inspect 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.
Whine Noise
| IMPORTANT | 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
- Place your foot on the brake.
- Put the gear selector in DRIVE.
- Depress the accelerator to approximately 1,200 RPM for no more than six 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
- Something is not allowing the clutch to become fully engaged.
- Something is not allowing the clutch to release.
- The clutch is releasing and applying at the same time.
One of the following conditions may be causing the condition to occur
- Leaking turbine shaft seals
- A restricted release orifice
- A distorted clutch or housing surface due to long converter bolts
- Defective friction material on the TCC plate
If Shudder Occurs After TCC has Applied
| IMPORTANT | 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.
- Spark plugs Inspect for cracks, high resistance or a broken insulator.
- Plug wires Look in each end. If there is red dust, ozone, or a black substance, carbon, present, the wires are bad. Also look for a white discoloration of the wire. This indicates arcing during hard acceleration.
- Coil Look for a black discoloration on the bottom of the coil. This indicates arcing while the engine is misfiring.
- Fuel injector The filter may be plugged.
- 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.
- 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.
- MAP/MAF sensor Like a vacuum leak, the engine will not get the correct amount of fuel for proper engine operation.
- Carbon on the intake valves Carbon restricts the proper flow of air/fuel mixture into the cylinders.
- Flat cam Valves do not open enough to let the proper fuel/air mixture into the cylinders.
- Oxygen sensor This sensor may command the engine too rich or too lean for too long.
- Fuel pressure This may be too low.
- Engine mounts Vibration of the mounts can be multiplied by TCC engagement.
- Axle joints Check for vibration.
- 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.
- Cylinder balance Bad piston rings or poorly sealing valves can cause low power in a cylinder.
- Fuel contamination This causes poor engine performance.
Torque Converter Evaluation and Diagnosis
Replace the torque converter if any of the following conditions exist
- External leaks appear in the hub weld area.
- The converter hub is scored or damaged.
- The converter pilot is broken, damaged, or fits poorly into the crankshaft.
- You discover steel particles after flushing the cooler and the cooler lines.
- The pump is damaged, or you discover steel particles in the converter.
- 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.
- The converter has an imbalance which cannot be corrected. Refer to «Flexplate/Torque Converter Vibration Test»(/chevrolet/chevy-express-g1500/1996-2012/remont/automatic-trans/#automatic-transmission-4l80-e4l85-e-troubleshooting) .
- The converter is contaminated with engine coolant which contains antifreeze.
- An internal failure occurs in the stator roller clutch.
- You notice excessive end play.
- Overheating produces heavy debris in the clutch.
- 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
- The oil has an odor or the oil is discolored, even though metal or clutch facing particles are not present.
- The threads in one or more of the converter bolt holds are damaged. Correct the condition with a new thread insert.
- 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.
- 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.
Isolating Vibration
Note. Some engine/transaxle combinations cannot be balanced in this manner due to restricted access or limited clearances between the torque converter bolts and the engine. Ensure that the bolts do not bottom out in the lug nuts or the torque converter cover could be dented and cause internal damage.
To isolate and correct a flywheel or torque converter vibration, separate the torque converter from the flywheel to determine if vibration is in the engine or transmission.
- With the engine at idle speed and the transmission in PARK or NEUTRAL, observe the vibration.
- Turn the engine OFF.
- Raise and suitably support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/chevy-express-g1500/1996-2012/remont/hoistjack/#general-information__lifting-and-jacking-the-vehicle) in General Information.
- Remove the transmission converter cover bolts and the cover.
- Mark the relationship of the converter to the flywheel.
- Remove the bolts attaching the converter to the flywheel.
- Slide the torque converter away from the flywheel.
- Rotate the flywheel and torque converter to inspect for defects or missing balance weights. Refer to «Engine Flywheel Cleaning and Inspection»(/chevrolet/chevy-express-g1500/1996-2012/remont/mechanical/#engine-mechanical-removal-installation-2-of-3-48l-53l-60l__engine-flywheel-cleaning-and-inspection) in Engine Mechanical - 4.8L, 5.3L, and 6.0L.
- Lower the vehicle.
- With the engine at idle speed and the transmission in PARK or NEUTRAL, observe the vibration. Refer to «Diagnostic Starting Point - Vibration Diagnosis and Correction»(/chevrolet/chevy-express-g1500/1996-2012/remont/oem-general-information/#vibration-symptoms-diagnosis-and-correction__diagnostic-starting-point-vibration-diagnosis) in Vibration Diagnosis and Correction.
- Turn the engine OFF.
Indexing Torque Converter
To determine and correct a torque converter vibration, the following procedure may have to be performed several times to achieve the best possible torque converter to flywheel balance.
- Raise and suitably support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/chevy-express-g1500/1996-2012/remont/hoistjack/#general-information__lifting-and-jacking-the-vehicle) in General Information.
- Rotate the torque converter one bolt position.
- Align the torque converter hub (2) in the engine crankshaft (3) and install the torque converter to flywheel bolts.
- Lower the vehicle.
- With the engine at idle speed and the transmission in PARK or NEUTRAL, observe the vibration. Refer to «Noise and Vibration Analysis»(/chevrolet/chevy-express-g1500/1996-2012/remont/automatic-trans/#automatic-transmission-4l60-e4l65-e-troubleshooting__noise-and-vibration-analysis) . Repeat this procedure until you obtain the best possible balance.
- Install the transmission converter cover bolts and the cover.
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.
If noise or vibration is noticeable in PARK and NEUTRAL with the engine at idle, but is less noticeable as RPM increases, the cause may be from poor engine performance.
- Vibration may also be caused by a small amount of water inside the converter.
- Inspect the tires for the following conditions: Uneven wear Imbalance Mixed sizes Mixed radial and bias ply
- Inspect the suspension components for the following conditions: Alignment and wear Loose fasteners Driveline damage or wear
- Inspect the engine and transmission mounts for damage and loose bolts.
- Inspect the transmission case mounting holes for the following conditions: Missing bolts, nuts, and studs Stripped threads Cracks
- Inspect the flywheel for the following conditions: Missing or loose bolts Cracks Imbalance
- Inspect the torque converter for the following conditions: Missing or loose bolts or lugs Missing or loose balance weights Imbalance caused by heat distortion or fluid contamination
Composition Plates
Dry the plates and inspect the plates for the following conditions
- Pitting
- Flaking
- Delamination - splitting or separation of bonded clutch material
- Wear
- Glazing
- Cracking
- Charring
- Chips or metal particles embedded in the lining
Replace a composition plate which shows any of these conditions.
Steel 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
- Incorrect usage of clutch or apply plates
- Engine coolant or water in the transmission fluid
- A cracked clutch piston
- Damaged or missing seals
- Low line pressure
- 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.
- 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
- Disassemble the transmission.
- Replace all of the rubber type seals. The coolant will attack the seal material which will cause leakage.
- Replace the composition-faced clutch plate assemblies. The facing material may separate from the steel center portion.
- Replace all of the nylon parts - washers.
- Replace the torque converter.
- Thoroughly clean and rebuild the transmission, using new gaskets and oil filter.
- Flush the cooler lines after the transmission cooler has been properly repaired or replaced.
General Method
- Verify that the leak is transmission fluid.
- Thoroughly clean the suspected leak area.
- Operate the vehicle for 24 km (15 mi), or until normal operating temperatures are reached.
- Park the vehicle over clean paper or cardboard.
- Shut OFF the engine.
- Look for fluid spots on the paper.
- Make the necessary repairs.
Powder Method
- Thoroughly clean the suspected leak area with solvent.
- Apply an aerosol type powder, such as foot powder, to the suspected leak area.
- Operate the vehicle for 24 km (15 mi), or until normal operating temperatures are reached.
