Signal Too High

Signal too high

Checking the power supply








- Ignition on
- Read off the power supply for the transmission control module (TCM).
The voltage must be approximately battery voltage.
- Start the engine. Allow the engine to idle
- Read off the power supply for the transmission control module (TCM) again.
The voltage must be raised to 13-15 V depending on the generator (GEN) charging voltage.

Select an option:
1. The voltage is normal
2. Voltage too low
3. Voltage too high.










1 - Checking the components and wiring

2 - Checking battery voltage

3 - Checking the power supply

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Checking battery voltage




- Start the engine. Allow the engine to idle
- Expose the battery
- Connect a voltmeter between the battery positive and negative terminals.
The voltmeter should read 13-15 V depending on the generator (GEN) charging voltage.









Is the voltage OK?

OK - Checking wiring and terminals

Not OK - Checking the power supply

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Checking wiring and terminals
Check the connector for the transmission control module (TCM). Check for contact resistance. Check for oxidation.
Check the power supply cable (30-supply) between the fuse in the integrated relay/fusebox in the engine compartment and transmission control module (TCM) terminal #A1 (#31). Check for an open-circuit. For information about the cable routing, see the relevant Wiring Diagram.
Check the power supply cable (15-supply) between the fuse in the integrated relay/fusebox in the passenger compartment and transmission control module (TCM) terminal #A11 (#41). Check for an open-circuit. For information about the cable routing, see the relevant Wiring Diagram.

Hint: On ignition, the voltmeter should indicate battery voltage at both terminals.

Check the ground lead between the ground terminal and transmission control module (TCM) terminal #A9 (#39). Check for an open-circuit. For information about the cable routing, see the relevant Wiring Diagram.
Remedy as necessary.

Other information:
- Connecting the breakout box, AW55-50/51SN Connecting Breakout Box, Transmission Control Module (TCM)
- Signal specification, AW55-50/51SN Signal Specification, Transmission Control Module (TCM)
- Checking wiring and terminals Checking Wiring and Terminals
- To disconnect the transmission control module (TCM), see: Transmission control module (TCM) Service and Repair













Continue - Verification

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Checking the power supply
Check the vehicle charging system for a charge that is too low.
Remedy as necessary.





Continue - Verification

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Checking the power supply
Check that no battery charger is connected with too high a charge voltage.
Check the vehicle charging system. Check for too high a charge voltage.
Remedy as necessary.





Continue - Verification

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Checking the components and wiring
The fault-tracing indicates that the transmission control module (TCM) has previously registered a fault but that the fault is no longer active.
Check the connector for the transmission control module (TCM). Check for contact resistance. Check for oxidation.
Check the power supply cable (30-supply) between the fuse in the integrated relay/fusebox in the engine compartment and transmission control module (TCM) terminal #A1 (#31). Check for an intermittent open-circuit. For information about the circuit, see the relevant Wiring Diagram.
Check the power supply cable (15-supply) between the fuse in the integrated relay/fusebox in the passenger compartment and transmission control module (TCM) terminal #A11 (#41). Check for an intermittent open-circuit. For information about the cable routing, see the relevant Wiring Diagram.

Hint: On ignition, the voltmeter should indicate battery voltage at both terminals.

Check the ground lead between the ground terminal and transmission control module (TCM) terminal #A9 (#39). Check for an intermittent open-circuit. For information about the circuit, see the relevant Wiring Diagram.

Hint: The diagnostic trouble code (DTC) may have been stored by the battery charger previously having been connected with too high a charge voltage.

Remedy as necessary.

Other information:
- Connecting the breakout box, AW55-50/51SN Connecting Breakout Box, Transmission Control Module (TCM)
- Signal specification, AW55-50/51SN Signal Specification, Transmission Control Module (TCM)
- Checking wiring and terminals Checking Wiring and Terminals
- To disconnect the transmission control module (TCM), see: Transmission control module (TCM) Service and Repair













Continue - Diagnostic trouble code (DTC) information

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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 power supply for the transmission control module (TCM).
The voltage must be approximately battery voltage.
- Start the engine. Allow the engine to idle
- Read off the power supply for the transmission control module (TCM) again.
The voltage must be raised to 13-15 V depending on the generator (GEN) charging voltage.





Is the voltage OK?

Yes - VERIFIED

No - VERIFICATION FAILED

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VERIFIED - FAULT FOUND

VERIFICATION FAILED - 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 power supply

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Diagnostic trouble code (DTC) 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 - FAULT FOUND

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Attempt New Test - Checking the power supply

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