Transmission Cooling System Cadillac ELR I

Fastener Tightening Specifications

Fastener Tightening Specifications

Diagnostic Instructions

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/elr/i-2013-2015/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/elr/i-2013-2015/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/elr/i-2013-2015/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Diagnostic Fault Information

Circuit/System Description

The primary source of heat in the 4ET50 transmission is the drive motors. The drive motors are cooled by the transmission fluid. Hot fluid exits the drive motors and flows to the transmission oil cooler through the transmission cooler supply line and thermal bypass valve. The thermal bypass valve assembly is located near the lower left side of the radiator. The cooled fluid returns to the transmission through the transmission fluid cooler pipe assembly and cools the control solenoid assembly. The transmission fluid temperature sensor is located in the control solenoid assembly and is not serviced separately. The Transmission Fluid Temperature parameter on the scan tool should rise steadily to a normal operating temperature, and then stabilize.

The thermal bypass valve is mechanically operated, based on the oil temperature of the transmission in order to maintain optimum transmission operating efficiency. The valve has an activating temperature of 82°C (176°F), with the range to move being 78-83°C (172-181°F). The full open temperature is 96°C (205°F). The thermal bypass valve assembly begins to open at 82°C (176°F) for optimum transmission operation and fuel economy. The valve has a typical oil flow rate of 9-10 lpm (2.4-2.6 gpm).

Cold Mode

82°C (176°F) and below the thermal bypass valve bypasses the oil going to the cooler and sends the fluid back to the transmission.

Mixing Mode

82-96°C (176-205°F) the thermal bypass valve is in mixing mode - some of the fluid flows back to the trans and some flows through the transmission oil cooler.

Hot Mode

Above 96°C (205°F) The thermal bypass valve is fully open and transmission oil flows through the cooler then back to the transmission.

Reference Information

Schematic Reference

1. «Automatic Transmission Controls Schematics»(/cadillac/elr/i-2013-2015/remont/automatic-trans/#automatic-transmission-4et50-schematic-wiring-diagrams)
2. «Park Engine Off»(/cadillac/elr/i-2013-2015/remont/automatic-trans/#automatic-transmission-4et50-description-and-operation__park-engine-off)
3. «Park Engine On»(/cadillac/elr/i-2013-2015/remont/automatic-trans/#automatic-transmission-4et50-description-and-operation__park-engine-on)
4. «Fluid Passages»(/cadillac/elr/i-2013-2015/remont/automatic-trans/#automatic-transmission-4et50-description-and-operation)

Description and Operation

1. «Transmission General Description»(/cadillac/elr/i-2013-2015/remont/automatic-trans/#automatic-transmission-4et50-description-and-operation__transmission-general-description)
2. «Transmission Indicators and Messages»(/cadillac/elr/i-2013-2015/remont/automatic-trans/#automatic-transmission-4et50-description-and-operation__transmission-indicators-and-messages)

Scan Tool Reference

Control Module References for scan tool information

Special Tools

1. DT 24731 Tempil Stick
2. DT 45096 Transmission Oil Cooler System Flush and Flow Test Tool

For equivalent regional tools, refer to Special Tools .

