Short Circuit To Supply

Short circuit to supply

Checking system pressure solenoid STH

- Ignition on.
- Select scrolling values.
- Read off current in solenoid circuit.
- Depress accelerator pedal (AP) slowly.

The current should decrease as the accelerator pedal (AP) is depressed.

OK - Checking for a short-circuit

Not OK - Connecting the test box
Connecting the test box

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Connecting the test box

Connecting the breakout box
981 3190 Replaced by 9511428 981 3190 Replaced by 951 1428 981 3195 ADAPTOR 981 3195 Adaptor
Connecting the breakout box (Automatic transmission)

Is the breakout box connected to the control module?

Yes - CONNECTED

No - Connecting the breakout box

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Connecting the breakout box

Connecting the breakout box
981 3190 Replaced by 9511428 981 3190 Replaced by 951 1428 981 3195 ADAPTOR 981 3195 Adaptor
Connecting the breakout box

Caution! The control module power supply must be disconnected when connecting or disconnecting the breakout box, otherwise it may be damaged.

- Ignition off
- Disconnect the transmission control module (TCM).
- Connect adapter 981 3195 ADAPTOR 981 3195 Adaptor to transmission control module (TCM) connector and connect breakout box 981 3190 Replaced by 9511428 981 3190 Replaced by 951 1428 to adapter.

Note! Ensure that the adaptor is the right way round - with the breakout box cable harness outwards towards the fender.

Select "Continue"

Continue - DONE

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DONE - Checking ground terminals

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Checking ground terminals

- Ignition off.
- Control module disconnected.
- Turn of all equipment in the car that takes power from the battery (the interior lighting and radio etc).
Connect an ohmmeter between the battery negative terminal and:
#20 (#A20) on the breakout box
#29 (#A29) on the breakout box.

The ohmmeter should read approximately 0 ohms for all readings

OK - No Fault Found

Not OK - Checking for an open-circuit, contact resistance and oxidation

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Checking for an open-circuit, contact resistance and oxidation
Check ground terminals 31/32 and 31/33 and cables between ground terminals and control module #A20 and #A29 for an open-circuit according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault , and contact resistance and oxidation according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.
Check ground lead between battery and bodywork for an open-circuit according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault , and contact resistance and oxidation according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.

Select "Continue" when the fault has been repaired.

Continue - Verification

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Verification

Verification

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

- Ignition off
- Turn of all equipment in the car that takes power from the battery (the interior lighting and radio etc).
- Control module disconnected.
Connect an ohmmeter between the battery negative terminal and:
#20 (#A20) on the breakout box
#29 (#A29) on the breakout box.

The ohmmeter should read approximately 0 ohms for all readings

OK - VERIFIED

Not OK - 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 be diagnosed and remedied. Since this is not the case the fault-tracing process has failed.
Complete the fault-tracing for those fault or try again.

Do you want to terminate fault-tracing at this time?

Yes - Exit fault-tracing

No - Attempt New Test

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Attempt New Test - Checking ground terminals

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CONNECTED - Checking resistance in solenoid STH circuit

FAULT FOUND - Checking resistance in solenoid STH circuit

No Fault Found - Checking resistance in solenoid STH circuit

FAULT-TRACING FAILED - Checking resistance in solenoid STH circuit

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Checking resistance in solenoid STH circuit

- Ignition off.
- Transmission control module (TCM) disconnected.
Connect an ohmmeter between #22 (#A22) and #23 (#A23) on the test box.

The ohmmeter should read 2-6 ohms.

OK - Checking the control signal cable for a short-circuit to supply voltage

Not OK - Checking solenoid STH circuit in the transmission

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Checking solenoid STH circuit in the transmission

- Ignition off.
- Remove the air cleaner (ACL) housing to access the transmission connector.
- Disconnect the transmission connector.
Connect an ohmmeter between the transmission connector terminals 24 and 25 (transmission side).

The ohmmeter should read 2-6 ohms.

OK - Checking for a short-circuit

Not OK - Checking resistance in solenoid STH

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Checking for a short-circuit
Check cables between transmission connector terminals 24 and 25 and transmission control module (TCM) #A22 and #A23 for a short-circuit to each other.

- Ignition off.
- Open the control system according to Inspecting / replacing solenoids Inspecting / Replacing Solenoids.
- Disconnect solenoid STH.
Connect ohmmeter between the pins in the solenoid connector.

