4T65EV Transmission
Incorrect gear ratio
Check the quality of the transmission oil
Note! The transmission fluid quality is extremely important for transmission function. Therefore it is imperative that this is correct.
- Ignition off.
Check the transmission oil quality. Take a sample using the dip stick.
- Check if the transmission fluid is dark and smells burnt
- Check the transmission oil and filter. Check for abnormal large amounts of particles in the oil. If the transmission oil contains impurities, e.g., metal filings, the cause is some form of wear in the transmission and may lead to components jamming and failing. If there are a lot of contaminants or larger particles, there may be an internal fault in the transmission.
- Check if there is oil or an oil film in the expansion tank. Oil in the expansion tank indicates leakage from the transmission oil cooler which is positioned in the cooler unit.
Note! The transmission oil is red and must not be confused with black engine oil.
- If the transmission fluid is cloudy or pink, it is contaminated with coolant. In such cases the transmission must be replaced.
When replacing the transmission, the cooler unit, including the additional cooler must be replaced if installed. Replace the hoses between the cooler and the transmission.
Select an alternative
1. The fluid contains water
2. The oil was dark and smelled burnt
3. Glycol in the transmission fluid.
4. No fault detected.
1 - Replacing the transmission
2 - Replacing the transmission
3 - Checking for coolant in oil
4 - Checking the oil level in the transmission
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Checking the oil level in the transmission
Checking the oil level in the transmission
Check the transmission oil level
Note! The transmission fluid level is extremely important for transmission function. Therefore it is imperative that it is correct. In addition the oil level is dependent on oil temperature.
- Start the car
- Read off the oil temperature.
When checking the transmission fluid level, the temperature must be 80-90°C.
At the correct temperature, the oil level should be between "Min hot" and "Max hot".
Oil level
- Too high:Drain the transmission fluid to the correct level
- Too low:Check the transmission for leakage.
Remedy as necessary.
Other information:
- To check and adjust the oil level, see Oil level, checking Checking Oil Level.
Was the transmission fluid level correct?
OK - Checking diagnostic trouble codes (DTCs)
NOT OK - Resetting the oil quality counter
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Checking diagnostic trouble codes (DTCs)
- Ignition on
- Read off diagnostic trouble codes (DTCs).
If any other diagnostic trouble codes (DTCs) than TCM-0027, TCM-0028, TCM-0029, TCM-002A or TCM-002B are stored, these must be fault-traced after this fault-tracing is completed.
Continue - Checking diagnostic trouble codes (DTCs)
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Checking diagnostic trouble codes (DTCs)
Erasing diagnostic trouble codes (DTCs)
- Ignition off
- Wait for two minutes to allow time for the diagnostic trouble codes (DTCs) to be stored in the control module memory
- Ignition on
- Erase diagnostic trouble codes (DTCs).
Continue - Check the diagnostics number
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Check the diagnostics number
Checking the software
Note! To carry out fault-tracing, the transmission control module (TCM) must be programmed with specific software.
- Ignition on
- Read off the control module diagnostic number.
Check the read off diagnostic number against the diagnostic numbers given in the center table.
If the diagnostic number is included in the table, the control module must be programmed with the latest software.
See the technical journal for information about the most recent software.
Continue - Test driving
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Test driving
Note! Test drive the car according to the driving schedule below to check whether the fault is still active. The test drive is compiled in order to create the conditions in which the diagnostic trouble code (DTC) will be stored again if the fault is active. The TEST MODE function can be used to provoke any diagnostic trouble codes (DTC). The function reduces the conditions for how quickly diagnostic trouble codes (DTCs) are stored in the control module and the test drive becomes easier.
- Ignition on
- Activate TEST MODE
- Test drive the car according to the driving schedule below.
Hint: Test drive the car and try to regenerate the fault.
Move the gear selector during the test drive to the gear position indicated in the table for each diagnostic trouble code (DTC) and transmission. Follow the criteria below.
Criteria for diagnostic trouble code (DTC):
- No shifting (automatic or manual) must take place for approximately 20 seconds
- The gear selector must not be moved out of position
- Speed must be in excess of 30 km/h
- Positive engine torque (no engine braking)
- Transmission fluid temperature above than 20°C.
Continue - Checking diagnostic trouble codes (DTCs)
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Checking diagnostic trouble codes (DTCs)
- Ignition on
- Read off diagnostic trouble codes (DTCs).
Were any of the diagnostic trouble codes (DTCs) TCM-0027, 0028, 0029, 002A, 002B stored?
