Signal Missing. Permanent Fault

Signal missing. Permanent fault

Checking the transmission input speed sensor signal




- Ignition off
- Check the control module and transmission output speed sensor connectors. Check for contact resistance and oxidation according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault
- Start the engine. Allow the engine to idle
- Read off the transmission input speed.
Depress the accelerator pedal (AP) and check that engine speed (RPM) is updated. Compare with the engine speed (RPM).





Is the speed updated?

Yes - FAULT FOUND

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 adapter951 1505 Adapter 20 pin 951 1505 Adapter 20 Pin and breakout box981 3190 Replaced by 9511428 981 3190 Replaced by 951 1428 to the transmission connector (control module side).
Check the power supply cable between transmission control module (TCM) terminal #59 (#A59) and transmission connector terminal #S (#A16). Check for an open-circuit. See Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.
Check the signal cable between transmission control module (TCM) terminal #41 (#A41) and transmission connector terminal #V (#A19). Check for an open-circuit. See Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.

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.









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. See Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.
Check the signal cable between transmission connector terminal #V (#A19) and transmission input speed sensor connector terminal #B. Check for an open-circuit. See Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.
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
- For information about signals, see Signal specification, 4T65EV-GT Signal Specification.









Continue - Resetting the adaptation and oil quality counter

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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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Verification




Verification

Hint: After carrying out the repair, check that the fault has been remedied.








- Ignition off.
- Reinstall the connectors, components etc.
- Start the engine and let it idle.
- Read off the transmission speed.
Depress the accelerator pedal (AP) and check that engine speed (RPM) is updated. Compare with the engine speed (RPM).





Is the speed updated?

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 transmission input speed sensor signal

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