4T65EV Transmission
Signal too high
Checking the function of the oil temperature sensor
- Ignition on
- Read off the oil temperature.
Check that the temperature is within its permitted range.
Compare with the transmission temperature.
Is the transmission temperature within its permitted range?
Yes - Intermittent fault
No - Checking transmission fluid temperature sensor
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Checking transmission fluid temperature sensor
- Ignition off
- Check the control module and transmission connectors. Check for contact resistance and oxidation
- Reconnect the control module and transmission connectors
- Ignition on
- Read off the oil temperature.
Check that the temperature is within its permitted range.
Compare with the transmission temperature.
If the transmission temperature is within its permitted range, the cause of the fault was contact resistance or oxidation in the control module or transmission connector.
Other information
- To disconnect the control module, see Transmission control module (TCM), replacing, B5254T2, AW50/51 AWD, B5254T2, AW55-50/51SN Service and Repair
- 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
- Checking wiring and terminals Checking Wiring And Terminals
Was the transmission temperature within its permitted range?
Yes - Verification
No - Checking the temperature sensor
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Checking the temperature sensor
- Ignition off
- Disconnect the transmission connector
- Connect adapter951 1505 Adapter 20 pin 951 1505 Adapter 20 Pin and981 3190 Replaced by 9511428 981 3190 Replaced by 951 1428 to the transmission connector (transmission side)
- Connect an ohmmeter between terminals #L (terminal #A11) and #M (terminal #A12).
The resistance must be 3.4-3.6 kohms at 20 °C.
Other information
- 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
- For information about signals, see Signal specification, 4T65EV-GT Signal Specification
- For information about the resistance values, see Component resistance values, 4T65EV-GT Component Resistance Values
- For information about the resistance values, see Component resistance values, 4T65EV-GT Component Resistance Values.
Was the resistance OK?
Yes - Checking the wiring
No - Checking the wiring and component
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Checking the wiring
- Breakout box connected to the control module
- Breakout box connected to the transmission connector.
Check the cable between control module terminal #37 (#A37) and transmission connector (control module side) terminal #L (#A11). Check for an open-circuit. Check for a short-circuit to supply voltage.
Check the cable between control module terminal #55 (#A55) and transmission connector (control module side) terminal #M (#A12). Check for an open-circuit. Check for a short-circuit to supply voltage.
Remedy as necessary.
Other information
- To connect the breakout box, see Connecting the breakout box, 4T65EV-GT Connecting the Breakout Box
- 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
- For information about signals, see Signal specification, 4T65EV-GT Signal Specification
- Checking wiring and terminals Checking Wiring And Terminals
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 between transmission terminal #L (#A11) and temperature sensor terminal #A. Check for an open-circuit. Check for a short-circuit to supply voltage.
Check the cable between transmission terminal #M (#A12) and temperature sensor terminal #B. Check for an open-circuit. Check for a short-circuit to supply voltage.
Hint: Check the temperature sensor by measuring the resistance between temperature sensor connector terminals #A and #B. The resistance must be between 3.5-3.6 kohms at 20° C.
Remedy as necessary.
Other information:
- To connect the breakout box, see Connecting the breakout box, 4T65EV-GT Connecting the Breakout Box
- 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 cable harness, see Wiring harness / oil temperature sensor, replacing Removal and Replacement
- To replace the temperature sensor, see Temperature sensor fluid gearbox, replacing Service and Repair
- For information about signals, see Signal specification, 4T65EV-GT Signal Specification
- For information about the resistance values, see Component resistance values, 4T65EV-GT Component Resistance Values
- Checking wiring and terminals Checking Wiring And Terminals
Continue - Resetting Transmission fluid change counter
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Resetting the "Transmission oil change" 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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Verification
Hint: After carrying out the repair check that the fault has been remedied.
- Ignition off.
- Reinstall connectors, components etc.
- Ignition on.
- Read off oil temperature.
Check that the transmission oil temperature is within its permitted range. Compare with the transmission temperature.
Is the oil temperature within its permitted range?
Yes - Verification completed
No - Fault-tracing information
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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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Attempt New Test - Checking the function of the oil temperature sensor
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Intermittent fault
Check the control module and automatic transmission connector. Check for contact resistance and oxidation. Remedy if necessary.
Check the cable between control module terminal #A37 (#A37) and transmission connector (control module side) terminal #11. Check for an intermittent open-circuit. Check for an intermittent short-circuit to supply voltage.
Check the cable between control module terminal #A55 (#A55) and transmission connector (control module side) terminal #12. Check for an intermittent open-circuit. Check for an intermittent short-circuit to supply voltage.
Remedy as necessary.
Other information
- To connect the breakout box, see Connecting the breakout box, 4T65EV-GT Connecting the Breakout Box
- 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
- For information about signals, see Signal specification, 4T65EV-GT Signal Specification
- Checking wiring and terminals Checking Wiring And Terminals
Continue - Fault-tracing information
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Fault-tracing information
Information
Fault-tracing information
If the fault is intermittent, do not verify fault-tracing if the fault does not recur.
It is possible to view the information again, or leave fault-tracing for this diagnostic trouble code (DTC).
Do you want to view the information again?
Yes - Attempt New Test
No - Exit fault-tracing
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Attempt New Test - Checking the function of the oil temperature sensor
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