Automatic Transmission - 4L80-E/4L85-E (Troubleshooting): Other Chevrolet Silverado 3500

Tools Required

J 21867 Pressure Gage

Line Pressure Check Procedure

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

Line Pressure Check Procedure

Scheme 478

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

1. Install a scan tool.
2. Start the engine and set the parking brake.
3. Check for diagnostic trouble codes, including the diagnostic code for a pressure control solenoid.
4. 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.
5. Put the gear selector in PARK and set the parking brake.
6. Start the engine and allow the engine to warm up at idle.
7. Access the Override Pressure Control Solenoid test on the scan tool.
8. 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.
9. Compare your data to the Drive-Park-Neutral «Line Pressure»(ref-184171-S04908034642005082200000) .
10. Remove the J 21867 .
11. 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.

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.

1. Connect the scan tool.
2. Ensure the gear selector is in PARK and set the parking brake.
3. Start the engine.
4. Verify that the following scan tool data can be obtained and is functioning properly. Refer to «Scan Tool Data List»(ref-184228-S14411406432005082200000) 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
5. 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
6. Check the garage shifts Apply the brake pedal and ensure the parking brake is set. Move the gear selector through the following ranges: PARK to REVERSE REVERSE to NEUTRAL NEUTRAL to DRIVE Pause 2-3 seconds in each gear position. Verify the gear engagements are immediate and not harsh.
7. 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.
8. 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.

Part Throttle Detent Downshift

1. Place the gear selector in the OVERDRIVE position.
2. Accelerate the vehicle to 64-88 km/h (40-55 mph) in FOURTH gear.
3. Quickly increase throttle angle to greater than 50 percent.
4. Verify the following: The TCC releases The transmission downshifts immediately to THIRD gear

Full Throttle Detent Downshift

1. Place the gear selector in the OVERDRIVE position.
2. Accelerate the vehicle to speeds of 64-88 km/h (40-55 mph) in FOURTH gear.
3. Quickly increase throttle angle to 100 percent (WOT).
4. 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

1. Place the gear selector in the OVERDRIVE position.
2. Accelerate the vehicle to 64-88 km/h (40-55 mph) in FOURTH gear.
3. Release the throttle while moving the gear selector to THIRD.
4. Verify the following: The transmission downshifts immediately to THIRD gear The engine slows the vehicle

Manual 4-2 Downshift

1. Place the gear selector in the OVERDRIVE position.
2. Accelerate the vehicle to 64-72 km/h (40-45 mph).
3. Release the throttle while moving the gear selector to SECOND.
4. Verify the following: The TCC releases The transmission downshifts immediately to SECOND gear The engine slows the vehicle

Manual 4-1 Downshift

1. Place the gear selector in the OVERDRIVE position.
2. Accelerate the vehicle to 64 km/h (40 mph).
3. Release the throttle while moving the gear selector to FIRST.
4. Verify the following: The TCC releases The transmission immediately downshifts to FIRST Gear. The engine slows the vehicle.

Coasting Downshifts

1. Place the gear selector in the OVERDRIVE position.
2. Accelerate the vehicle to FOURTH gear with the TCC applied.
3. Release the throttle and lightly apply the brakes.
4. Verify the following: The TCC releases Downshifts occur at speeds shown in the Shift Speed table. Refer to «Shift Speed»(ref-184171-S38811544942005082200000) .

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

1. With the vehicle stopped, move the gear selector to REVERSE.
2. Slowly accelerate the vehicle.
3. Verify that there is no noticeable slip, noise or vibration.

Manual First

1. With the vehicle stopped, move the gear selector to FIRST.
2. Accelerate the vehicle to 32 km/h (20 mph).
3. Verify the following: No upshifts occur. The TCC does not apply. There is no noticeable slip, noise, or vibration.

Manual Second

1. With the vehicle stopped, move the gear selector to SECOND.
2. Accelerate the vehicle to 57 km/h (35 mph).
3. 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

1. With the vehicle stopped, move the gear selector to THIRD.
2. Accelerate the vehicle to 64 km/h (40 mph).
3. Verify the following: The 1-2 shift occurs. The 2-3 shift occurs. There is no noticeable slip, noise, or vibration.

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.

If Shudder Occurs After TCC has Applied

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

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

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

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

Composition Plates

Dry the plates and inspect the plates for the following conditions

1. Pitting
2. Flaking
3. Delamination - splitting or separation of bonded clutch material
4. Wear
5. Glazing
6. Cracking
7. Charring
8. 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

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

Engine Coolant/Water in Transmission

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

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

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

General Method

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

Powder Method

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

Dye and Black Light Method

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

1. Follow the manufacturer's instructions in order to determine the amount of dye to use.
2. Detect the leak with the black light.
3. Make the necessary repairs.