DTC - Checking the transmission output speed sensor signal
NO DTC - Fault-tracing information
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Checking the transmission output speed sensor signal
- Ignition off
- Check the control module and speed sensor connectors. Check for contact resistance and oxidation. Remedy if necessary
- Raise the car so that the drive wheels are clear of the ground
- Start the engine. Allow the engine to idle
- If the car has STC or DSTC, these functions must be disengaged. Press in the STC/DSTC button on the center console. Hold the button in for at least two seconds
- Move the gear selector to position D so that the drive wheels begin to rotate
- Read off the transmission speed (output speed).
Depress the accelerator pedal (AP) and check that the speed is updated.
Note! Ensure that the wheels are not rotating when the gear selector is moved.
Note! Diagnostic trouble codes (DTCs) may be stored in the ABS system when the rear wheels are stationary and the front wheels rotate. Erase any diagnostic trouble codes (DTCs) stored in the ABS system after fault-tracing.
Other information:
- To access the control module connector, see Connecting the breakout box, 4T65EV-GT Connecting the Breakout Box
- To access the transmission output speed sensor connector, see Output speed sensor gearbox, replacing Transmission Output Speed Sensor, Replacing
- Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault
Was the speed updated?
Yes - Checking the transmission input speed sensor signal
No - Checking the wiring and component
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Checking the wiring and component
- Ignition off.
Check the power supply cable between the transmission control module (TCM) terminal #A57 (#A57) and transmission output speed sensor terminal #1. Check for an open-circuit according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault. Check for a short-circuit to ground according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault. Check for a short-circuit to supply voltage according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.
Check the signal cable transmission control module (TCM) terminal #A39 (#A39) and transmission output speed sensor terminal #2. Check for an open-circuit, a short-circuit to ground and for a short-circuit to supply voltage.
Hint: With the control module connected, the ignition on and a voltmeter connected between transmission output speed sensor terminals #1 and #2 (control module side), the voltage must be approximately 1-3 V below Ubat.
Remedy as necessary.
Other information:
- To connect the breakout box, see Connecting the breakout box, 4T65EV-GT Connecting the Breakout Box
- To disconnect the transmission control module (TCM), see Transmission control module (TCM), replacing, B5254T2, AW50/51 AWD, B5254T2, AW55-50/51SN Service and Repair
- To check or replace the transmission output speed sensor, see Output speed sensor gearbox, replacing Transmission Output Speed Sensor, Replacing
- For information about signals, see Signal specification, 4T65EV-GT Signal Specification
- Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault
Was a fault detected?
Yes - Verification
No - Checking the transmission input speed sensor signal
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Checking the transmission input speed sensor signal
- Ignition off
- Check the control module and transmission input speed sensor connectors. Check for contact resistance and oxidation. Remedy if necessary
- Start the engine. Allow the engine to idle
- Read off the transmission input speed.
Depress the accelerator pedal (AP) and check that the speed is updated. Compare with the engine speed (RPM).
Other information:
- Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault
Was the transmission speed updated?
Yes - Replacing the transmission
No - Checking wiring and sensors
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Checking wiring and sensors
- Ignition off
- Connect the breakout box to the transmission
- Disconnect the control module
- Disconnect the transmission connector
- Connect adapter 951 1505 Adapter 20 pin 951 1505 Adapter 20 Pin and breakout box 951 1428 Breakout box 951 1428 Breakout Box to the transmission connector (control module side).
Check the power supply cable between the transmission control module (TCM) terminal #A59 (#A59) and transmission connector terminal #S (#A16). Check for an open-circuit, a short-circuit to ground and for a short-circuit to supply voltage.
Check the signal cable between transmission control module (TCM) terminal #A41 (#A41) and transmission connector terminal #V (#A19). Check for an open-circuit, a short-circuit to ground and for a short-circuit to supply voltage.
Hint: With the transmission control module (TCM) connected, the ignition on and a voltmeter connected between transmission connector terminals #S (#A16) and #V (#A19) (control module side), the voltage must be approximately 1-3 V below Ubat.
Remedy as necessary.
Other information:
- To connect the breakout box, see Connecting the breakout box, 4T65EV-GT Connecting the Breakout Box
- To disconnect the transmission control module (TCM), see Transmission control module (TCM), replacing, B5254T2, AW50/51 AWD, B5254T2, AW55-50/51SN Service and Repair
- To disconnect the transmission connector, see Connecting the breakout box, GM automatic transmissions, 4T65EV-GT Connecting the Breakout Box, GM Automatic Transmissions
- For information about signals, see Signal specification, 4T65EV-GT Signal Specification
- For information about signals to the transmission connector, see Signal description. Connector 4T65 EV/EV-GT, 4T65EV-GT Connector 4T65 EV/EV-GT
- Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault
Was a fault detected?
