Signal Too High

Signal too high

Checking the transmission speed sensor signal




- Gear selector in position P.
- 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 - Intermittent fault

No - Checking wiring and sensors

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Checking wiring and sensors




- Ignition off.
Check the wiring between transmission control module (TCM) #A59 (#A59) and #A41 (#A41) and transmission connector #16 and #17 for a short-circuit to each other.
Check the power supply cable between control module #A59 (#A59) and transmission connector #16 for a short-circuit to supply voltage according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.
Check the signal cable between control module #A41 (#A41) and transmission connector #17 for an open-circuit or a short-circuit to supply voltage according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.

Hint: With the control module connected, ignition on and a voltmeter connected between transmission connectors #16 and #17 (control module side), the voltage should be between 8 and 12 V.

Remedy as necessary.

Other information:
- To connect the breakout box, see Connecting the breakout box, B5234T9, B5244T7 Connecting The Breakout Box.
- To disconnect the control module, see Replacing the gearbox control module (TCM) Replacing the Gearbox Control Module (TCM).
- To disconnect the transmission connector, see Replacement Of Control System Cable Harness With Oil Temperature Sensor.
- To check / replace the engine speed (RPM) sensor, see Replacing transmission speed sensor.
- For information about signals, see Signal description. Transmission control module (TCM), AW55-50/51SN Signal Description AW50-42.













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.
- Gear selector in position P.
- 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 - 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 transmission speed sensor signal

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Intermittent fault




- Ignition off.
Check the control module and transmission connectors for contact resistance and oxidation according to Checking wiring and terminals. Intermittent faults Checking Wiring and Terminals. Intermittent Faults.
Check the power supply cable between control module #A59 (#A59) and transmission connector #16 for an intermittent short-circuit to supply voltage according to Checking wiring and terminals. Intermittent faults Checking Wiring and Terminals. Intermittent Faults.
Check the signal cable between control module #A41 (#A41) and transmission connector #17 for an intermittent short-circuit to supply voltage according to Checking wiring and terminals. Intermittent faults Checking Wiring and Terminals. Intermittent Faults.
Remedy as necessary.

Other information:
- To connect the breakout box, see Connecting the breakout box, B5234T9, B5244T7 Connecting The Breakout Box.
- To disconnect the control module, see Replacing the gearbox control module (TCM) Replacing the Gearbox Control Module (TCM).
- To disconnect the transmission connector, see Replacement Of Control System Cable Harness With Oil Temperature Sensor.
- To check / replace the engine speed (RPM) sensor, see Replacing transmission speed sensor.
- For information about signals, see Signal description. Transmission control module (TCM), AW55-50/51SN Signal Description AW50-42.













Continue - Diagnostic trouble code (DTC) information

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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 transmission speed sensor signal

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