- Shut OFF the engine.
- Inspect the suspected leak area.
- Trace the leak path through the powder in order to find the source of the leak.
- Make the necessary repairs.
Dye and Black Light Method
A fluid dye and black light kit is available from various tool manufacturers.
- Follow the manufacturer's instructions in order to determine the amount of dye to use.
- Detect the leak with the black light.
- 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
- Fluid level/pressure is too high
- Plugged vent or drain-back holes
- Improperly tightened fasteners
- Dirty or damaged threads
- Warped flanges or sealing surface
- Scratches, burrs, or other damage to the sealing surface
- Damaged or worn gasket
- Cracking or porosity of the component
- Improper sealant used, where applicable
- Incorrect gasket
Seals
- Fluid level/pressure is too high
- Plugged vent or drain-back holes
- Damaged seal bore
- Damaged or worn seal
- Improper installation
- Cracks in component
- Manual or output shaft surface is scratched, nicked, or damaged
- Loose or worn bearing causing excess seal wear
Possible Points of Fluid Leaks
Transmission Oil Pan
- Incorrectly tightened oil pan bolts
- Improperly installed or damaged oil pan gasket
- Damaged oil pan or mounting face
- Incorrect oil pan gasket
Case Leak
- Damaged or missing fill tube seal
- Mislocated fill tube bracket
- Damaged vehicle speed sensor seal
- Damaged manual shaft seal
- Loose or damaged oil cooler connector fittings
- Worn or damaged propeller shaft oil seal
- Loose line pressure pipe plug
- Porous casting warped torque converter housing
Leak at the Torque Converter End
- Converter leak in the weld area
- Converter seal lip cut. Check the converter hub for damage
- Converter seal bushing moved forward and damaged
- Converter seal garter spring missing from the seal
- Porous casting of the transmission case or the oil pump
Leak at the Vent Pipe or the Fluid Fill Tube
- Overfilled system
- Water or coolant in the fluid. The fluid will appear milky
- Transmission case porous
- Incorrect fluid level indicator
- Plugged vent
- Drain-back holes plugged
- Mispositioned oil pump to case gasket, if equipped
Scheme 180
| Callout | Component Name |
|---|---|
| 3 | Bolt and Seal Assembly, A/Trans O/Pump |
| 5 | Seal, A/Trans Oil Pump |
| 8 | Connector, Transmission Oil Cooler Pipe |
| 9 | Pipe, Vent |
| 15 | Seal, Case Extension |
| 20 | Seal Asm., Prop Shaft Front Slip Yoke Oil |
| 22 | Sensor Assembly, A/T Input Speed and 2WD Output Speed (4WD Plug) |
| 24 | Plug, Line Pressure Test Hole |
| 27 | Bolt, Oil Pan |
| 29 | Seal, Transmission Oil Pan |
| 34 | Harness Assembly, A/Trans Wiring |
| 201 | Seal Asm., Torque Converter Oil |
| 707 | Seal, Manual Shift Shaft |
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.
- Thoroughly clean the area to be repaired with a cleaning solvent. Air dry the area.
- Using instructions from the manufacturer, mix a sufficient amount of an epoxy to make the repair.
- 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.
- Allow the epoxy cement to cure for three hours before starting the engine.
- Repeat the fluid leak diagnosis procedures.
Shift Solenoid Leak Test
Tools Required
J 44246 Solenoid Testing Kit
- Remove the solenoid from the control valve body. Refer to «Valve Body and Pressure Switch Replacement»(/chevrolet/chevy-express-g1500/1996-2012/remont/automatic-trans/#automatic-transmission-4l80-e4l85-e-introduction-service-replacement__valve-body-and-pressure-switch-replacement) .
- Install the 1-2 shift solenoid valve or the 2-3 shift solenoid valve into bore number 1 of the J 44246 and install the factory bolt to retain the solenoid.
- Connect the solenoid testing harness supplied with the J 44246 to the solenoid.
- Apply compressed air to the J 44246 .
- Air should flow through the solenoid. If air does not flow through the solenoid, replace the solenoid. Refer to «Valve Body and Pressure Switch Replacement»(/chevrolet/chevy-express-g1500/1996-2012/remont/automatic-trans/#automatic-transmission-4l80-e4l85-e-introduction-service-replacement__valve-body-and-pressure-switch-replacement) .
- Connect the solenoid testing harness to the 12 volt positive and negative (-) battery terminals.
- Observe if the solenoid is operating electrically. An audible clicking noise can be heard when connecting or disconnecting power.
- Observe the air flow through the solenoid. The flow will completely or nearly completely stop. Replace the solenoid if there continues to be an obvious air leak when the solenoid is energized.
- Install the solenoid into the control valve body. Refer to «Valve Body and Pressure Switch Replacement»(/chevrolet/chevy-express-g1500/1996-2012/remont/automatic-trans/#automatic-transmission-4l80-e4l85-e-introduction-service-replacement__valve-body-and-pressure-switch-replacement) .
Automatic Transmission Oil Cooler Flushing and Flow Test (J 35944-A)
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 wear-out. 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.
| IMPORTANT | For FWD, use the J 35944-A transmission oil cooler and line flusher or equivalent to flush the transmission oil cooler and the oil cooler pipes whenever the transaxle is removed for the following repairs: Torque converter Oil pump Oil pump drive shaft Drive sprocket support Transaxle overhaul complete Transaxle assembly replacement |
| IMPORTANT | For RWD, use the J 35944-A or equivalent to flush the transmission oil cooler and the oil cooler pipes whenever the transmission is removed for the following repairs: Torque converter Oil pump Turbine shaft Transmission overhaul complete Transmission assembly replacement |
Only GM Goodwrench DEXRON®III automatic transmission fluid should be used when doing a repair on a GM transmission.
Time allowance for performing the cooler flow checking and flushing procedure has been included in the appropriate labor time guide operations since the 1987 model year. The service procedure steps for oil cooler flushing are as follows
Cooler Flow Check and Flushing Steps
- Tools Required
- Preparation
- Back Flush
- Forward Flush
- Flow Check
- Clean-up
Tools Required
- J 35944-A Transmission Oil Cooler and Line Flusher
- J 35944-22 Transmission Oil Cooler Flushing Fluid
- J 35944-200 Cooler Flushing Adapter
- Measuring cup
- Funnel
- Water supply - hot water recommended
- Water hose, at least 16 mm (5/8 in) ID
- Shop air supply with water/oil filters, regulator and pressure gage
- Air chuck with clip, if available
- Oil drain container
- Pail with lid - 19 L (5 gallon)
- Eye protection
- Rubber gloves
Preparation
- During the installation of the repaired or replacement transmission, do not connect the oil cooler pipes.
- Remove the fill cap (9) on the J 35944-A and fill the flusher tank (4) with 0.6 L (20-21 oz) of J 35944-22 , using the measuring cup (6). Do not overfill.
- Install the fill cap (9) on the J 35944-A and pressurize the flusher tank (4) to 550-700 kPa (80-100 psi), using the shop air supply at the tank air valve (2).
- With the water supply valve (1) on the J 35944-A in the OFF position, connect the water supply hose from the J 35944-A to the water supply at the faucet.
- Turn ON the water supply at the faucet.
Back Flush
- Inspect the transmission oil cooler pipes for kinks or damage. Repair as necessary.
- Connect the J 35944-A to the oil cooler feed front connector. Use the J 35944-200 , if required.
- Clip the discharge hose (2) onto the oil drain container.
- Attach the J 35944-A to the undercarriage of the vehicle with the hook provided and connect the flushing system feed supply hose (1) from the J 35944-A to the rear connector oil cooler return pipe. Use the J 35944-200 , if required.
