Automatic Transmission - 4L60-E/4L65-E (Service & Replacement): Maintenance Chevrolet Suburban X

Cooler Flow Check and Flushing Steps

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

Tools Required

1. J 35944-200 Cooler Flushing Adapter
2. J 45096 Transmission Oil Cooling System Flush and Flow Test Tool
3. Shop air supply with water/oil filters, regulator and pressure gage - minimum 90 psi
4. Eye protection
5. Rubber gloves

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1. Verify that the main power switch (1) is in the OFF position.
2. Place the main function switch (2) in the IDLE position.
3. Connect J 45096 to the vehicle 12V DC power source by connecting the red battery clip to the positive, +, battery post on the vehicle and connect the negative lead to a known good chassis ground.
4. Turn the main power switch to the ON position. NOTE: Do not overfill the supply vessel. Damage to the unit may result. To verify the fluid level, view the LCD screen display while filling the unit, to ensure the fluid level does not exceed 30 L (32 qt).
5. Fill the supply tank with DEXRON®III/Mercon®, or equivalent, through the fill port.
6. Reinstall and tighten the fill cap.
7. Connect a shop air supply hose to the quick-disconnect on the rear panel marked SUPPLY AIR.

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

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1. Connect the J 45096 adapters (1) to the vehicle's transmission oil cooler supply and return lines at the transmission, may require J 35944-200.
2. Connect the black supply hose (1) to the return line, top connector of the transmission, and the clear waste hose (2) to the feed line, bottom connector of the transmission, to the vehicle cooler lines. This is the reverse flow - backflush direction.
3. Turn the main function switch to the FLUSH position. Allow the machine to operate for 30 seconds.
4. Turn the main function switch to the IDLE position and allow the supply vessel pressure to dissipate.

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1. Disconnect the supply and waste hoses from the vehicle cooler lines. Reverse the supply and waste hoses to provide a normal flow direction.
2. Turn the main function switch to the FLUSH position and allow machine to operate for 30 seconds.

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Important: If the flow rate is less than 0.5 gpm, the LCD displays an error message. Refer to the Troubleshooting section of the operation manual.

1. Turn the main function switch to the FLOW position and allow the oil to flow for 15 seconds. Observe and note the flow rate; this is the TESTED flow rate.
2. Compare the TESTED flow rate to the MINIMUM flow rate information previously recorded. If the TESTED flow rate is equal to or greater than the MINIMUM flow rate recorded, the oil cooling system is functioning properly. Perform Code Recording Procedure. If the TESTED flow rate is less than the MINIMUM flow rate previously recorded, repeat the back flush and forward flush procedures.
3. If the TESTED flow rate is less than the MINIMUM flow rate after the second test, perform Code Recording Procedure. 3.1. Replace the transmission oil cooler. 3.2. Reconnect supply and waste hoses to the cooler lines in the normal flow direction. Perform Flow Test. 3.3. Perform Code Recording Procedure.

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1. Turn the main function switch to the CODE position. Important: If power is interrupted prior to the recording of the seven-character code, the code will be lost and the flow rate test will need to be repeated. The flow test must run for a minimum of 8-10 seconds and be above 0.5 gpm for a code to be generated.
2. Record TESTED flow rate, temperature, cycle and seven-character flow code information on repair order.

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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. NOTE: A small amount of water may drain from the bottom of the unit when the air supply is disconnected. This is a normal operation of the built-in water separator.
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.

1. Tools Required
2. Preparation
3. Back Flush
4. Forward Flush
5. Flow Check
6. Clean-up

Tools Required

1. J 35944-A Transmission Oil Cooler Flusher
2. J 35944-22 Transmission Oil Cooler Flushing Fluid
3. J 35944-200 Cooler Flushing Adapter
4. Measuring cup
5. Funnel
6. Water supply, hot water recommended
7. Water hose, at least 16 mm (5/8 in) ID
8. Shop air supply, with water/oil filters, regulator and pressure gage
9. Air chuck, with clip if available
10. Oil drain container
11. Pail with lid 19 L (5 gallon)
12. Eye protection
13. Rubber gloves

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1. During the installation of the repaired or replacement transmission, do not connect the oil cooler pipes. NOTE: Do not use solutions that contain alcohol or glycol. Use of solutions that contain alcohol or glycol may damage the J 35944-A, oil cooler components and/or transmission components. Important: The J 35944-22 is environmentally safe, yet powerful enough to cut through transmission fluid to dislodge any contaminants from the cooler. The safety precautions on the label, regarding potential skin and eye irritations associated with prolonged exposure, are typical precautions that apply to many similar cleaning solutions. It should be noted that according to GM, use of other non-approved fluids for cooler flushing can have an adverse reaction to the seals inside the transmission.
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.