Find the Cause of the Leak

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

Gaskets

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

Seals

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

Case Porosity Repair

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

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

J 44246 Solenoid Testing Kit

Scheme 479

1. Remove the solenoid from the control valve body. Refer to «Valve Body and Pressure Switch Replacement»(ref-184171-S11384368412005082200000) .
2. 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.
3. Connect the solenoid testing harness supplied with the J 44246 to the solenoid.
4. Apply compressed air to the J 44246 .
5. 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»(ref-184171-S11384368412005082200000) .
6. Connect the solenoid testing harness to the 12 volt positive and negative (-) battery terminals.
7. Observe if the solenoid is operating electrically. An audible clicking noise can be heard when connecting or disconnecting power.
8. 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.
9. Install the solenoid into the control valve body. Refer to «Valve Body and Pressure Switch Replacement»(ref-184171-S11384368412005082200000) .

Preparation

1. During the installation of the repaired or replacement transmission, do not connect the oil cooler pipes.
2. 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.
3. 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).
4. 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.
5. Turn ON the water supply at the faucet.

Clean-up

1. Disconnect the water supply hose from the J 35944-A and bleed any remaining air pressure from the flusher tank.
2. 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.
3. After every third use, clean the J 35944-A as described in the instructions included with the tool.
4. Dispose of any waste water/solution and transmission fluid in accordance with local regulations.

Code Recording Procedure

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

1. Turn the main function switch to the IDLE position and allow the supply vessel pressure to dissipate.
2. Turn the main power switch to the OFF position.
3. Disconnect the supply and waste hoses and the 12-volt power source from the vehicle.
4. Disconnect the air supply hose from J 45096 .
5. Dispose of the waste ATF in accordance with all applicable federal, state, and local requirements.

High Line Pressure

High Line Pressure

Forward Motion in Neutral

Forward Motion in Neutral

Engine Stall in Neutral

Engine Stall in Neutral

Loss of Power

Loss of Power

Transmission Overheats

Transmission Overheats

Transmission Overheats at WOT

Transmission Overheats at WOT

Low Line Pressure

Low Line Pressure

Engine Starts in Gear

Engine Starts in Gear

Shift Lever Indicates Wrong Gear

Shift Lever Indicates Wrong Gear

No Gear Selection

No Gear Selection

Loss of Drive

Loss of Drive

No Park

No Park

Remains in Park

Remains in Park

Difficult to Shift Out of Park

Difficult to Shift Out of Park

Does Not Stay in Park

Does Not Stay in Park

No Reverse

No Reverse

No First Gear - D1

No First Gear - D1

No Second Gear - D1

No Second Gear - D1

No Overrun Braking - D1

No Overrun Braking - D1

No Engine Braking - D1

No Engine Braking - D1

No First Gear - D2

No First Gear - D2

No Second Gear - D2

No Second Gear - D2

No Overrun Braking - D2

No Overrun Braking - D2

No Engine Braking - D2

No Engine Braking - D2

No Second Gear Engine Braking - D2

No Second Gear Engine Braking - D2

No First Gear - D3

No First Gear - D3

No Second Gear - D3

No Second Gear - D3

No Third Gear - D3

No Third Gear - D3

No Overrun Braking - D3

No Overrun Braking - D3

No Engine Braking - D3

No Engine Braking - D3

No First Gear - D4

No First Gear - D4

First Gear Only - D4

First Gear Only - D4

First and Second Gear Only - D4

First and Second Gear Only - D4

Second Gear Only - D4

Second Gear Only - D4

Second and Third Gear Only - D4

Second and Third Gear Only - D4

First and Fourth Gear Only - D4

First and Fourth Gear Only - D4

Third and Fourth Gear Only - D4

Third and Fourth Gear Only - D4

No Second Gear - D4

No Second Gear - D4

No Third Gear - D4

No Third Gear - D4

No Fourth Gear - D4

No Fourth Gear - D4

Converter Ballooning

Converter Ballooning

Engine Stall

Engine Stall

Oil Out the Vent Tube

Oil Out the Vent Tube

Second Gear Starts

Second Gear Starts

Third Gear Starts

Third Gear Starts

Fourth Gear Starts

Fourth Gear Starts

Erratic Shift Quality

Erratic Shift Quality

Transmission Slips

Transmission Slips

Case Extension Bearing/Seal Failed

Case Extension Bearing/Seal Failed

Inaccurate Shift Points

Inaccurate Shift Points

Harsh Shifts

Harsh Shifts

Harsh Shift D to R

Harsh Shift D to R

Harsh Shift 3 to 4

Harsh Shift 3 to 4

Harsh Shift 4 to 3

Harsh Shift 4 to 3

Harsh Shift D4 to D3, D2, or D1

Harsh Shift D4 to D3, D2, or D1

Soft Shifts

Soft Shifts

Soft Shift into R

Soft Shift into R

Soft Shift R to D

Soft Shift R to D

Soft Shift 2 to 1

Soft Shift 2 to 1

Soft Shift 2 to 3

Soft Shift 2 to 3

Soft Shift 3 to 2

Soft Shift 3 to 2

Soft Shift D3 to D2

Soft Shift D3 to D2

Delayed Shift 1 to 2

Delayed Shift 1 to 2

No D2 to D1

No D2 to D1

No D3 to D2

No D3 to D2