- Turn the J 35944-A water supply valve (3) to the ON position and allow water to flow through the oil cooler and pipes for 10 seconds to remove any remaining transmission fluid. If water does not flow through the oil cooler and pipes, the cause of the blockage must be diagnosed and the plugged component must be repaired or replaced. Continue with the cooler flushing and flow check procedure once the blockage is corrected.
- Turn the J 35944-A water supply valve (3) to the OFF position and clip the discharge hose onto a 19 liter (5 gallon) pail with a lid, to avoid splashback.
- Turn the J 35944-A water supply valve (3) to the ON position and depress the trigger (1) to mix cooler flushing solution into the water flow. Use the clip provided on the handle to hold the trigger (1) down. The discharge will foam vigorously when the solution is introduced into the water stream.
- Flush the oil cooler and pipes with water and solution for 2 minutes. During this flush, attach the shop air supply 825 kPa (120 psi) to the flushing system feed air valve (2) located on the J 35944-A , for 3-5 seconds at the end of every 15-20 second interval to create a surging action.
- Release the trigger (1) and turn the J 35944-A water supply valve (3) to the OFF position.
Forward Flush
- Disconnect both hoses (1 and 2) from the oil cooler pipes and connect them to the opposite oil cooler pipe. This will allow the oil cooler and pipes to be flushed in the normal flow direction.
- Repeat Step 6 and 7 of the Back Flush.
- Release the trigger (1) of the J 35944-A and allow water only to rinse the oil cooler and pipes for 1 minute.
- Turn the J 35944-A water supply valve (3) to the OFF position and turn OFF the water supply at the faucet.
- Attach the shop air supply to the flushing system feed air valve (2) on the J 35944-A and blow out the water from the oil cooler and pipes. Continue, until no water comes out of the discharge hose.
Flow Test
- Disconnect the hose from the oil cooler pipe. Connect the oil cooler feed pipe, front connector, to the transmission for normal flow.
- Clip the discharge hose (1) to an empty oil container.
- Confirm the transmission is filled with automatic transmission fluid. Refer to «Fluid Capacity Specifications»(/chevrolet/chevy-express-g1500/1996-2012/remont/automatic-trans/#automatic-transmission-4l80-e4l85-e-introduction-service-replacement__fluid-capacity-specifications) for the correct automatic transmission fluid capacity.
- Start the engine with the transmission in PARK range and run for 30 seconds after fluid begins to flow from the discharge hose (1). A minimum of 1.9 L (2 qt) must be discharged during this 30 second run time.
- If the fluid flow meets or exceeds 1.9 L (2 qt) in 30 seconds, connect the oil cooler feed pipe to the front connector on the transmission.
- If fluid flow is less than 1.9 L (2 qt) in 30 seconds, perform the following diagnosis: Disconnect the J 35944-A discharge hose (1) from the oil cooler return pipe. Disconnect the oil cooler feed pipe at the radiator. Connect the J 35944-A discharge hose (1) to the oil cooler feed pipe, radiator end. Clip the discharge hose (1) onto the oil drain container. Start the engine with the transmission in PARK range and run for 30 seconds after fluid begins to flow from the discharge hose (1). A minimum of 1.9 L (2 qt) must be discharged during this 30 second run time.
- If the amount of transmission fluid flow remains less than 1.9 L (2 qt) in 30 seconds, inspect the oil cooler feed pipe, front connector, for restrictions or damage. If no condition is found with the feed pipe, front connector, inspect the transmission.
Clean-up
- Disconnect the water supply hose from the J 35944-A and bleed any remaining air pressure from the flusher tank.
- Remove the fill cap from the J 35944-A and return any unused flushing solution to its container. Rinse the J 35944-A with water. Do not store the J 35944-A with flushing solution in it.
- After every third use, clean the J 35944-A as described in the instructions included with the tool.
- Dispose of any waste water/solution and transmission fluid in accordance with local regulations.
Automatic Transmission Oil Cooler Flushing and Flow Test (J 45096)
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.
| IMPORTANT | Use the J 45096 transmission oil cooling system flush and flow test tool or equivalent to flush and flow test the transmission oil cooler and the oil cooler pipes after the transaxle is removed for repairs. |
Only GM Goodwrench DEXRON®III automatic transmission fluid should be used when doing a repair on a GM transmission.
Time allowance for performing the cooler flow checking and flushing procedure has been included in the appropriate labor time guide operations since the 1987 model year. The service procedure steps for oil cooler flushing and flow testing are as follows
Cooler Flow Check and Flushing Steps
- Machine Set-up
- Determine Minimum Flow Rate
- Back Flush
- Forward Flush
- Flow Test
- Code Recording Procedure
- Clean-up
Tools Required
- J 35944-200 Cooler Flushing Adapter
- J 45096 Transmission Oil Cooling System Flush and Flow Test Tool
- Shop air supply with water/oil filters, regulator and pressure gage - minimum 90 PSI (621 kPa)
- Eye protection
- Rubber gloves
Machine Set-up
- Verify that the main power switch (1) is in the OFF position.
- Place the main function switch (2) in the IDLE position.
- Connect J 45096 to the vehicle 12 V 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.
- Turn the main power switch to the ON position.
- Fill the supply tank with DEXRON®III/Mercon®, or equivalent, through the fill port.
- Install and tighten the fill cap.
- Connect a shop air supply hose to the quick-disconnect on the rear panel marked SUPPLY AIR.
Determine Minimum Flow Rate
- From the machine display, identify the temperature of the automatic transmission fluid that is stored in the supply vessel of J 45096 .
- Determine whether the transmission oil cooler is steel or aluminum by using a magnet (1) at the cooler flange (2) at the radiator.
- 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 GPM 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.
- Inspect the 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.
| Temperature Range | Steel | Aluminum |
|---|---|---|
| 18-19° C (65-66° F) | 0.6 gpm | 0.5 gpm |
| 19-21° C (67-70° F) | 0.7 gpm | 0.6 gpm |
| 22-24° C (71-75° F) | 0.8 gpm | 0.7 gpm |
| 24-27° C (76-80° F) | 0.9 gpm | 0.8 gpm |
| 27-29° C (81-84° F) | 1.0 gpm | 0.9 gpm |
| 29-32° C (85-89° F) | 1.1 gpm | 1.0 gpm |
| 32-34° C (90-94° F) | 1.2 gpm | 1.1 gpm |
| 35-37° C (95-98° F) | 1.3 gpm | 1.2 gpm |
| 37-39° C (99-103° F) | 1.4 gpm | 1.3 gpm |
| 40-42° C (104-108° F) | 1.5 gpm | 1.4 gpm |
| 43-44° C (109-112° F) | 1.6 gpm | 1.5 gpm |
| 45-47° C (113-117° F) | 1.7 gpm | 1.6 gpm |
| 48-49° C (118-120° F) | 1.8 gpm | 1.7 gpm |
Minimum Flow Rate in Gallons Per Minute (GPM)
Back Flush Procedure
- Connect the J 45096 adapters (1) to the vehicle's transmission oil cooler supply and return lines at the transmission. It may require the use of J 35944-200 cooler flushing adapter.
- Connect the black supply hose (1) to the return line, rear connector of the transmission, and the clear waste hose (2) to the feed line, front connector of the transmission, to the vehicle cooler lines. This is the reverse flow - backflush direction.
- Turn the main function switch to the FLUSH position. Allow the machine to operate for 30 seconds.
- Turn the main function switch to the IDLE position and allow the supply vessel pressure to dissipate.
- Disconnect the supply and waste hoses from the vehicle cooler lines. Reverse the supply and waste hoses to provide a normal flow direction.
- Turn the main function switch to the FLUSH position and allow machine to operate for 30 seconds.
- 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.
- 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 the 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.