The ohmmeter should read 2-6 ohms.

OK - Checking for a short-circuit

Not OK - Replacing component

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Checking for a short-circuit
Check cables between solenoid STH and the transmission connector terminals 24 and 25 for a short-circuit to each other.

Select "Continue" when the fault has been repaired.

Continue - Checking the transmission control module (TCM)

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Replacing component

- Ignition off.
Replace transmission control system according to Control system, replacing Control System, Replacing.

- Ignition off.
- Test box connected
- Connect transmission control module (TCM)
- Ignition on.
Connect a voltmeter between #22 (#A22) and #29 (#A29) on the test box.

The voltmeter should read 0-6 V.

OK - Checking signal cable for short-circuit to supply voltage

Not OK - Checking for a short-circuit

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Checking for a short-circuit
Check cable between solenoid STH and transmission control module (TCM) #A22 for a short-circuit to supply voltage according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.

- Ignition on.
Connect a voltmeter between #23 (#A23) and #20 (#A20) on the test box.

The voltmeter should read 0-2 V.

OK - Checking the transmission control module (TCM)

Not OK - Checking for a short-circuit

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Checking for a short-circuit
Check cable between solenoid STH and transmission control module (TCM) #A23 for a short-circuit to supply voltage according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.

Select "Continue" when the fault has been repaired.

Continue - Checking the transmission control module (TCM)

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Checking the transmission control module (TCM)

Hint: The transmission control module (TCM) can malfunction if there has been a short-circuit to supply voltage in the solenoid STH circuit. Check the transmission control module (TCM) as follows:

- Ignition off.
- Connect connector and reinstall air cleaner (ACL) housing.
- Ignition on.
- Select scrolling values.
- Read off current in solenoid circuit.
- Depress accelerator pedal (AP) slowly.

The current should decrease as the accelerator pedal (AP) is depressed.

OK - Checking system pressure.

Not OK - Replacing component

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Replacing component

- Ignition off.
Try a new transmission control module (TCM) according to Replacing transmission control module (TCM) Replacing Transmission Control Module (TCM).

Caution! It is important that the solenoid STH circuit is not short-circuited to battery voltage. A short-circuit can damage the new transmission control module (TCM).

Select "Continue" when the fault has been repaired.

Continue - FAULT FOUND

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Checking for a short-circuit
Check cable between solenoid STH and transmission control module (TCM) #A22 and #A23 for an intermittent short-circuit to supply voltage according to Checking wiring and terminals. Intermittent faults Checking Wiring and Terminals. Intermittent Faults and intermittent short-circuit to each other.

Select "Continue" when the fault has been repaired.

Continue - Checking system pressure.

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Checking system pressure.
Diagnostic trouble code (DTC) AT-123 indicates a risk that transmission system pressure may be too low, which will result in increased wear. Always check the transmission system pressure.
Check system pressure according to System pressure and stall speed check System Pressure And Stall Speed, Check.

Is system pressure OK?

Yes - Test driving

No - Checking transmission control module (TCM) operation

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Checking transmission control module (TCM) operation

- Ignition off.
- Disconnect the old transmission control module (TCM) and install a new transmission control module (TCM).
Check system pressure again according to System pressure and stall speed check System Pressure And Stall Speed, Check.

Is system pressure OK?

Yes - Fault-tracing information

No - Checking control module operation, continued.

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Fault-tracing information
The old transmission control module (TCM) is defective.

Continue - FAULT FOUND

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Checking control module operation, continued.

- Ignition off.
- Reinstall the old transmission control module (TCM)

Continue - Test driving

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Test driving
- Make the car ready for test driving
- Test drive car according to Test Drive Form, description Test Drive Form, Description.
Note transmission performance during test drive.
for further symptoms.

Is the transmission free of mechanical symptoms?

Yes - Fault-tracing information

No - Replacing component

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Fault-tracing information
The transmission is operating correctly.

Continue - FAULT FOUND

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Replacing component

- Ignition off.
Try a new control system according to Control system, replacing Control System, Replacing.

Select "Continue" when the fault has been repaired.

Continue - Verification

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Verification

Verification
- Make the car ready for test driving
- Test drive car according to Test Drive Form, description Test Drive Form, Description.
Note transmission performance during test drive.

Is the transmission free of mechanical symptoms?

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 system pressure solenoid STH

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