Signal Too High

Signal too high

Checking transmission fluid temperature sensor




- Ignition off
- Check the control module and transmission connectors. Check for contact resistance and oxidation according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault. Remedy if necessary
- 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 Replacing the transmission control module (TCM), AW55-50/51SN Service and Repair
- To disconnect the transmission connectors, see Transmission connectors, AW55-50/51SN Transmission Connectors.

Note! The transmission temperature sensor is located inside the control unit and can be affected by the heat given off by the solenoids.





Was the transmission temperature within its permitted range?

Yes - FAULT FOUND

No - Checking transmission fluid temperature sensor

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Checking transmission fluid temperature sensor








- Ignition off
- Disconnect the light gray 8-pin transmission connector.
Check the temperature sensor by measuring the resistance between terminals #7 and #8 on the light gray 8-pin transmission connector (transmission side).
The resistance must be 4.5-6 kohms at 20°C.









Was the resistance OK?

Yes - Checking the wiring and component

No - Checking the cable and component

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Checking the wiring and component
Check the cable between control module terminal #24 and terminal #7 on the light gray 8-pin transmission connector (control module side). 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 supply voltage according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.
Check the cable between control module terminal #39 and terminal #8 on the light gray 8-pin transmission connector (control module side). 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 supply voltage according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.
Remedy as necessary.

Other information:
- To connect the breakout box, see Connecting the breakout box, AW55-50/51SN Connecting The Breakout Box
- To disconnect the transmission connectors, see Transmission connectors, AW55-50/51SN Transmission Connectors
- For information about signals, see Signal description. Transmission control module (TCM), AW55-50/51SN Signal Description.









Was a fault detected?

Yes - Verification

No - Checking the cable and component

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Checking the cable and component








- Ignition off
- Open the transmission control system.
Check the cables between terminal #7 on the light gray 8-pin transmission connector and temperature sensor terminal #1 and between terminal #8 on the light gray 8-pin transmission connector and temperature sensor terminal #2. 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 supply voltage according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault. Also check the cables for a short-circuit to each other.

Hint: Check the temperature sensor. With the ignition off and the light gray 8-pin connector transmission disconnected, measure the resistance between connector terminals #7 and #8 (transmission side). The resistance must be 4.5-6 kohms at 20°C.

Remedy as necessary.

Other information:
- To connect the breakout box, see Connecting the breakout box, AW55-50/51SN Connecting The Breakout Box
- To disconnect the transmission connectors, see Transmission connectors, AW55-50/51SN Transmission Connectors
- To open the transmission control system and to check or replace the temperature sensor, see Replacing the cable harness for the control system, AW55-50/51SN Service and Repair
- For information about signals, see Signal description. Transmission control module (TCM), AW55-50/51SN Signal Description.













Continue - Resetting the oil quality counter

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Resetting the oil quality counter





Resetting the "Transmission fluid change" counter

Resetting the "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 incorrectly. Therefore it is important that the "Transmission oil change" counter is reset.

Note! This only applies when the transmission fluid is changed and when the fluid is changed during repairs to the transmission temperature sensor.




- Ignition on.
Click on the VCT2000 symbol to reset the counter.





Continue - DONE

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DONE - 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.
- Ignition on
- Read off the oil temperature.
Check that the transmission oil temperature is within its permitted range.
Compare with the transmission temperature.

Note! The transmission temperature sensor is located inside the control unit and can be affected by the heat given off by the solenoids.





Is the oil temperature within its permitted range?

Yes - VERIFIED

No - VERIFICATION FAILED

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VERIFICATION FAILED - Fault-tracing information

VERIFIED - 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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Attempt New Test - Checking transmission fluid temperature sensor

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