- If the TESTED flow rate is less than the MINIMUM flow rate after the second test, perform the Code Recording Procedure. Replace the transmission oil cooler. Connect the supply and waste hoses to the cooler lines in the normal flow direction. Perform the Flow Test. Perform the Code Recording Procedure.
Code Recording Procedure
- Turn the main function switch to the CODE position.
- Record TESTED flow rate, temperature, cycle and seven-character flow code information on repair order.
- Turn the main function switch to the IDLE position and allow the supply vessel pressure to dissipate.
- Turn the main power switch to the OFF position.
- Disconnect the supply and waste hoses and the 12-volt power source from the vehicle.
- Disconnect the air supply hose from J 45096 .
- Dispose of the waste ATF in accordance with all applicable federal, state, and local requirements.
Automatic Transmission Fluid Leaks
| Checks | Cause |
|---|---|
| Oil Pan Fluid Leak | |
| Oil Pan (28) | The pan is damaged or the pan is not flat. |
| Gasket (29) | Damaged or mispositioned |
| Case (7) | Porosity or cracked |
| Bolt (27) | The flange is inside out. High or low torque |
| Fill Tube Fluid Leak | |
| Seal | Cut or nicked Missing |
| Case (7) | Porosity |
| Fill Tube | Damaged at the case end Not seated in the case |
| Brackets | Out of position, causing tension on the fill tube |
| Electrical Connector Fluid Leak | |
| Electrical Connector | Damaged, or not seated |
| O-ring Seal | Cut or nicked Missing |
| Case (7) | Porosity or cracked |
| Cooler Connector Fluid Leak | |
| Cooler Connectors (8) | Stripped threads Damaged flare High or low torque |
| Case (7) | Stripped threads Porosity Debris in the threads |
| Case Extension Fluid Leak | |
| Case Extension (19) | Porosity or cracked |
| Case (7) | Porosity or cracked |
| Seal (15) | Cut or nicked Missing |
| Bolt (21) | Low torque Missing |
| Manual Shaft Fluid Leak | |
| Seal (707) | Cut or nicked Not seated |
| Linkage | Misadjusted |
| Pump Body Seal Fluid Leak | |
| Seal (201) | Cut, nicked, or worn Missing garter spring |
| Torque Converter (1) | Damaged hub |
| Bolt | Low Torque |
| Vehicle Speed Sensor Fluid Leak | |
| Seal | Cut, missing, or nicked |
| Vehicle Speed Sensor Assembly (22) | Damaged Not seated Damaged bracket |
| Bolt (23) | Low torque Missing Damaged threads |
| Case (7) | Porosity or cracked |
| Output Shaft Seal Fluid Leak | |
| Seal (20) | Cut or nicked |
| Case (7) | Porosity or cracked |
| Line Pressure Plug Fluid Leak | |
| Plug (24) | Stripped threads Low or high torque |
| Case (7) | Porosity or cracked Damaged threads |
Automatic Transmission Fluid Leaks
High Line Pressure
| Checks | Cause |
|---|---|
| Pressure Regulator Valve (231) | Valve is stuck at high torque signal due to an undersized bore or sediment. |
| Reverse Boost Valve (228) | Valve is stuck at high torque signal due to an undersized bore or sediment. |
| Retainer Pin (211) | Pin is broken |
| Orificed Plug (210) | Plug is blocked |
| Pressure Control Solenoid Valve (320) | Valve has failed Off Loose connector |
| PCM | Loose connector |
| Check the PCM for current DTCs. | |
High Line Pressure
Forward Motion in Neutral
| Checks | Cause |
|---|---|
| Manual Valve (319) | Valve is mispositioned or stuck. |
| Forward Clutch Springs (607) | Jammed |
| Forward Clutch Piston (606) | Jammed |
| Forward Clutch Plates (610, 611) | Seized or jammed |
| Forward Clutch Housing (602) | The hole is plugged. |
| Hub (613) | The holes are plugged. |
Forward Motion in Neutral
Inadequate Lubrication at Low Line or Heavy Loads
| Checks | Cause |
|---|---|
| Converter Limit Valve (214) | Valve is stuck closed by sediment or by a collapsed valve bore. |
| Retainer Pin (211) | Broken |
Inadequate Lubrication at Low Line or Heavy Loads
Inadequate Lubrication
| Checks | Cause |
|---|---|
| Pressure Regulator Valve (231) | Valve is stuck in a high demand position. |
| Pump Body (206) | Cross channel leakage |
| Gasket (6) | Damaged |
| Oil Transfer Hole Cup Plug | Plug is leaking |
Inadequate Lubrication
Engine Stall in Neutral
| Checks | Cause |
|---|---|
| TCC System | TCC is stuck On or TCC is not released. |
Engine Stall in Neutral
Loss of Power
| Checks | Cause |
|---|---|
| Transmission | Low oil Not starting in first gear |
| TCC System | TCC is stuck On, or TCC is dragging. |
| Torque Converter (1) | Debris in the converter Stator loose |
| Stator Shaft (235) | The shaft is broken. |
| Turbine Shaft (502) | The bushing is worn. |
| Mainshaft (662) | The bushing is worn. |
| Output Shaft (671) | The bushing is worn. |
| Bearing (668) | The bearing is worn. |
Loss of Power
No Torque in Reverse and Third
| Checks | Cause |
|---|---|
| Forward Clutch Hub (613) | The hub is broken. |
| Snap Ring (616a) | The ring is not seated. |
| Forward Clutch Housing (602) | The housing is broken. |
| Direct Clutch Piston (619) | The piston is broken. |
No Torque in Reverse and Third
Transmission Overheats
| Checks | Cause |
|---|---|
| TCC Circuit | Blockage during apply or release |
| TCC Valve Spring (224) | The spring is broken. |
| Pump Cover (206) | Cross channel leakage |
| Pressure Regulator Valve (231) | The valve is stuck in a high demand position. |
| Oil Cooler | The cooler or the cooler lines are blocked. |
| Gasket (6) | The gasket is damaged. |
| Retainer Pin (211) | The pin is broken. |
| Turbine Shaft O-ring (2) | The O-ring is damaged. |
| Turbine Shaft Seals (503) | The seals are damaged. |
| Stator Shaft Bushing (233) | The bushing is worn or damaged. |
| Oil Transfer Hole Cup Plug | The plug is leaking. |
| Fluid | The fluid level is low. |
| Radiator | Air flow is restricted. |
Transmission Overheats
Transmission Overheats at WOT
| Checks | Cause |
|---|---|
| Converter Limit Valve Bypass Orificed Cup Plug | The plug is blocked, therefore the converter limit valve is stuck closed. |
Transmission Overheats at WOT
Low Line Pressure
| Checks | Cause |
|---|---|
| Pump (203) | Cross channel leak at body to cover, or cross channel leak at body to case gasket |
| Pressure Regulator Valve (231) | Valve is stuck at a low torque signal due to an undersized bore or to sediment. |
| Reverse Boost Valve (228) | Valve is stuck at a low torque signal due to an undersized bore or to sediment. |
| Pump Valve Bores | Excessive valve clearance due to wear. |
| Spring (230) | The spring is broken. |
| Retainer Pin (211) | The pin is broken. |
| Valve Body (301) | Cross channel leaks Cross valve land leaks |
| Gasket/Spacer Plate | The plate is damaged or missing. |
