Faulty Signal
Faulty signal
Checking the gear-shift position sensor
- Ignition on
- Select the correct type of gear selector assembly. Read off the position of the gear-shift position sensor.
Shift the gear selector to all gear positions several times. Check that the gear positions are updated. The gear position sensor is incorrectly adjusted if the display shows an undefined position (OR for example).
Adjust the gear-shift position sensor if necessary. Then re-check the gear-shift position sensor.
Other information:
- To adjust the gear-shift position sensor, see Gear selector cable, adjusting Adjustments
- To access the transmission connector, see Connecting the breakout box, GM automatic transmissions, 4T65EV-GT Connecting the Breakout Box, GM Automatic Transmissions
- To access the control module connector, see Connecting the breakout box, 4T65EV-GT Connecting the Breakout Box.
Select an option:
1. The gear positions are updated correctly
2. The gear positions are not updated correctly
3. The gear-shift position sensor has been adjusted.
1 - Intermittent fault
2 - Checking the wiring
3 - Verification
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Checking the wiring
- Ignition off
- Connect the breakout box
- 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 wiring between the transmission connector (control module side):
- terminal #F (#A6) and control module terminal #A46 (#A46) "A"
- terminal #G (#A7) and control module terminal #A64 (#B4) "B"
- terminal #H (#A8) and control module terminal #A45 (#A45) "C"
- terminal #J (#A9) and control module terminal #A63 (#B3) "PA".
check for an open-circuit. Check for a short-circuit to ground. Check for a short-circuit to supply voltage.
Other information:
- To connect the breakout box to the control module, 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 Description
- Checking wiring and terminals Checking Wiring And Terminals
Select an option:
1. No fault detected
2. Open-circuit in the wiring or a short-circuit to ground
3. Short-circuit to supply voltage in the wiring.
1 - Checking the control module
2 - Verification
3 - Checking the gear-shift position sensor
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Checking the control module
- Ignition off
- Breakout box connected to the control module
- Transmission connector disconnected
- 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 (transmission side)
- Ignition on
- Read off the status for the inputs to the gear-shift position sensor (A, B, C, PA).
Check that the status is HIGH for all inputs to the gear-shift position sensor (A, B, C, PA).
Ignition off.
Temporarily connect a cable between the connector for the transmission (transmission side) terminal #A53 (#A53) and the transmission connector (control module side), see terminals according to the table.
Caution! Carefully check that the correct terminals are connected. Also check that there is no risk of short-circuits.
Ignition on.
Check that the status of the inputs for the gear-shift position sensor change to LOW when reading off the status.
Read off the status after every new connection.
The control module is defective if the status does not change. If this is the case replace the control module.
Other information
- To connect the breakout box to the control module, 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 Description
- To access or replace the control module, see Transmission control module (TCM), replacing, B5254T2, AW50/51 AWD, B5254T2, AW55-50/51SN Service and Repair.
Was the control module defective?
Yes - Verification
No - Checking the wiring and component
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Checking the wiring and component
- Ignition off
- Breakout box connected to the control module
- Open the transmission control system
- 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 (transmission side).
Check the wiring between the transmission connector and:
- terminal #F (#A6) and gear-shift position sensor terminal #E
- terminal #G (#A7) and gear-shift position sensor terminal #D
- terminal #H (#A8) and gear-shift position sensor terminal #C
- terminal #J (#A9) and gear-shift position sensor terminal #B
- terminal #K (#A10) and gear-shift position sensor terminal #F.
check for an open-circuit, a short-circuit to ground and a short-circuit to supply voltage.
Other information:
- To open the transmission control system, see Side cover transmission, replacing Side Cover Transmission, Replacing
- To connect the breakout box to the control module, 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 Description
- Checking wiring and terminals Checking Wiring And Terminals
Were any faults found in the cable?
Yes - Resetting the adaptation and oil quality counter
No - Replacing the component
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Replacing the component
The gear-shift position sensor is not available a replacement component. Replace the transmission. See Gearbox, removing Gearbox, Removing and Gearbox, installing Gearbox, Installing.
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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Checking the gear-shift position sensor
Hint: The gear-shift position sensor may malfunction if there has been a short-circuit to supply voltage in the signal cable. Check the gear-shift position sensor as follows:
- Ignition off
- Transmission connector connected
- Control module connected.
- Ignition on
- Select the correct type of gear selector assembly. Read off the position of the gear-shift position sensor.
Move the gear selector to all shift positions a number of times. Repeatedly select the same position to check the operation of the gear-shift position sensor.
Are all positions OK?
Yes - Verification
No - Replacing the component
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Verification
Verification
Hint: After carrying out the repair check that the fault has been remedied.
- Ignition off.
- Reconnect components, connectors etc.
- Ignition on.
- Read off gear-shift position sensor position.
Move the gear selector to all shift positions a number of times, and repeatedly select the same position to check the operation of the gear-shift position sensor. If the gear-shift position sensor function is OK the cause of the fault was contact resistance or oxidation.
Are all values OK?
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 gear-shift position sensor
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Intermittent fault
- Ignition off.
Check the control module and transmission connectors. Check the ground terminal for the gear position sensor. Check for intermittent loose connections (terminals). Check for contact resistance and oxidation.
Check the wiring between the transmission connector (control module side):
- terminal #F (#A6) and control module terminal #A46 (#A46) "A"
- terminal #G (#A7) and control module terminal #A64 (#B4) "B"
- terminal #H (#A8) and control module terminal #A45 (#A45) "C"
- terminal #J (#A9) and control module terminal #A63 (#B3) "PA".
check for an intermittent open-circuit. Check for an intermittent short-circuit to ground. Check for an intermittent short-circuit to supply voltage.
Remedy as necessary.
Other information:
- To connect the breakout box to the control module, 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 Description
- Checking wiring and terminals Checking Wiring And Terminals
Continue - Fault-tracing information
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Fault-tracing 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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Attempt New Test - Checking the gear-shift position sensor
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