Yes - Verification
No - Checking the wiring and component
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Checking the wiring and component
- Ignition off
- Open the transmission control system.
Check the cable for power supply between transmission connector terminal #S (#A16) and transmission input speed sensor connector terminal #A. Check for an open-circuit, a short-circuit to ground and for a short-circuit to supply voltage.
Check the signal cable between transmission connector terminal #V (terminal #A19) and transmission input speed sensor connector terminal #B. Check for an open-circuit, a short-circuit to ground and a short-circuit to supply voltage.
Remedy as necessary.
Other information:
- To open the transmission control system, see Side cover transmission, replacing Side Cover Transmission, Replacing
- To connect the breakout box to the transmission connector, see Connecting the breakout box, GM automatic transmissions, 4T65EV-GT Connecting the Breakout Box, GM Automatic Transmissions
- To replace the transmission speed sensor, see Input speed sensor transmission, replacing Transmission Input Speed Sensor, Replacing
- To replace the cable harness, see Wiring harness / oil temperature sensor, replacing Removal and Replacement
- For information about signals, see Signal specification, 4T65EV-GT Signal Specification
- Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault
Continue - Resetting the adaptation and oil quality counter
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Replacing the transmission
Fault-tracing indicates a fault in the transmission. Replace the transmission.
Also replace the radiator and coolant hoses if there is water in the transmission fluid.
Other information:
- To remove the transmission, see Gearbox, removing Gearbox, Removing
- To install the transmission, see Gearbox, installing Gearbox, Installing.
Continue - Resetting the adaptation and oil quality counter
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Resetting the oil quality counter
Resetting Transmission fluid change counter
Hint: The transmission control module (TCM) has a counter for the oil quality. The counter counts up if the transmission is exposed to too high a load or an ambient temperature that is too high. If the counter is not reset when the oil is drained or changed, there is a risk that a diagnostic trouble code (DTC) will be stored in faulty circumstances. Therefore it is important that the "Transmission oil change" counter is reset.
Note! This applies only when the transmission fluid is changed and when the fluid is changed when repairs are carried out to the transmission temperature sensor.
- Ignition on.
Reset the counter by clicking on the VCT 2000 symbol.
Continue - Verification
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Resetting the adaptation and oil quality counter
Resetting the adaptation
Resetting adaptation and the counter for "Transmission oil change"
Hint: The transmission has torque controlled adaptive pressure control. Pressure control means that the transmission regulates the pressure itself during each gear shift. This avoids harsh gear shifting. Each gear shift is evaluated by the control module and stored in the memory. This allows for compensation for wear and tear in the transmission and clutch. It is important that the adaptation in the memory is reset after the transmission has been repaired. This is to ensure normal operation. The oil is replaced during repair; the "Transmission oil change" counter must be reset. If the counter is not reset when the fluid is drained and replaced, there is a risk that a diagnostic trouble code (DTC) will be stored in incorrect circumstances.
Note! This applies only if the transmission or one of the components in the transmission have been replaced.
- Ignition on.
Click on the VCT2000 symbol to reset the adaptation and counter.
Continue - Verification
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Fault-tracing information
The fault-tracing indicates that the control module has previously detected a fault but that the fault is no longer active.
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Verification
Checking diagnostic trouble codes (DTCs)
DTC - Fault-tracing information
NO DTC - FAULT FOUND
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Fault-tracing information
Information
Fault-tracing information
The fault should have been detected and remedied. As this is not the case fault-tracing has failed.
Exit fault-tracing for this diagnostic trouble code (DTC) or make another attempt.
Do you want to exit fault-tracing?
Yes - Exit Fault-Tracing
No - Attempt New Test
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Checking for coolant in oil
This fault may be due to coolant that has leaked into the transaxle.
Inspect according to: Checking for coolant in the oil, AW55-50/51SN, AW50/51 AWD, 4T65EV-GT Checking For Coolant In the Oil
If coolant is detected in the transaxle oil, the transaxle, radiator and hoses between the radiator and transaxle must be replaced.
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Information
Information
Fault-tracing information
In case of this defect, troubleshooting is not followed by verification.
The information can be displayed again or the fault-tracing for this fault can be interrupted.
Do you want to view the information again?
Yes - Attempt New Test
No - Exit fault-tracing
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Checking for coolant in oil
This fault may be due to coolant that has leaked into the transaxle.
Inspect according to: Checking for coolant in the oil, AW55-50/51SN, AW50/51 AWD, 4T65EV-GT Checking For Coolant In the Oil
If coolant is detected in the transaxle oil, the transaxle, radiator and hoses between the radiator and transaxle must be replaced.
Other information
- Transaxle, removing Gearbox, Removing
- Transmission, installing Gearbox, Installing
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