| Pressure Control Solenoid Valve (320) | The valve is stuck On. A broken clip causes leakage. A wire is pinched to ground. A screen is missing. |
| PCM | Failed |
| Check the PCM for current DTCs. | |
Low Line Pressure
Engine Starts in Gear
| Checks | Cause |
|---|---|
| Manual Valve (319) | Valve is not engaged to the detent lever. Valve is stuck in the wrong position. |
| Park/Neutral Safety Switch | The switch is not operating. |
Engine Starts in Gear
Shift Lever Indicates Wrong Gear
| Checks | Cause |
|---|---|
| Manual Valve (319) | Not engaged to detent lever |
| Detent Pin (711) | Misaligned or broken |
| Manual Shaft (708) | The flats are not parallel. |
| Indicator Linkage | Misadjusted |
Shift Lever Indicates Wrong Gear
No Gear Selection
| Checks | Cause |
|---|---|
| Detent Lever (711) | The nut is loose or missing. |
| Manual Valve (319) | The valve is stuck. |
| Spacer Plate (46) | The holes are blocked. |
| Valve Body/Case (301, 7) | The channels are blocked. |
No Gear Selection
Loss of Drive
| Checks | Cause |
|---|---|
| Torque Converter (1) | Broken lug or failed lug welds Sheared lug bolts Worn turbine shaft splines Low oil The pump hub is cracked, scored, or broken. Internal failure Failure of the closure weld The cover is cracked at a lug weld. |
| Pump (203) | The pump is seized. The pump gears are broken. |
| Case Extension Seal (20) | The seal is missing, damaged, or displaced. |
| Orifice Plate | The plate is missing or leaking around the edge. |
| Gasket (6) | Damaged |
| Oil Transfer Hole Cup Plug | The plug is leaking or missing. |
| Seals (503) | The seals are damaged or missing. |
| Housing (504) | The housing is broken. |
| Roller Clutch (512) | The clutch is worn, broken, or locked. |
| Carrier (514) | Broken |
| Pinions (518) | Broken free from the pilot Spalled pins or pinions Plugged pinion pin holes Worn thrust washers Lack of lube |
| Bearing (513) | The bearing is broken. |
| Roller Clutch (644) | The clutch is worn, broken, or locked. Lack of lube |
| Turbine Shaft (502) | The shaft or the splines are broken. |
| Forward Clutch Components | |
| Seals (603, 604, 605) | Nicked or cut |
| Checkball | Leaking |
| Piston (606) | Cracked or jammed |
| Housing (602) | Cracked |
| Friction Plates (611) | The plates are burned or the splines are worn. |
| Reaction Plates (610) | The plates are worn or the splines are worn. |
| Spring Assembly (607) | Jammed |
| Driving Hub (615) | Broken |
| Retainer Ring (616) | The ring is not seated. |
| Driven Hub (613) | The gear teeth are worn. |
| Rear Gear Set | |
| Pinions (655) | Broken or spalled |
| Pinion Pins (656) | Broken or spalled |
| Needle Bearings (654) | Broken or spalled |
| Sun Gear (649) | Broken or spalled |
| Pinion Thrust Washers (652) | Worn |
| Rear Internal Gear (666) | Broken or spalled |
| Front Internal Gear (661) | Broken or spalled |
| Turbine Shaft Ball Seal | Ineffective |
| Mainshaft (662) | The shaft or the splines are broken. |
| Fluid Pressure | Too low |
Loss of Drive
No Park
| Checks | Cause |
|---|---|
| Detent Lever (711) | Incomplete travel Lever is misaligned |
| Actuator Rod (710) | The rabbit ears are bent, disconnected, or broken. |
| Detent Spring (41) | Mispositioned |
| Parking Pawl (703) | Broken |
| Pawl Shaft (702) | Broken |
| Park Bracket (713) | Bent or broken |
| Bolt (714) | Loose or broken |
| Front Internal Gear (661) | The splines are broken. |
| Manual Shaft (708) | The flats are not parallel. |
No Park
Remains in Park
| Checks | Cause |
|---|---|
| Actuator Rod Assembly (710) | Stretched |
Remains in Park
Difficult to Shift Out of Park
| Checks | Cause |
|---|---|
| Pawl Return Spring (705) | Weak or broken |
| Vehicle | Parked on a hill |
Difficult to Shift Out of Park
Does Not Stay in Park
| Checks | Cause |
|---|---|
| Detent Spring (41) | Weak or broken |
Does Not Stay in Park
No Reverse
| Checks | Cause |
|---|---|
| Case (7) | The rear band anchor pin is broken or the pin is not positioned. |
| Center Support (640) | Leaking at the case, or the support is broken. |
| Center Support Seal (639) | Leaking |
| Center Support Bolt (25) | The bolt is loose or broken. The feed hole is blocked. |
| Rear Band (657) | Broken, worn, or not anchored |
| Rear Band Apply Pin (73) | The pin is too short or the pin is binding in the case. |
| Piston (65) | Binding in the case |
| Seal (66) | Leaking, damaged, or worn |
| Gasket (63) | Damaged or displaced |
| Cover (62) | Damaged |
| Bolts (61) | Broken, loose, or missing |
| Checkball | Missing |
| Fluid Pressure | Too low |
| Direct Clutch Components | |
| Reaction Plates (618) | The splines are worn. |
| Friction Plates (611) | The splines or the friction are worn. |
| Spring Assembly (607) | Jammed |
| Housing (623) | Cracked |
| Piston (619) | Leaking |
| Seal (620, 621, 622) | Leaking |
| Ball Check | Leaking |
No Reverse
No First Gear - D1
| Checks | Cause |
|---|---|
| Refer to No First Gear - D4 | |
| Housing (504) | Broken |
| Case (7) | The rear band anchor pin is broken or the pin is not positioned. |
| Detent Lever (711) | Misaligned |
No First Gear - D1
No Second Gear - D1
| Checks | Cause |
|---|---|
| Refer to No Second Gear - D4 . | |
No Second Gear - D1
No Overrun Braking - D1
| Checks | Cause |
|---|---|
| Refer to No Overrun Braking - D3 . | |
| Check the PCM for current DTCs. | |
| Automatic Transmission Fluid Pressure Manual Valve Position Switch Assembly | Pinched wire Loose connector Loose bolt causing leakage No signal to the PCM. |
No Overrun Braking - D1
No Engine Braking - D1
| Checks | Cause |
|---|---|
| Rear Band (657) | Damaged, worn, or not anchored |
| Rear Band Apply Pin (73) | The pin is too short or is binding in the case. |
| Piston (65) | The piston is binding in the case. |
| Seal (66) | Worn or damaged |
| Cover (62) | Damaged |
| Gasket (63) | Damaged or missing |
| Bolt (61) | Loose, broken, or missing |
| Checkball | Missing Damaged Not sealing Incorrect size |
| Fluid Pressure | Too low |
| Output Shaft (671) | The shaft or the splines are broken. |
| Mainshaft (662) | The shaft or the splines are broken. |
| Thrust Washer (218) | Worn or damaged |
| Bushing (234) | Worn or damaged |
No Engine Braking - D1
No First Gear - D2
| Checks | Cause |
|---|---|
| Refer to No First Gear - D4 . | |
| Front Band (628) | Stuck On |
No First Gear - D2
No Second Gear - D2
| Checks | Cause |
|---|---|
| Refer to No Second Gear - D4 . | |
| Case (7) | The front band anchor pin is broken or the pin is not properly positioned. The intermediate clutch feed cup plug is missing or the plug is not seated. |