Component Testing

1. Perform the «Fluid Leak Diagnosis»(/cadillac/elr/i-2013-2015/remont/automatic-trans/#automatic-transmission-4et50-diagnostic-information-and-procedures) .
2. Verify airflow through the radiator is not obstructed. Refer to «Radiator Cleaning»(/cadillac/elr/i-2013-2015/remont/cooling-system-mechanical/#engine-cooling-system__radiator-cleaning) .
3. Perform the «Transmission Fluid Level and Condition Check»(/cadillac/elr/i-2013-2015/remont/automatic-trans/#automatic-transmission-4et50-diagnostic-information-and-procedures__transmission-fluid-level-and-condition-check) procedure.
4. Perform the «Line Pressure Check»(/cadillac/elr/i-2013-2015/remont/automatic-trans/#automatic-transmission-4et50-diagnostic-information-and-procedures__line-pressure-check) procedure.
5. Perform the «Main Fluid Pump Pressure High or Low»(/cadillac/elr/i-2013-2015/remont/automatic-trans/#automatic-transmission-4et50-diagnostic-information-and-procedures__main-fluid-pump-pressure-high-or) procedure.
6. Perform the «Transmission Fluid Cooler Flushing and Flow Test»(/cadillac/elr/i-2013-2015/remont/automatic-trans/#transmission-cooling-system__transmission-fluid-cooler-flushing-and-flow) .
7. With a hand held or infra red thermometer or DT 24731 tempil stick , test for the transmission cooler supply line thermal bypass valve assembly opening at 96°C (205°F). The transmission cooler supply line temperature should be higher on the transmission side of the thermal bypass valve assembly than the cooler side until 96°C (205°F) is reached. If the thermal bypass valve tests stuck closed Replace the thermal bypass valve assembly. If the thermal bypass valve tests normal Inspect the transmission oil passages for a blockage. If passages are blocked Repair as necessary. If passages are not blocked
8. All OK

Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.

1. «Transmission Fluid Cooler Replacement»(/cadillac/elr/i-2013-2015/remont/automatic-trans/#transmission-cooling-system)
2. «Transmission Fluid Cooler Thermal Bypass Valve Replacement»(/cadillac/elr/i-2013-2015/remont/automatic-trans/#transmission-cooling-system)
3. «Transmission Fluid Cooler Inlet Pipe Replacement»(/cadillac/elr/i-2013-2015/remont/automatic-trans/#transmission-cooling-system)
4. «Transmission Fluid Cooler Outlet Pipe Replacement»(/cadillac/elr/i-2013-2015/remont/automatic-trans/#transmission-cooling-system)

Transmission Fluid Cooler Flushing and Flow Test

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

Note. Use the DT 45096 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®VI 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

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

Special Tools

1. DT 45096 Transmission Oil Cooling System Flush and Flow Test Tool
2. DT 45096-50 Transmission Cooler Flush Adapter
3. DT 45096-55 Transmission Cooler Flush Adapter
4. Shop air supply with water/oil filters, regulator and pressure gauge - minimum 90 psi
5. Eye protection
6. Rubber gloves

For equivalent regional tools, refer to Special Tools .

Machine Set-up

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

Determine Minimum Flow Rate

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

Minimum Flow Rate in Gallons Per Minute (gpm)

Scheme 67

1. Remove the fluid cooler bypass valve. Refer to «Transmission Fluid Cooler Thermal Bypass Valve Replacement»(/cadillac/elr/i-2013-2015/remont/automatic-trans/#transmission-cooling-system) .
2. Install the DT 45096-55 cooler flush adapter.

Back Flush Procedure

1. Connect the DT 45096-50 flush adapter (1) to the vehicle transmission oil cooler supply and return lines at the transmission.
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.

Forward Flush

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.

Flow Test

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

Code Recording Procedure

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

Scheme 68

1. Turn the main function switch (2) to the IDLE position and allow the supply vessel pressure to dissipate.
2. Turn the main power switch (1) to the OFF position.
3. Disconnect the supply and waste hoses and the 12-volt power source from the vehicle.
4. Disconnect the air supply hose from DT 45096 flush and flow test tool.
5. Remove DT 45096-55 cooler flush adapter and install the fluid cooler bypass valve.
6. Attach cooler lines to the transmission.
7. Dispose of the waste ATF in accordance with all applicable federal, state, and local requirements.

Removal Procedure

1. Remove the air conditioning condenser. Refer to «Air Conditioning Condenser Replacement»(/cadillac/elr/i-2013-2015/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .
2. Remove the transmission fluid cooler thermal bypass valve. Refer to «Transmission Fluid Cooler Thermal Bypass Valve Replacement»(/cadillac/elr/i-2013-2015/remont/automatic-trans/#transmission-cooling-system) .
3. Remove the air conditioning condenser bracket (1) from the radiator.
4. Remove the transmission fluid auxiliary cooler (1) from the air conditioning condenser bracket.