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1. Inspect the transmission oil cooler pipes for kinks or damage. Repair as necessary.
2. Connect the J 35944-A to the oil cooler feed bottom connector. Use the J 35944-200, if required.
3. Clip the discharge hose (2) onto the oil drain container.
4. 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 top connector oil cooler return pipe. Use the J 35944-200, if required.
5. 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.
6. 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. Important: Flushing for approximately 2 minutes in each cooler line direction will result in a total of about 8-10 gallons of waste fluid. This mixture of water and flushing fluid is to be captured in a bucket or similar container.
7. 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.
8. 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.
9. Release the trigger (1) and turn the J 35944-A water supply valve (3) to the OFF position.

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1. 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.
2. Repeat Step 6 and 7 of the Back Flush.
3. Release the trigger (1) of the J 35944-A and allow water only to rinse the oil cooler and pipes for 1 minute.
4. Turn the J 35944-A water supply valve (3) to the OFF position and turn OFF the water supply at the faucet.
5. 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.

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Important: The Flow Test must be performed after the flush to ensure that all flushing solution and water is removed from the oil cooling system.

1. Disconnect the hose from the oil cooler pipe. Connect the oil cooler feed pipe, bottom connector, to the transmission for normal flow.
2. Clip the discharge hose (1) to an empty oil container.
3. Confirm the transmission is filled with automatic transmission fluid. Refer to Fluid Capacity Specifications, See «Fluid Capacity Specification»(ref-180351-S34601227462005092800000) for the correct automatic transmission fluid capacity.
4. 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.
5. If the fluid flow meets or exceeds 1.9 L (2 quarts) in 30 seconds, connect the oil cooler feed pipe to the bottom connector on the transmission.
6. If fluid flow is less than 1.9 L (2 qt) in 30 seconds, perform the following diagnosis: 6.1. Disconnect the J 35944-A discharge hose (1) from the oil cooler return pipe. 6.2. Disconnect the oil cooler feed pipe at the radiator. 6.3. Connect the J 35944-A discharge hose (1) to the oil cooler feed pipe, radiator end. 6.4. Clip the discharge hose (1) onto the oil drain container. 6.5. 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.
7. If the amount of transmission fluid flow remains less than 1.9 L (2 qt) in 30 seconds, inspect the oil cooler feed pipe, bottom connector, for restrictions or damage. If no condition is found with the feed pipe, bottom connector, inspect the transmission.

Automatic Transmission Fluid Temperature Sensor

The automatic transmission fluid temperature (TFT) sensor is part of the automatic transmission fluid pressure (TFP) manual valve position switch. The TFT sensor is a resistor, or thermistor, which changes value based on temperature. The sensor has a negative-temperature coefficient. This means that as the temperature increases, the resistance decreases and as the temperature decreases, the resistance increases.

The PCM supplies a 5-volt reference signal to the TFT sensor and measures the voltage drop in the circuit. When the transmission fluid is cold, the sensor resistance is high and the PCM detects high signal voltage. As the fluid temperature warms to a normal operating temperature, the resistance becomes less and the signal voltage decreases. Refer to TFT Sensor Specifications for a complete comparison of sensor resistance, temperature and signal voltage.

The PCM uses the TFT sensor information to control shift quality and TCC application.

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The transmission range (TR) switch is part of the park/neutral position (PNP) and backup 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.

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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.

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The transmission electrical connector is an important part of the transmission operating system. Any interference with the electrical connection can cause the transmission to set diagnostic trouble codes or affect proper operation.

The following items can affect the electrical connection

1. Bent pins in the connector from rough handling during connection and disconnection
2. Wires backing away from the pins or coming uncrimped, in either the internal or the external wiring harness
3. Dirt contamination entering the connector when disconnected
4. Pins in the internal wiring connector backing out of the connector or pushed out of the connector during reconnection
5. Transmission fluid leaking into the connector, wicking up into the external wiring harness and degrading the wire insulation
6. Moisture intrusion in the connector
7. Low pin retention in the external connector from excessive connection and disconnection of the wiring connector assembly
8. Pin corrosion from contamination
9. Damaged connector assembly

Remember the following points

1. In order to remove the connector, squeeze the two tabs toward each other and pull straight up without pulling by the wires.
2. Limit twisting or wiggling the connector during removal. Bent pins can occur.
3. Do not pry the connector off with a screwdriver or other tool.
4. Visually inspect the seals to ensure that they are not damaged during handling.
5. In order to reinstall the external wiring connector, first orient the pins by lining up the arrows on each half of the connector. Push the connector straight down into the transmission without twisting or angling the mating parts.
6. The connector should click into place with a positive feel and/or noise.
7. Whenever the transmission external wiring connector is disconnected from the internal harness and the engine is operating, DTCs will set. Clear these DTCs after reconnecting the external connector.

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