No Second Gear - D2
No Overrun Braking - D2
| Checks | Cause |
|---|---|
| Refer to No Overrun Braking - D3 . | |
No Overrun Braking - D2
No Engine Braking - D2
| Checks | Cause |
|---|---|
| Bushing (234) | Worn or damaged |
| Thrust Washer (218) | Worn or damaged |
| Rear Gear set | Spalled or broken |
| Reaction Drum and Carrier (651) | Broken |
| Mainshaft (662) | The shaft or the splines are broken. |
| Output Shaft (671) | The shaft or the splines are broken. |
| Sun Gear Shaft (649) | The shaft or the splines are broken. |
No Engine Braking - D2
No Second Gear Engine Braking - D2
| Checks | Cause |
|---|---|
| Fluid Pressure | Too low |
| Direct Clutch Housing (623) | The internal diameter of the splines are worn. The outer band surface is worn. |
| Front Band (628) | Broken, worn, or not anchored |
| Apply Pin (55) | Too short or binding in the case |
| Apply Clip (56) | Broken or missing |
| Piston (58) | Cracked, broken, or binding |
| Seal (57) | Damaged or worn |
| Case (7) | Cracked or damaged |
| Spacer Plate (46) | Damaged |
| Gasket (48) | Torn or pinched |
| Valve Body Bolts (35) | Loose, broken, or missing |
No Second Gear Engine Braking - D2
No First Gear - D3
| Checks | Cause |
|---|---|
| Refer to No First Gear - D4 . | |
| Front Band (628) | Stuck On |
No First Gear - D3
No Second Gear - D3
| Checks | Cause |
|---|---|
| Refer to No Second Gear - D4 . | |
No Second Gear - D3
No Third Gear - D3
| Checks | Cause |
|---|---|
| Refer to No Third Gear - D4 . | |
| Front Band (628) | Stuck On |
No Third Gear - D3
No Overrun Braking - D3
| Checks | Cause |
|---|---|
| Clutch Plates (508, 509) | The splines or the plate are worn. |
| Thrust Washer (218) | Damaged or worn |
| Output Shaft (671) | The shaft or the splines are broken. |
| Seals | Cut or nicked |
| Checkball | Leaking |
| Piston (505) | Jammed, cracked, or damaged |
| Housing (504) | Cracked or damaged |
| Sun Gear (650) | Worn |
| Spring Assembly (506) | Jammed |
| Oil Feed | Plugged |
No Overrun Braking - D3
No Engine Braking - D3
| Checks | Cause |
|---|---|
| Mainshaft (662) | The shaft or the splines are broken. |
| Bushing (234) | Damaged or worn |
No Engine Braking - D3
No First Gear - D4
| Checks | Cause |
|---|---|
| Low Roller Assembly (644) | Assembly is not attached Broken race |
| Center Support (640) | Broken support or broken splines |
| Case (7) | Check for damage near the center support. |
| Retainer Rings (633, 643) | Rings are not seated. |
No First Gear - D4
First Gear Only - D4
| Checks | Cause |
|---|---|
| Sun Gear Shaft (649) | Broken shaft or broken splines |
| AT Output Speed Sensor Assembly (22) | Reads zero Check for DTCs. |
| AT Input Speed Sensor Assembly (22) | Reads zero Check for DTCs. |
First Gear Only - D4
First and Second Gear Only - D4
| Checks | Cause |
|---|---|
| 2-3 Solenoid (311) Check for DTCs. | Stuck Off Loose connector No voltage to the solenoid Solenoid O-ring failure No PCM signal to the solenoid |
| 2-3 Shift Valve (312) | Stuck |
| Check the PCM for current DTCs. | |
First and Second Gear Only - D4
Second Gear Only - D4
| Checks | Cause |
|---|---|
| Check the PCM for current DTCs. | |
Second Gear Only - D4
Second and Third Gear Only - D4
| Checks | Cause |
|---|---|
| 1-2 Solenoid (313) Check for DTCs. | Stuck Off Loose connector No voltage to the solenoid Solenoid O-ring failure No PCM signal to the solenoid |
| 1-2 Shift Valve (314) | Stuck |
| PCM | Failed |
| Check the PCM for current DTCs. | |
Second and Third Gear Only - D4
First and Fourth Gear Only - D4
| Checks | Cause |
|---|---|
| 1-2 Solenoid (313) | Stuck On Pinched wire to ground |
| 1-2 Shift Valve (314) | Stuck |
| PCM | Failed |
| Check the PCM for current DTCs. | |
First and Fourth Gear Only - D4
Third and Fourth Gear Only - D4
| Checks | Cause |
|---|---|
| 2-3 Solenoid (311) | Stuck On Pinched wire to ground |
| 2-3 Shift Valve (312) | Stuck |
| PCM | Failed |
| Check the PCM for current DTCs. | |
Third and Fourth Gear Only - D4
No Second Gear - D4
| Checks | Cause |
|---|---|
| Case (7) | The intermediate clutch feed cup plug is missing or the cup plug is not seated. |
| Intermediate Clutch Components | |
| Backing Plate (630) | Broken |
| Retainer Ring (633) | Missing or not seated |
| Friction Plates (631) | Worn |
| Outer Race (625) | Worn Splines |
| Center Support (640) | The support is cracked or the feed hole is blocked. |
| Center Support Bolt (25) | The bolt is broken or loose. The oil hole is blocked. |
| Seals (637, 638) | Worn |
| Piston (636) | Cracked or jammed |
| Springs (635) | Jammed |
| Transmission Fluid | Improper fluid Additive package |
| Intermediate Sprag (624) | The outer race splines are worn. The outer race is broken. The splines or the inner race is worn. |
| Direct Clutch Housing (623) | Broken |
| Retainer Ring (627) | Missing or not seated |
No Second Gear - D4
No Third Gear - D4
| Checks | Cause |
|---|---|
| Direct Clutch Components | |
| Seal (620, 621, 622) | Leaking |
| Ball Check | Leaking |
| Piston (619) | Cracked or jammed |
| Housing (623) | Cracked |
| Reaction Plates (618) | Worn splines |
| Friction Plates (611) | Worn splines or worn friction |
| Spring Assembly (607) | Jammed |
| Center Support Seals (639) | The seals are leaking at the center support hub. |
| Center Support (640) | The support is broken or leaking at the case. |
| Center Support Bolt (25) | Loose or broken Blocked hole |
| 2-3 Solenoid (311) | Stuck Off Pinched wire O-ring failure No voltage to the solenoid |
| PCM | No signal to the solenoid |
| 2-3 Shift Valve (312) | Stuck |
| PCM | Failed |
| Check the PCM for current DTCs. | |
No Third Gear - D4
No Fourth Gear - D4
| Checks | Cause |
|---|---|
| Fourth Clutch Components | |
| Seals (527) (531) | Nicked or cut |
| Cup Plug (530) | Missing |
| Bolt (26) | Loose, broken, or missing |
| Piston (528) | Jammed |
| Spring Assembly (532) | Jammed |
| Retainer Ring (523) | Not seated |
| Friction Plates (525) | Worn or burned |
| Reaction Plates (526) | Worn splices |
| Housing (529) | Damaged or cracked |
| Overrun Clutch Components | |
| Housing (504) | Broken |
| Reaction Plates (508) | Worn splines |
| Sun Gear (650) | Worn |
| 1-2 Solenoid (313) | Stuck Off Pinched wire O-ring failure No voltage to the solenoid |
| PCM | No signal to the solenoid Failed |
| 3-4 Shift Valve (308) | Stuck |
| Check the PCM for current DTCs. | |
No Fourth Gear - D4
No Torque Converter Clutch (TCC) Apply
| Checks | Cause |
|---|---|
| TCC Shift Solenoid Valve (323) | Stuck Off O-ring failed No voltage to the solenoid Poor connection |