Installation Procedure

1. Install the transmission fluid auxiliary cooler (1) to the air conditioning condenser bracket.
2. Install the air conditioning condenser bracket (1) to the radiator.
3. Install the transmission fluid cooler thermal bypass valve. Refer to «Transmission Fluid Cooler Thermal Bypass Valve Replacement»(/cadillac/elr/i-2013-2015/remont/automatic-trans/#transmission-cooling-system) .
4. Install the air conditioning condenser. Refer to «Air Conditioning Condenser Replacement»(/cadillac/elr/i-2013-2015/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .

Scheme 69

Transmission Fluid Cooler Thermal Bypass Valve Replacement

1. Place a drain pan under vehicle.
2. Remove the transmission fluid cooler thermal bypass valve. Refer to «Transmission Fluid Cooler Thermal Bypass Valve Replacement»(/cadillac/elr/i-2013-2015/remont/automatic-trans/#transmission-cooling-system) .
3. Remove the oil cooler fitting (1) from the radiator.

1. Inspect the new O-ring seals for cracks, cuts or damage. Replace if necessary.
2. Install the oil cooler fitting (1) to the radiator and tighten to 38 (28 lb ft).
3. Install the transmission fluid cooler thermal bypass valve. Refer to «Transmission Fluid Cooler Thermal Bypass Valve Replacement»(/cadillac/elr/i-2013-2015/remont/automatic-trans/#transmission-cooling-system) .
4. Adjust the transmission fluid level.
5. Inspect for fluid leaks.

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

Special Tools

GE-41623 Cooler Quick Connect Tool

For equivalent regional tools, refer to Special Tools .

1. Install the GE-41623 cooler quick connect tool onto the transmission oil cooler (TOC) pipe.
2. Slide the GE-41623 cooler quick connect tool toward the TOC pipe fitting.
3. Connect the GE-41623 cooler quick connect tool onto the TOC pipe fitting.
4. Rotate the GE-41623 cooler quick connect tool until the retainer clip (1) rises above the fitting retainer seat.
5. Pull back on the TOC pipe to disengage the pipe from the TOC pipe fitting.
6. Remove the GE-41623 cooler quick connect tool from the TOC pipe.

1. Install the TOC pipe into the TOC pipe fitting. A distinct snap should be heard or felt when assembling the TOC pipe to the fitting.
2. To ensure the cooler line is properly installed, give the cooler pipe a gentle pull.

Scheme 70

Transmission Fluid Cooler Inlet Pipe Replacement

Scheme 71

Transmission Fluid Cooler Outlet Pipe Replacement

Special Tools

Illustration Tool Number/ Description DT-41623-B J 41623-B KM-J-41623-B 87 92 806 8792806 Cooler Quick Connect Tool GE 24731 J 24731 Tempil Stick DT 45096 J 45096 Transmission Oil Cooling System Flush and Flow Test Tool DT 45096-50 J 45096-50 Transmission Cooler Flush Adapter DT 45096-55 Transmission Cooler Flush Adapter

Scheme 72

Scheme 73

Scheme 74

Scheme 75

See also:
• Diagnostic System Check - Vehicle
• Strategy Based Diagnosis
• Diagnostic Procedure Instructions
• Engine Overheating
• Automatic Transmission Controls Schematics
• Park Engine Off
• Park Engine On
• Fluid Passages
• Transmission General Description
• Transmission Indicators and Messages
• Control Module References
• Special Tools
• Fluid Leak Diagnosis
• Radiator Cleaning
• Transmission Fluid Level and Condition Check
• Line Pressure Check
• Main Fluid Pump Pressure High or Low
• Diagnostic Repair Verification
• Air Conditioning Condenser Replacement
• Lifting and Jacking the Vehicle
• Front Bumper Fascia Removal and Installation
• Fastener Caution
• High Voltage Disabling
• Drive Motor Generator Power Inverter Module Replacement
• Front Wheelhouse Liner Replacement
• Transmission Fluid Cooler Flushing and Flow Test
• Transmission Fluid Cooler Replacement
• Transmission Fluid Cooler Hose/Pipe Quick-Connect Fitting Disconnection and Connection