| PCM | Failed No signal to the solenoid |
| Brake Switch | The contact is corroded. Poor connection Pinched wire Misadjusted No supply voltage |
| TCC Valve (223) | The valve is stuck Off due to sediment or to an undersized bore. |
| Retainer Pin (211) | Broken |
| Torque Converter (1) | Ballooning |
| Turbine Shaft (502) | Plugged oil holes |
| Turbine Shaft Seals (501) | Ineffective |
| Pump Body Bushing (202) | Worn |
| O-ring (2) | Heat set |
| Oil Transfer Hole Cup Plug | Leaking |
| Regulated Apply Valve (324) | Stuck |
| TCC Valve Release Exhaust Orificed Cup Plug | Blocked |
| Check PCM for the current DTCs. | |
| Refer to Incorrect Torque Converter Clutch (TCC) Apply or Release . | |
No Torque Converter Clutch (TCC) Apply
Soft Torque Converter Clutch (TCC) Apply
| Checks | Cause |
|---|---|
| Turbine Shaft Seals (501) | Ineffective |
| Pump Body Bushing (202) | Worn |
| O-ring (2) | Heat set |
| Oil Transfer Hole Cup Plug | Leaking |
| TCC Solenoid (323) | Malfunction |
| Fluid | Low pressure |
Soft Torque Converter Clutch (TCC) Apply
Torque Converter Clutch (TCC) Slipping
| Checks | Cause |
|---|---|
| TCC Valve Release Exhaust Orificed Cup Plug | Blocked |
| Turbine Shaft Seal | Cut |
Torque Converter Clutch (TCC) Slipping
Torque Converter Clutch (TCC) Stuck On
| Checks | Cause |
|---|---|
| Gasket (6) | Damaged |
| TCC Shift Solenoid Valve (323) | Stuck On Pinched wire to ground |
| TCC Apply Valve (324) | Stuck |
| PCM | Failed |
| Check PCM for current DTCs | |
| Refer to Incorrect Torque Converter Clutch (TCC) Apply or Release . | |
Torque Converter Clutch (TCC) Stuck On
Incorrect Torque Converter Clutch (TCC) Apply or Release
| Checks | Cause |
|---|---|
| AT Output Shaft Speed Sensor Assembly (22) | Poor connection Pinched wire A broken coil wire Incorrect air gap Inadequate signal |
| Throttle Position Sensor | Poor connection Pinched wire Incorrect resistance |
| PCM | Failed |
| Automatic Transmission Fluid Pressure Manual Valve Position Switch (40) | Poor connection No signal to the PCM Pinched wire |
| AT Fluid Temperature Sensor Assembly (332) | Poor connection No signal to the PCM Incorrect resistance Pinched wire |
| Engine Coolant | No signal to the PCM |
| Brake Switch | Poor connection Pinched wire No voltage supply Misadjusted |
| Engine Ignition Module | Loss of signal or intermittent |
| Check the PCM for current DTCs. | |
| Only 2WD | |
Incorrect Torque Converter Clutch (TCC) Apply or Release
Converter Ballooning
| Checks | Cause |
|---|---|
| Converter Limit Valve (214) | Stuck open due to sediment or undersized bore |
| At High Speeds: Converter Limit Valve Feedback Orificed Cup Plug | Blocked |
| Converter Stator | Locked-up |
Converter Ballooning
No Torque Multiplication
| Checks | Cause |
|---|---|
| Stator Shaft (235) | Broken or detached from the pump cover |
No Torque Multiplication
Fluid Foaming
| Checks | Cause |
|---|---|
| Fluid | Contaminated antifreeze Overfilled transmission |
| Engine | Overheated |
| Filter (31) | Cracked or not seated |
| Seal (32) | Damaged or not seated |
| Vehicle | Overloaded |
Fluid Foaming
Noise
| Checks | Cause |
|---|---|
| Torque Converter (1) | Loose lug bolts Out of balance Internal failure |
| Transmission/Engine | Misaligned |
| Case Extension (19) | Output shaft support bushing is worn. |
| Reaction and Output Gear Sets | Flats on gear teeth or teeth improperly machined |
| Oil Pan | Dented |
Noise
Engine Stall
| Checks | Cause |
|---|---|
| Fourth Clutch Components | |
| Plates (525, 526) | Seized or jammed |
| Piston (528) | Jammed |
| Spring Assembly (532) | Jammed |
| Overrun Clutch Components | |
| Plates (508, 509) | Seized or jammed |
| Piston (505) | Jammed |
| Spring Assembly (506) | Jammed |
| Cooler Lines | Kinked or plugged |
| Transmission Oil Cooler | Plugged |
Engine Stall
Vibration
| Checks | Cause |
|---|---|
| Torque Converter (1) | Out of balance Internal failure Not sealed in crankshaft pilot |
| Transmission/Engine | Misaligned or missing dowels |
| Case Extension (19) | Output shaft support bushing is worn. |
| Turbine Shaft (502) | Worn surface of the stator shaft bushing |
| Mainshaft (662) | Worn bushing |
| Output Shaft (671) | Worn bushing |
| Bearing (668) | Worn |
Vibration
Oil Out the Vent Tube
| Checks | Cause |
|---|---|
| Pump Cover (206) | Cross channel leakage can pressurize the vent area. |
| Fluid | Foaming and filling the pump vent ports Transmission is overfilled. |
| Transmission | Overheated |
Oil Out the Vent Tube
No Torque in Second Gear
| Checks | Cause |
|---|---|
| Intermediate Sprag (624) | Worn Excessive eccentricity The sprag is rolled over or the sprag is damaged. |
No Torque in Second Gear
Second Gear Starts
| Checks | Cause |
|---|---|
| Intermediate Clutch Plates (631, 632) | Seized |
| Direct Clutch Lube Feed | Blocked |
| Center Support Springs (635) | Jammed |
| Center Support Piston (636) | Jammed |
| 1-2 Shift Solenoid Valve (313) | Stuck Off O-ring failed No voltage to the solenoid Poor connection |
| PCM | No PCM signal to the solenoid Failed |
| 1-2 Shift Valve (314) | Stuck |
| Check the PCM for current DTCs. | |
Second Gear Starts
Third Gear Starts
| Checks | Cause |
|---|---|
| Forward Clutch Components | |
| Driving Hub (615) | Plugged holes |
| Plates (610, 611) | Seized |
| Direct Clutch Components | |
| Piston (619) | Jammed |
| Spring Assembly (607) | Jammed |
| Lube Feed Hole | Blocked |
Third Gear Starts
Fourth Gear Starts
| Checks | Cause |
|---|---|
| 2-3 Shift Solenoid Valve | Stuck On Pinched wire to ground |
| Check the PCM for current DTCs. | |
Fourth Gear Starts
Erratic Shift Quality
| Checks | Cause |
|---|---|
| Gasket (6) | Damaged |
| Oil Transfer Hole Cup Plug | Leaking |
| Oil Seal Rings (219) | Damaged |
Erratic Shift Quality
Transmission Slips
| Checks | Cause |
|---|---|
| Fluid Level | Too high or too low |
| Shift Solenoids | Leaking |
| 4th Accumulator Piston Pin Retainer Ring | Missing |
Transmission Slips
Case Extension Bearing/Seal Failed
| Checks | Cause |
|---|---|
| Orifice Plate | The hole is blocked or the hole is missing. |
| Case Extension (19) | The lube passages are blocked or missing. |
Case Extension Bearing/Seal Failed
Inaccurate Shift Points
| Checks | Cause |
|---|---|
| AT Output Shaft Speed Sensor Assembly (22) | Pinched or broken wire Loose connector Incorrect air gap Inadequate signal Damaged coil Damaged rotor teeth Loose connection |
| Throttle Position Sensor | Pinched or damaged wire Incorrect resistance Loose connector PCM malfunction |
| AT Fluid Pressure Manual Valve Position Switch Assembly (40) | Loose connector Loose bolts causing leakage A pinched wire No signal to the PCM |
| Axle Ratio | Ratio is incorrect or ratio has been changed from its original value. |
| Tire Size | Tire size is incorrect or the size has been changed from its original value. |
| Check the PCM for current DTCs. | |
Inaccurate Shift Points
Harsh Shifts
| Checks | Cause |
|---|---|
| Line Pressure | Too high |
| Pressure Control Solenoid Valve (320) | Failed Off Loose connector |
| PCM | Loose connector |
| Accumulator Piston | Leaking Stuck |
| Accumulator Spring | Incorrect |
| Checkballs | Missing |
| Calibration PROM | Incorrect |
| Check the PCM for current DTCs. | |
Harsh Shifts
Harsh Shift D to R
| Checks | Cause |
|---|---|
| Direct Lube Exhaust | Blocked |
| Forward Clutch Spring (607) | Not acting |
| Retainer Ring (616) | Not seated |
| Checkball Orifice | Plugged |
Harsh Shift D to R
Harsh Shift 3 to 4
| Checks | Cause |
|---|---|
| Spring Assembly (532) | Not compressing evenly |
| Air Bleed Orifice 4th Clutch Housing (530) | Plugged |
Harsh Shift 3 to 4
Harsh Shift 4 to 3
| Checks | Cause |
|---|---|
| Retainer Ring (533) | Not seated |
| Spring Assembly (532) | Not acting |
| Bolt (26) | The oil feed hole is plugged. |
| Cup Plug (530) | Plugged |
| Direct Lube Exhaust | Blocked |
Harsh Shift 4 to 3
Harsh Shift D4 to D3, D2, or D1
| Checks | Cause |
|---|---|
| Spring Assembly (506) | Not functioning |
| Checkball Orifice | Plugged |
| Snap Ring (511) | Not seated |
| Scan Tool Shift Adapts | Maximum shift adapts |
Harsh Shift D4 to D3, D2, or D1
Soft Shifts
| Checks | Cause |
|---|---|
| Line Pressure | Too low |
| Pressure Control Solenoid Valve (320) | Stuck On A broken clip is causing leakage. Pinched wire to ground |
| PCM | Failed |
| Accumulator Piston | Leaking Stuck |
| Accumulator Spring | Incorrect |
| Calibration PROM | Incorrect |
| Check the PCM for current DTCs. | |
| Shift Solenoids | Leaking |
| 4th Accumulator Piston Pin Retainer Ring | Missing |
Soft Shifts
Soft Shift into R
| Checks | Cause |
|---|---|
| Direct Clutch Oil Feed | Plugged |
| Direct Lube Exhaust | Blocked |
Soft Shift into R
Soft Shift R to D
| Checks | Cause |
|---|---|
| Direct Clutch Spring (607) | Not Acting |
| Retainer Ring (616) | Not engaged or missing |
| Ball Check Orifice | Plugged |
Soft Shift R to D
Soft Shift 2 to 1
| Checks | Cause |
|---|---|
| Center Support Springs (635) | Not acting |
| Retainer Ring (634) | Not seated |
| Center Support (640) | Blocked air bleed |
Soft Shift 2 to 1
Soft Shift 2 to 3
| Checks | Cause |
|---|---|
| Direct Clutch Oil Feed | Plugged |
| Direct Lube Exhaust | Blocked |
Soft Shift 2 to 3
Soft Shift 3 to 2
| Checks | Cause |
|---|---|
| Direct Spring Assembly (607) | Not acting |
| Retainer Ring (608) | Not engaged or missing |
| Ball Check Orifice | Plugged |
Soft Shift 3 to 2
Soft Shift D3 to D2
| Checks | Cause |
|---|---|
| Ball Check | Missing |
| Orifices | Incorrect sizes |
Soft Shift D3 to D2
Delayed Shift 1 to 2
| Checks | Cause |
|---|---|
| AT Output Shaft Speed Sensor Assembly (22) | A pinched or broken wire A loose connector An incorrect air gap An inadequate signal Coil damage |
| AT Input Shaft Speed Sensor Assembly (22) | A pinched or damaged wire Coil damage An inadequate signal |
| AT Fluid Pressure Manual Valve Position Switch Assembly (40) | A loose connector A pinched wire No signal to the PCM Loose bolts causing leakage |
| Calibration PROM | Incorrect |
| Check the PCM for current DTCs. | |
Delayed Shift 1 to 2
No D2 to D1
| Checks | Cause |
|---|---|
| Rear Band (657) | Broken, worn, or not anchored |
| Detent Lever (711) | Incomplete travel |
No D2 to D1
No D3 to D2
| Checks | Cause |
|---|---|
| Front Band (628) | Broken, worn, or not anchored |
No D3 to D2
See also:
• Transmission Range Switch Logic
• Intermittent Conditions
• Instrument Panel Cluster (IPC) Replacement
• Testing for Short to Ground
• Wiring Repairs
• Testing for Continuity
• Circuit Testing
• Park/Neutral Position Switch Replacement
• Powertrain Control Module (PCM) Replacement
• Diagnostic Starting Point - Body Control System
• Line Pressure
• Scan Tool Data List
• Shift Speed
• Lifting and Jacking the Vehicle
• Engine Flywheel Cleaning and Inspection
• Diagnostic Starting Point - Vibration Diagnosis and Correction
• Noise and Vibration Analysis
• Valve Body and Pressure Switch Replacement
• Fluid Capacity Specifications
• Transmission Fluid Checking Procedure
• Fluid Foaming
• Transmission Overheats
• Transmission Overheats at WOT
• High Line Pressure
• Low Line Pressure
• Inadequate Lubrication at Low Line or Heavy Loads
• Inadequate Lubrication
• Fluid Leak Diagnosis
• Case Extension Bearing/Seal Failed
• Oil Out the Vent Tube
• Automatic Transmission Fluid Leaks
• Noise
• Vibration
• Forward Motion in Neutral
• No Park
• No Reverse
• Engine Stall
• No Torque in Reverse and Third
• Loss of Power
• No Torque in Second Gear
• Loss of Drive
• No Overrun Braking - D1
• No Engine Braking - D1
• No Overrun Braking - D2
• No Engine Braking - D2
• No Second Gear Engine Braking - D2
• No Overrun Braking - D3
• No Engine Braking - D3
• Engine Starts in Gear
• Shift Lever Indicates Wrong Gear
• No Gear Selection
• Remains in Park
• Difficult to Shift Out of Park
• Does Not Stay in Park
• Erratic Shift Quality
• Harsh Shifts
• Transmission Slips
• Harsh Shift 3 to 4
• Harsh Shift 4 to 3
• Harsh Shift D4 to D3, D2, or D1
• Soft Shifts
• Delayed Shift 1 to 2
• Soft Shift 2 to 3
• Soft Shift D3 to D2
• Soft Shift 3 to 2
• No D3 to D2
• No D2 to D1
• Harsh Shift D to R
• Soft Shift into R
• Soft Shift R to D
• No First Gear - D1
• No First Gear - D2
• No First Gear - D4
• No Second Gear - D1
• No Second Gear - D2
• No Second Gear - D4
• No Second Gear - D3
• No Third Gear - D3
• No Third Gear - D4
• No Fourth Gear - D4
• First Gear Only - D4
• Second Gear Only - D4
• First and Second Gear Only - D4
• First and Fourth Gear Only - D4
• Second and Third Gear Only - D4
• Third and Fourth Gear Only - D4
• Second Gear Starts
• Third Gear Starts
• Fourth Gear Starts
• Inaccurate Shift Points
• Torque Converter Diagnosis Procedure
• No Torque Converter Clutch (TCC) Apply
• Torque Converter Clutch (TCC) Stuck On
• Soft Torque Converter Clutch (TCC) Apply
• Incorrect Torque Converter Clutch (TCC) Apply or Release
• No Torque Multiplication
• Torque Converter Clutch (TCC) Slipping
• Converter Ballooning
• Engine Stall in Neutral
• Road Test Procedure
• Symptoms - Automatic Transmission